The Odds of You Existing: Or, Why Death Is Not the End

What are the odds that you would have come into existence? There is evidence that a great many people, both regular folks and respected philosophers and scientists, think this question at least makes sense, even though it turns out to be very difficult to actually calculate a specific number. That complication aside, most people believe that the odds are quite long.  At minimum, people usually believe a) that they exist now and b) that they might not have, had things gone differently in the time before they were conceived. Had your father gone up to bed a second earlier or later, had your mother been called away on business that week, had your parents never met, had your parents never even existed, or had Napoleon not lost at Waterloo or had Billie Holiday not sang “God Bless the Child”… And so on. The basic idea is that had that sperm not joined with that ovum, then you would simply not be. Given the incredibly huge number of ways we generally think things can go and could have gone differently than they will or did, the odds seem huge indeed. And so we are all winners, and should all be grateful.[1]

The belief that you would not exist unless one particular sperm and one particular ovum had joined—that your existence depended on the joining of those two gametes—is one of the two things this book is about. I’m going to call it the standard belief about coming into existence, or standard belief for short. I’ve found it to be widely held across all types of people, from respected scientists and philosophers to the general public, from theists who believe in souls to atheists who believe in no such thing, and from those who have thought about it deeply to those who barely give it a moment’s consideration when it comes up. Yet, there is something wrong with it. It cannot possibly be correct.

What the standard belief amounts to is that some physical factors in the world, such as your DNA, have brought you into existence. The problem with this is, where do we find the essential connection between a physical factor such as DNA and your existence? For example, why couldn’t the human being that you are have come into existence and not been you, in the same way that all of the other human beings in the world came into existence and were not you? In the same way, in fact, that a lot of other people with your same sequence of DNA could have come into existence and not been you? There’s an unlimited number of possible identical twins to you, or clones of you, and yet only one is or would be you. Why that one? Or why one of them at all, rather than none of them? Why, in fact, was your existence even a possibility in the universe at all? Why was it the case that any organism at all would have brought you into existence, rather than not?

These are deep and surprising questions that some may grasp in an instant, with a sort of vertiginous existential intuition that may seem inexpressible in words. This existential intuition can come and go, depending on your state of mind. It may strike you at completely banal and random moments or particularly profound ones. And it’s the kind of insight that tends to slip through your fingers once you’ve had it, and you quickly forget what it was about as the everyday world again overtakes your thoughts. And so, one of my aims in this book is to give you tools to grasp onto this existential intuition and hold it for long periods, so you can examine it and better understand it.

Some of you may not have ever had this existential intuition, and so you may not grasp these kinds of questions at all. The questions may seem quite mundane and easily answered, or even opaque and confusing. And, in my experience, whether or not you see the point in these questions has little to do with education or intellect. They are almost pre-philosophical, preverbal, the kind of thing a child might think of, or that some among our primal ancestors 100,000 years ago might have thought of, without any ability to express. It may just be a particular personality type that gets vexed by such questions. Another of my aims in this book then is to bring those who have never experienced this around to seeing what these questions are really about, through descriptions and stories and arguments and analysis. I want to stir in you that vertiginous and confounding experience of your own existence too.

Others of you still will immediately judge these questions to be misguided, resting on basic errors of one sort or another: it’s a Cartesian fallacy, or the self is a hallucination, or coming into existence is like winning a lottery. I’ll also speak to you. I’m going to show you why they are not misguided, why in fact they and others like them are unavoidable questions. But here’s the key: they are unavoidable, if you hold the standard belief about coming into existence that I described in the first paragraph, that you wouldn’t exist if that one particular sperm and one particular ovum hadn’t joined. This is because the standard belief implies another belief: that you exist, and exist fully, not only in the present but also in the past and future of your body and in alternate situations of your body. The connection between these two beliefs, and the reasons why these beliefs make these questions real and unavoidable, are somewhat complicated, but I will try to make them clear.

These questions and the existential intuition they elicit are what I will explore in detail in Chapter 2. The purpose of this exploration is to get you dissatisfied with the standard belief. I want you to see the problems I see with it, and to leave you wanting a better belief. This better belief about existence will be described in Chapter 4 and 5. It is the second of the two thing this book is about, and I’ll tell you what it is in a moment. First let me address what I think is a tempting but wrong answer to these riddles of our existence.

Some people might think that the unbridgeable gap between the essence of our existence and our physical human bodies points to the necessary existence of a soul. This was actually my first conclusion, many years ago, and I even wrote most of what makes up the first half of this book with that conclusion in mind. I didn’t see how any physical process like evolution or the joining of two gametes actually explained why I existed—they explained why my physical body exists, but not why I exist—and I thought the problems with the standard belief pointed to an essential mystery of existence that materialism—the  belief that all that exists is part of our material universe, i.e., that there are no gods and no souls—simply couldn’t account for. But I have come to find this false on three counts.

First, there is a perfectly good materialist way to answer these questions, to resolve these paradoxes, without bringing in a soul. This is the better belief about existence just mentioned and that I’ll tell you about in the next paragraph. Second, there are many very good reasons for not believing in a soul, and many other very good reasons for believing in materialism, so if materialism can provide satisfactory answers to our existential mysteries, then it should be our belief. I’ll give some of the good reasons for not believing in a soul in this book, but not all of them. Third, much later I will show that a soul view, even if it were plausible, wouldn’t actually provide a satisfactory answer to these questions anyway. So the choice is clear.

What then is this perfectly good materialist way to answer these questions about existence that arise when you accept the standard belief? What is the new belief about existence I argue for in this book? The short version is this: you should not believe that any particular physical factors—such as a particular set of parents, a particular pair of gametes, or a particular combination of DNA—were required for you to come into existence. You should instead believe that you would have come into existence no matter which human beings came into existence. In other words, if you weren’t the human being you are right now, you would be someone else. And this belief has a necessary and, if I may say so, quite revolutionary consequence: you should also not believe that you will cease to exist when you die. You will rather simply become someone else. Well, “simply” is the wrong word. It’s actually just about impossible for us to conceive of the correct way of viewing death under this new belief—it relates closely to the impossibility of conceiving the correct way of viewing time—but it is something like becoming someone else. Something like becoming all people, all conscious beings, in fact. It is at any rate definitely not ceasing to exist, any more than living another ten years of your life right now would be ceasing to exist. If you are happy that you will exist in ten years should your human body survive to that point, then you should also be happy (if not quite equally happy, because of the loss of all the content of your life) that you will exist after your human body dies and you become another human body or other physically embodied conscious being. You can think of it as a sort of materialist reincarnation.

I don’t blame you if you are wondering how any kind of reincarnation could be materialist, could be true without the existence of souls. It is difficult to conceive. If I’m just a material object, then what exactly is it that survives, or moves to the next body, upon the death of this one? This is not a question that has an answer, but once you understand how we arrive at the belief in materialist reincarnation in Chapter 4 and 5, you will see that it needs no answer. More fundamentally, once you understand from Chapter 2 what is wrong with believing that you only exist because of the coming into being of the human body you are now, in other words, because of the joining of a certain sperm and ovum, then this resistance to any alternative materialist view disappears. You see that you’ve been tacitly assuming your existence to be something it cannot be, something that is incoherent in the details. There is simply no way to make the standard belief consistent or non-paradoxical. It must be amended.


It is always a challenge to write a book for multiple different readers, and a great many people have done it before me, so I won’t bemoan my difficulties doing it here. I’ll simply point out that that’s what I’ve done, and the result is that in some places I’ll be addressing some people more directly than others. I’ve had to include much that speaks directly to professional philosophers and well-read amateurs such as myself who already know this topic very well and already have strong opinions on it. There is a lot of existing philosophy on this topic, and I intend this book to be fully a part of that discussion, drawing deeply and widely from it and adding several new ideas to it. But by far my greatest guiding principle has been to speak mostly to those who are unfamiliar with that existing philosophy, who may be unfamiliar with philosophy at all in fact, but who are nonetheless very interested in their own existence and death. In service of this goal, I aim to never stop you short by presenting a discussion to which you feel you have not been invited. I try always to start from widely shared and easily understood terms and facts and principles, and to move step by step from there into the heights of abstraction and analysis, where we must necessarily go if we are to discover what we should really believe about our own existence.

One consequence of this is that expert readers may find my terminologies not quite precise enough at the beginning. In order to ease people into the discussion, I will start by just using the common terms people usually use and tacitly assume are used by everyone to mean the same thing. We will discover that this is not always the case, and so I will slowly get more and more precise as we go along. Another consequence is that not everything I write here is absolutely essential for every person to understand in order to follow the argument. Sometimes I may be addressing objections you never even thought of and don’t feel the need to hear about, or may be arguing for things you already believe in the effort to convince those who don’t. I’ll mark some of these off in the text (the next paragraph is one), and I’ve provided a reading guide in the appendix that gives advice on how different types of readers might get directly to the points they’re most interested in. I don’t necessarily recommend going there now, as I’d like to think anyone could just read this book from one page to the next like any other book. But you can keep this reading guide in mind as a sort of lifeline as you make your way through the argument.

For the experts, I’ll give you a little secret signaling here and now to let you know where I’m going. There is an alternate belief to materialist reincarnation that I will introduce, an alternate solution to the paradoxes I’ve presented. You may have been thinking of it already. It is the belief espoused by, for example, Derek Parfit, in Part 3 of his book Reasons and Persons. Parfit is one of the great influences on and inspirations of this present work, and I will spend some time discussing him in my own Chapter 3. To sum up, I think we should take most of what he says about personal identity as being correct, but it should be amended where needed to lead us to my new belief, materialist reincarnation, which maintains the common sense intuition of persisting existence through time that I argue for here (in Chapters 1 and 3) while accepting the almost irresistible force of Parfit’s analysis of personal identity. And there is one point where I think Parfit himself is self-contradictory, because he affirms the standard belief about coming into existence—at the very beginning of the fourth part of Reasons and Persons—yet I find that accepting the standard belief doesn’t really accord with his own view of personal identity. Notably, this has implications for Parfit’s famous Non-Identity Problem, as that problem rests on acceptance of the standard belief. All of this will be explained for both experts and interested non-experts in Chapter 3.


There is one issue we need to settle before we get to any of these things though, and that is a question that has likely been nagging some of you since the beginning of this introduction: just what exactly do I mean by my or your “existence” anyway? I keep saying that term and making bold claims about it, as though we all know exactly what I mean. But do we?

Almost certainly not. Some people mean what I mean by it. Some people consciously do, a great many more unconsciously. Some people reject what I mean by it, or at least think they do. Some people have no idea what I mean by it. Some people quite explicitly mean something different by it, and will argue at length for their own meaning, and that I am dead wrong. And so, we must get this straight before we do anything else. This I will do in Chapter 1, aptly titled “Foundations”, where I provide an answer to the question, “What do we all mean when we say ‘I exist’?” What are we referring to or verbally “pointing at” when we say that? Or, to put it in more immediate terms: What is the actual thing you’ve been thinking about this whole time every time I’ve talked about your existence? Stop and reflect on that for a moment. Many people would never even suspect this to be a question that needs answering. But it does. You may think it’s obvious that we are all talking about the same thing when we talk about existence, but it’s not.

To give you a preliminary idea of what I will be aiming to accomplish in the first chapter, let me first point out two things people think they mean when they say “I exist” that I consider wrong, or at least not always right.

Some people consider their existence to be a construction, built up over years of socializing and education and the like, and situated within a context of a culture and community of people. Some would go so far as to say this entirely defines what they mean when they say “I exist”. They are simply the bundle of these ideas and attitudes and everything else they’ve collected over the years. This is a fine and important answer, but it is an answer to a different question than the one I’m asking, though the form of the question may sometimes appear the same. It is thus the right answer only some of the time. This construction, social or otherwise, is a major part of what I will call “content”, the content of our lives and thoughts, and is distinct from what I’m going to call “existence”. One of my primary goals in fact is to isolate our concept of existence from content, to avoid the muddles we often get into when discussing existence. The weightiest tool I will bring to bear on this task is a science fiction thought experiment I call the perfect doppelgänger, which takes up a large portion of Chapter 1. It involves imagining an exact replica of you, replacing you in the world, that isn’t you, but rather is someone else. (Some people will strenuously resist this attempt to separate content from existence, so if you find yourself wondering why I am going on at such length in the first chapter to establish this isolation, that is why.)

Alternately, some people just assume, quite naturally and sensibly, that when they say “I exist” they are simply saying that a particular human being exists, the one produced by those two gametes many years ago with that particular DNA. In other words, they claim that what is happening there is 1) they are a human body, and 2) that human body is uttering the words “I exist”, referring to itself, and that’s all there is to it. This too is right, but again only some of the time. Some of the time, especially when we are asking questions about our existence such as those I pose in this book, we are not actually talking about a human body. And this is so even for some who strongly insist they are. At least I suspect so. I will give you my reasons why near the end of Chapter 1.

The thing I want to show you, the actual referent of “I exist”, the thing we are actually “pointing to” when we say that, is not either of these things. And it’s not so straightforward as they are, not so easy to describe or point out, which may help to explain why those two things are often mistaken for it. It is a more inchoate concept, and it may take some work before you see it. I’ll get to my attempts to show it to you after a few more words of introduction.


The survival of death I’ve promised you will undoubtedly be good news for a great many people, just for purely selfish reasons, if nothing else (though it does have its downsides too, which I will also look at). But it has other salutary effects as well. It goes some way toward dissolving the ego, that pernicious imaginary entity we (some of us) work so hard to protect, at the expense of so much that is so much more important. But even if we can’t get rid of self-interest altogether, materialist reincarnation widens the scope of such self-interest to the point that it includes not just yourself and things that affect you, but everyone and everything that affects anyone. Your project becomes not just making your own life good and achieving some sort of progress in it, but making all lives good and, if you have this particular bent, achieving some sort of progress with the tremendous knowledge-creating power humanity and other higher consciousnesses possess. We find there is an essential unity to all of the apparently separate existences of different people, even in a purely material universe. (If this sounds like Buddhism to you, that is coincidental, but not wrong.) If this view is true and belief in it becomes widespread, I feel it could not help but drive people to create a better world than the one of environmental desolation and grave injustices that humanity is currently perpetuating.

I’ll discuss these possibilities and more in Part II, Meaning in a Material World. What I described previously in this introduction, Chapters 1–5, are tied together as Part I, Analysis. I have separated the two because Part I is an argument for why you should believe a certain way about your existence, while Part II is an essay about how that belief can transform your life, and maybe even the world. (I’m an optimistic realist about that.)

One of the main threads of the discussion in Part II is the question of why we feel we need mystery, such as the mysterious ways of God, in order to have meaning. I think we wrongly conflate mystery and meaning a lot of the time. Among other things, this causes us to be afraid of or even resistant to actual explanations of reality in places where we had previously found the mystery comforting. If my view does indeed banish the last remaining shred of mystery about our existence (aside from the probably unanswerable question of why there is something rather than nothing), as I will eventually claim it does, then finding meaning and comfort in a world without an overriding insoluble mystery will become very important to our individual and collective well-being.


I’ve given you a lot of detail in this introduction, and probably not all of it makes sense yet to everyone. So let me finish with a recapitulation and distillation of the essential ideas and methods in the most direct language I can muster.

The big news of this book is that it contains two vital discoveries with the potential for great and immediate practical impact on your life and well-being. The first is that death is not annihilation. You do not cease to exist when you die. Nobody does. Not even atheists. I know a great many people are like me and have been terrified of this annihilation since it first occurred to them. Well, I’m here to tell you that this problem has been solved. Even without any spiritual realm whatsoever, you will not live just the life of the human body you are now. You will live many more. And I mean this literally, as literally as the idea that you will exist ten years from now should your body survive that long. I don’t mean the often-made weaker claim, that you will survive death in the sense that your influence and ideas and love will survive in the hearts and minds of other people. No, I mean you will literally be those other people, as literally as you are you right now. And to reach this conclusion, no emotional or mystical appeal is necessary. All it takes is a cold logical step-by-step argument, demonstrating first what you really mean when you talk about your existence, and then showing that it doesn’t make sense to think of that existence as coming into being only with the coming into being of a particular human body and persisting only for the lifespan of that human body.

The second discovery I just mentioned: if you are/become all people, then the interests of humanity (more accurately, the interests of everything that is conscious) become your own interest. I cannot overstate how exciting this is, so let me recap. It not only gives you more concern for how well the lives of others go, but it gives your own life much greater scope for meaning. In as much as you currently find meaning in making intellectual and moral progress in your life, learning from mistakes, and cultivating your own small corner of community and relationships with others, you can now look ahead not just to the span of your life and the few people you care about or will influence, but to the span of the existence of conscious life as a whole, to the great project of humanity. This project now literally becomes your own, just as much as the project for your own life has been your own. Anyone who despairs at the pointlessness or insignificance of their single short human life—”you do a few things then you die”—should find this encouraging, and inspiring for action.

These are the exciting things in this book, the reason I expect you to want to read it at all. However, we must be careful: thinking about them before their time comes up here would be a distraction. This book is indeed about those two great discoveries, but it is actually mostly about (your) origins, and understanding what is inexplicable about them. In other words, understanding what is wrong with our commonly held beliefs about them. Origins is the topic we’ll start with and spend most of our time on. It is the topic that originally vexed me, and that I spent many years on without any glimmer of the conclusions I’ve come to about death and meaning for life. I was just perplexed by all the purported explanations of how I came to be. The conclusions I’ve reached about death merely followed from what I concluded about origins, and the conclusions about self-interest and the good of the world followed from what I concluded about death.

I’ll give you an anchoring thought you would do well to remember: everything in this book hinges on the question of “what caused you to exist?” My method will be to show that this question is unanswerable without believing in materialist reincarnation.

[1] Unless, of course, you agree with David Benatar (2006) that coming into existence is always bad. Or perhaps Schopenhauer: “Human existence must be a kind of error. It may be said of it; ‘It is bad today and every day it will get worse, until the worst of all happens’.” Personally, I’m pro-existence.


Chapter 1: Foundations

What is your “Existence”?


People who say they don’t care about metaphysics really mean that their received ideas on such matters are so fixed that they have disappeared from consciousness, in the same way that you don’t usually notice your heartbeat.

-Adam Kirsch


The aspects of things that are most important for us are hidden because of their simplicity and familiarity. (One is unable to notice something because it is always before one’s eyes.) The real foundations of his enquiry do not strike a man at all.

-Ludwig Wittgenstein, Philosophical Investigations


[Philosophy’s] sources are preverbal and precultural, and one of its most difficult tasks is to express unformed but intuitively felt problems in language without losing them.

-Thomas Nagel, The View From Nowhere



Today you are you,

that is truer than true.

There is no one alive

who is youer than you.

-Dr. Seuss



In order to properly attack the central question of this book, “what caused you to exist?”, we first need to figure out what that word “exist” means. What it means to you personally, what I mean by it when I say it in this book, and what it means to us collectively. This is the main task of the foundations of Chapter 1. As I said in the introduction, I will be using a thought experiment I call the perfect doppelgänger to answer that question, quite definitively I think. Before we do that though, there is something even more basic we need to look at (a preliminary to the preliminary, as it were). This is the question of what you already believe about your own existence. It might not be clear at first why we need to settle this before doing anything else, but it will become so later. And this very first step is actually pulling double duty: what we accomplish here will turn out to be an essential plank of the argument of the entire book.

To some this first step may seem banal and obvious, to others obviously wrong. This is why we need to lay it all out in the open.


  1. What You Already Believe About Your Own Existence

It is a fact that you have beliefs about your own existence. It would be next to impossible for you to not. So the first thing we’re going to do is to bring out into the open some of these things you already believe about your own existence. We’re going to do this, as I said, before we even talk about what you mean when you talk about your existence. I suspect many of you don’t even know what you mean when you talk about your existence. Yet, you still have some beliefs about it. You express your beliefs about your existence not in definitions, but in the way you talk about it, unconsciously, every day. So I’m going to examine the way you talk about it, and thereby describe what you believe about it.

Now, not everyone has the same beliefs about their existence of course, so I won’t actually be describing everyone’s beliefs here. But there are certainly some beliefs that are more common than others. So the ones I’m going to be describing here are what I believe to be the most common ones. We’ll get to other beliefs later.

So here’s one thing you probably believe: if you had put this book down and stepped outside thirty seconds ago, you would be outside right now. In other words, you believe that in that situation, you would exist, and you would be outside right now. You would be the human being that is outside right now. You would not not exist. You do not believe that your stepping outside thirty seconds ago would have had the same effect on your existence (you, now) as dying thirty seconds ago would have. When you imagine the former case, you place yourself there outside right now. When you imagine the latter case you place yourself nowhere right now. You would be no human being in our physical universe right now.

            As I said, my claim that you believe these things is not a claim that you know precisely what you are talking about when you say it, but just that it is the sort of thing you would or do say regularly, without thinking about it much. If you are not primed to think about it critically or philosophically, for example, as I am doing here now. Sentences such as “I would be outside right now if I’d gone outside thirty seconds ago” are things you say (or at least think) all the time without even a glimmer of a notion that they’re propositions (or contain propositions) worth questioning, and you live your life as though they were true. This counts as a belief that you have, even if you never articulated it before. And I should point out: I think it is an eminently sound belief. I hold it as well.

            No such claims can be completely without controversy though, and there may be some who object to this one. As I said, I will come to these objections later. For now I will move ahead on the basis of the claim that this represents what most people do in fact believe. I’ll provide some evidence for this assertion in a moment.

            Now try this sentence on for size: “My parents almost moved our family to the south of France when I was five. If my parents had done that, I would probably still be there now.”[1] Setting aside the specific details of location and whether you would be likely to stay in the place in which you were raised, is this a sentence you could utter? Does it represent your belief about your existence? Would you or could you say it or something analogous that was germane to the actual circumstances and places you have and could have lived in your life (“almost moved to Texas” or “almost moved to Mumbai”, etc.), if you were in a conversation and were not consciously thinking critically or philosophically about your own existence? I would venture that almost everyone would. Perhaps a couple people fewer than would assent to saying the first sentence about stepping outside thirty seconds ago, but this is still the way most people talk and think. And so this is a belief most people have about their existence.

In other words, most people would not say, in casual conversation at least, “My parents almost moved us to the south of France when I was 5; if they had done that, I wouldn’t exist right now.” And so this is not a belief about their existence that most people hold.

            How far back in time do you trace? Could you say the same (or an analogous) sentence about being a newborn, or when your mother was pregnant with you? “My mother almost moved to the south of France when she was pregnant with me. If she had done that, I’d probably still be there now.” The further back in time we get, the more controversial it becomes for some people to claim they would or could still exist there. For others though, the truth of the statement remains exactly the same. Exactly the same; this is an important point. And I would venture that the latter is the case for the great majority of people, that still, most people would assent to the statement about their mother being pregnant, again if they were not asked to think critically or philosophically about it, just as much, and mean the same thing by it, as they would to the sentence about moving to France when they were five or stepping outside thirty seconds ago. It’s something they might utter without much thought, and so counts as a belief. They would exist there now, and exist there fully, whereas they would not exist anywhere at all if they had died. Again, doubts about this will be addressed later.

            Where does this trip backward in time end? If you trace your body back in time, you eventually come to a zygote. A zygote is the single cell that exists immediately after conception, after a sperm fertilizes an ovum. This divides and becomes multicellular, where we call it an embryo, and when the major body organs develop, we begin to call it a fetus. If your mother had moved to the south of France immediately after you were conceived, could you say “I would probably still be there [in France] now”? I think almost everyone still would say yes, they could say that. In fact, I slipped a little sleight-of-hand into my statement (and have been doing so all along). I said “immediately after you were conceived”. Can we assume it was “you” immediately after conception? Or even when “you” were five? Maybe not, but most people believe it was, because most people make such statements without thinking to question them. A great many people probably didn’t even notice this slip. And if this were a normal philosophical claim about what is true, this would be begging the question, assuming part of what I set out to prove. But I’m not trying to prove anything about your existence right now. I’m just trying to demonstrate some things about your and most people’s beliefs. And that sentence probably slipped by you, because, again, this is the way you talk about your existence already without thinking about it.

            Do people stop at the zygote in tracing their existence back in time? I claim that they do not. What people most often trace back to is the gametes that produced the zygote that produced you. Most people would probably just say this as “the gametes that produced you”.[2] And so the fundamental belief is this: we think the gametes were just as essential to our coming into existence as the zygote was, or to put it in a non-question begging way, that those gametes were just as singular and unique our antecedents as the zygote was. We think those gametes joining were essential to our coming into existence, or to our existence in the present moment. This statement may be a bit confusing with the mass pronouns “we” and “our”, so let me shift to a singular pronoun to make sure I’m being understood: You believe that that one particular set of gametes existing and joining was essential to you coming into existence. Probably. It is at least a very common belief, for anyone who has thought about it. I called this belief the standard belief about coming into existence, or standard belief for short, in the introduction. I will still use that term, but it will be useful to have a more rigid and descriptive term, so I’ll also call it the Gamete-Dependence Claim. It is the central topic of this book:

The Gamete-Dependence Claim: If the gametes that produced you had not joined, then you would not exist.

I’ve stated already that this is a common belief. I can provide evidence for this assertion. Here is one particularly eloquent statement of this claim. I will provide others later.

These are the paragraphs that begin Richard Dawkins’ book Unweaving the Rainbow:

We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who in fact will never see the light of day outnumber the sand grains of Arabia. Certainly those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here.

Moralists and theologians place great weight upon the moment of conception, seeing it as the instant at which the soul comes into existence. If, like me, you are unmoved by such talk, you still must regard a particular instant, nine months before your birth, as the most decisive event in your personal fortunes. It is the moment when your consciousness suddenly becomes trillions of times more foreseeable than it was a split second before. To be sure, the embryonic you that came into existence still had many hurdles to leap. Most conceptuses end in early abortion before their mothers even knew they were there, and we are lucky not to have done so. Also, there is more to personal identity than genes, as identical twins (who separate after the moment of fertilization) show us. Nevertheless, the instant at which a particular spermatozoon penetrated a particular egg was, in your private hindsight, a moment of dizzying singularity. It was then that the odds against your becoming a person dropped from astronomical to single figures.

The lottery starts before we are conceived. Your parents had to meet, and the conception of each was as improbable as your own. And so on back, through your four grandparents and eight great grandparents, back to where it doesn’t bear thinking about.

Dawkins then quotes from the autobiography of the British biologist Desmond Morris (b. 1928), where Morris points out that he “might not be sitting here writing these words” had one of Napoleon’s cannonballs (c. 1810) not shot off the arm of his great-great-grandfather James Morris. Dawkins finishes on this note:

There’s no “might” about it. Of course he owes his very existence to Napoleon. So do I and so do you. Napoleon didn’t have to shoot off James Morris’s arm in order to seal young Desmond’s fate, and yours and mine, too. Not just Napoleon but the humblest medieval peasant had only to sneeze in order to affect something which changed something else which, after a long chain reaction, led to the consequence that one of your would-be ancestors failed to be your ancestor and became somebody else’s instead. I’m not talking about ‘chaos theory’, or the equally trendy ‘complexity theory’, but just about the ordinary statistics of causation. The thread of historical events by which our existence hangs is wincingly tenuous.

There is a lot we can learn from this passage about what Dawkins believes. For example, he points out how improbable it was that the exact combination of DNA you have would have come into being from among the incredible number of combinations possible. We can assume then, given his goals with this passage, that he believes you would not exist without that combination of DNA. And he points out how improbable it was that your parents would have met. In the same way then, we can assume he believes you would not exist if your parents hadn’t met. In other words, he believes that a sperm and ovum with that exact combination of DNA had to come from your parents,  in order for you to exist. If it had not, you would not exist. This is the gamete-dependence claim, the standard belief about coming into existence.

It also seems safe to assume that he believes you believe these things too, because he doesn’t take any time to justify these assertions that you wouldn’t exist if these things hadn’t happened. He takes this to be an unspoken shared assumption, and uses this assumption to achieve his main purpose, which is to fill you with awe at the incredibly long odds against you coming to exist.

Now, Dawkins doesn’t provide a definition of what he means when he’s talking about existence. But as I’ve been doing all along in this section, I’m using Dawkins’ own words about existence, and taking these to be his statements of belief about his and your and my existence, whatever he takes that to be. And he assumes he is talking about the same thing you are talking about when he says it.

            Those points are relatively straightforward. There is a more important point for our purposes that is a little harder to see but just as true. Note that Dawkins places the long odds of you existing right now (almost) entirely at the point of conception or before. Nothing that happens after conception is considered in the odds of existing, as Dawkins uses the term, except the death of the conceptus or what it develops into (this is the “almost” above). This means that Dawkins accepts all the beliefs I’ve described so far, about moving to France when you were five, or a newborn, or a fetus or zygote or whatever. Whatever Dawkins means by your existence, he thinks this is a thing you would have, a thing that would obtain in the universe, wherever that conceptus and the things it develops into goes after it is created. If he didn’t believe this, then he would have had no reason to talk about the long odds of that particular conception and the events that preceded it happening. He could just as easily have said, “You are lucky your parents didn’t move the family to France when you were five years old, otherwise you wouldn’t exist right now,” in the same way he implied that “you are lucky your mother didn’t move to France before you were conceived, otherwise you wouldn’t exist right now.” He could have said that about any event in your life, and stated not the gamete-dependence claim, but the “not-moving-to-France-at-age-five-dependence claim”, and every other life-event-dependence claim. But Dawkins didn’t make that claim, and nobody else does either. Nobody makes life-event-dependence claims about their existence. If they make any claim at all, they make the gamete-dependence claim, just as Dawkins did.

So, since there’d really be no reason to bother stating the gamete-dependence claim unless you also believed this other thing about moving to France when you were five etc., it should be incorporated into the gamete-dependence claim, to make it clear and complete. So here is the full and precise version:

The Gamete-Dependence Claim (full and precise version): If the gametes that produced you had not come into being and joined, then you would not exist right now, but as long as they did come into being and then join somewhere and at some time and what developed from this conception went on to have a life as a conscious organism somewhere in the world up to the present, then you would exist right now.

So what is this claim actually about? Let me pause here and give some voice to critics. As I said in the introduction, many people will be assuming right now that what Dawkins and everyone else are talking about when they say “exist” is just the existence of a particular human body, and wonder why I am making such a big deal about it. This may even be what Dawkins himself thinks he is talking about. And it is consistent with everything he says explicitly, so it’s a possibility that cannot be rejected out of hand. But I don’t think it is what he actually means. There is another assumption hidden underneath what he says explicitly (and therefore hidden underneath what most people believe) that gives away what he is really talking about. To point out what this is, we must first get through the thought experiment in the next section. For the purposes of getting through that thought experiment, it is enough to just note that the full and precise version of the gamete-dependence claim is a complete description of the way people typically use the word “exist” in practice when referring to themselves. So whatever people mean by the word “exist”, whatever the thing is they are thinking of when they say it, these things are what they believe about it. Or at least, what most people believe about it. If you don’t wonder too hard what you believe about your existence and what you mean by your existence, it probably seems obvious to you.

            Let’s get back to the main argument now. You may have noticed that I snuck more premises into the above revised statement of the gamete-dependence claim. Note the phrase “as long as [those gametes] did come into being and then join somewhere and at some time”. In other words, I claim that those gametes didn’t have to join when and in the location they did join, but could have joined any time after their creation and in any place and you still would have been brought into existence, i.e., you would exist now if what developed from this conception went on to have a life up to the present as a conscious organism. I take this to be a true statement of the common belief because it is the most consistent thing to believe with all the other parts of the gamete-dependence claim.

Let me explain that a little more. It is rare that we imagine a pair of gametes joining at a different time than they actually did join. Much rarer than how often we imagine a human being doing something different than he or she actually did do (like moving to France, or stepping outside). So we don’t talk about it much. But it is certainly a part of our universe of possibilities. It is possible that the gametes that produced you could have joined at a different time. Even naturally, an ovum sits ready to be fertilized for about a week, and is in fact able to be fertilized for much longer, but just isn’t in a location where a sperm is likely to reach (or if it did, then a location where it can develop and grow). And a sperm can live for several days in its natural environment after being created. So that sperm could have naturally fertilized that ovum at any time over the course of a couple of days at minimum. But we modern humans have made the length of this time span much greater in recent decades through artificial means. Infinite in duration, in fact. A sperm and ovum can be frozen and saved and remain viable indefinitely, and then thawed and joined, and a human being will result. This is a pretty common procedure these days in places that have fertility clinics. If the gametes that produced you had been frozen and joined five years after they actually were, and in France rather than where they actually were joined, would you exist right now? Would the human being that resulted be you, right now?

            As I said, I think you should believe that you would exist right now, that you would be that human being. It’s the only belief that is consistent with all of the other beliefs I’ve described up until now. You’d have to have a reason to accept that you when you were five or a zygote could have gone to France and you would still exist right now, but that if just those gametes before the conception of the zygote had been taken to France and been joined there, then you would not exist; the resulting human being would have been someone else, though it came from the same gametes. I think there are surely no reasons that could be found to believe one without the other, just as there are no reasons to draw the line anywhere else between the present and the zygote. And there is no reason to treat the location of the joining of the gametes as any more variable than the time of joining. (This, incidentally, creates an intriguing possibility not often remarked upon: your younger brother or sister could have been your older brother or sister if your gametes had been frozen, and your older brother or sister could have been your younger brother or sister if their gametes had been frozen.)

            And so with this part in place, let me try just one final sentence out on you: “If the gametes that produced me, instead of joining when they did join, had been frozen and taken far out into space on a space ship and put on a space station and then thawed and allowed to join there, and then if the space ship that brought them had been destroyed and all possibility of return to earth had thereby been shut off, then I’d be on that space station right now, assuming I had survived to this moment.” Is this a sentence you could utter? (Ignore the complications of time dilation, or assume the time-difference to be sufficiently small.) Is this something you would believe? If you believe everything else I’ve said most people believe so far, then you should. It is the only thing consistent with those beliefs.

            With that settled, let’s get to the thought experiment. If, after reading all of this, you find that this still doesn’t represent your beliefs, I promise to address you after the thought experiment is complete.

  1. What Do You Mean When You Say “I Exist”?


I am now going to try to point out to you exactly what you are talking about when you say “I exist”. What you mean by it when you say it in everyday contexts, and what you have been thinking about all along as we’ve discussed it so far, including in the last section.

Let me explain a little what I mean by “what you are talking about when you say ‘I exist’”. If we were to ask the question, “what do you mean when you say ‘red ball’?”, we could point to a red ball and say “this”. And if there wasn’t an actual red ball available to point to, you would still be imagining something in your mind that you could “point to”, metaphorically, to yourself at least. “Pointing to” things, metaphorically (without using an actual finger, but just by putting our focus on it), is something we do all the time, when we wonder what we mean by something. We even do it for abstract things, such as love. Maybe to define love we might “point to” a feeling we have inside, or to characteristics of a relationship we have with someone. I’m not claiming we can have an exact or uncontroversial definition of love, or that we would all agree we are all pointing to the same things when we say the word “love”, just that when we think of love we are consciously or unconsciously pointing to something or some things in one way or another that suffice as definitions of what we mean by it for our everyday purposes, or for our purposes at that moment. This thing or these things we are pointing to when we say or think a word are the referents of that word, the thing or things we are referring to. This is the same thing I will attempt to do for the concept of existence here, for the utterance “I exist”. What are you pointing to when you say that? What is the referent? Is it a human body? Or is it something else?

I’m going to try to make this task as easy and straightforward as I can. But it may not be. So before we begin, recall the two quotes from Ludwig Wittgenstein and Thomas Nagel that I began this chapter with. They are words of wisdom and warning especially pertinent for the task at hand here. Here they are again:

[Philosophy’s] sources are preverbal and precultural, and one of its most difficult tasks is to express unformed but intuitively felt problems in language without losing them. (Nagel)

The aspects of things that are most important for us are hidden because of their simplicity and familiarity. (One is unable to notice something because it is always before one’s eyes.) The real foundations of his enquiry do not strike a man at all. (Wittgenstein)

The thing I want to show you here is preverbal and intuitively felt, and if you are not careful the torrent of words might just as well mask it or misdirect you to something altogether more prosaic as properly clear the way and guide you to it. It is not prosaic. It is quite profound. Yet, it has been always right before our eyes, and if you are not careful the torrent of words might give the impression that it is something much more esoteric and difficult to find than it is, a hidden secret somewhere in a deep chasm. It is not hidden. It is out in the open already. You might be looking at it and not even realize you are looking at it. So you just have to be trained know it when you see it.

If insight comes to you, it might well come in an instant, and words might still fail you to describe it, even if words are what led you to it. The words are just prepping you and priming you to see it, trying to point at it. They are not the thing itself.


First I will tell you a simple version of the thought experiment, to get straight to the point. Then I will tell you a long version of it, a science fiction story, to fire your imagination and convince you it could really happen.

I caution and remind you here that this story has nothing at all to do with the materialist reincarnation I mentioned in the introduction. This story is based on what most people believe right now, which is that you cease to exist when you die. Put materialist reincarnation out of your mind.

2.1 A Simple Replacement


Imagine you don’t exist. Some people claim this is impossible. In some sense I see their point, but in another sense I’m certain most of us do it quite naturally all the time. So imagine that you don’t exist. There are many ways you could do this. You could take a practical route, and imagine the time before you were born, or the time after you die. Before you were born, there was a whole world, a whole universe, containing all sorts of things, and in the recent past most of the things it contains now. But you were nowhere to be found in this world. Among these other things it contained were a lot of other people. But none of them were you. You simply didn’t exist at all, anywhere, though many other people did. The same will be true after you die.

Another way you can imagine that you don’t exist is to imagine that you were never born. Imagine that it is the actual present, right now in all of the history of the universe, but that you are nowhere to be found in it. In other words, that it is the present, but the situation in regard to your existence is the same as it was 130 years ago, or will (presumably) be 130 years from now. It is the present, but you don’t exist anywhere at all. There are other people who are not you, but there is no one and nothing that is you; your perspective, your existence, is completely absent. Just like it was before you were born or will be after you die. Imagine that it is like that now. I think this also should be easy for everyone to imagine.

You could use several practical ways to achieve this imagining that you do not exist right now as well. You could imagine that your parents had never met. Or that they had met but didn’t copulate when they did, at the time of the conception event that produced you. Or you could dispense with the practical details, and just imagine your nonexistence in the present in itself, without any further questions about it. Just think about the world as it is in this moment, then erase your existence in it completely. You don’t exist, anywhere at all. But everything else in the universe is basically the same, including there being a lot of people in it who are not you.

Now imagine something into this alternate present in which you don’t exist but a lot of other people who are not you do exist. Imagine that one of those other people who are not you is a lot like you. In fact, essentially exactly like you. Let’s say that this person is like an identical twin, with the same DNA sequence as you, though we’ll add the one stipulation that they weren’t produced from the splitting of the zygote that produced you. We’ll say that the zygote that produced you never existed in this situation we’re imagining. But this person just happens to exist who has the same DNA as you in this situation of a present in which you don’t exist. You don’t need to imagine yet the technical details of how this could come about. Just erase yourself from the world, and put someone else with your same DNA into it.

This should not be controversial, but for some I think it will be. But really, it should not be. It is easy to imagine yourself not existing. And it is easy to imagine people who are not you existing. You don’t even have to imagine for the latter; they are already all around you. And these people who are not you could have all manner of DNA. And they could have DNA that is quite close to yours, and still not be you any more than those whose DNA is quite distant. And they could have DNA that is exactly like yours and still not be you any more than those whose DNA is quite distant. (Remember that this follows from belief in the gamete-dependence claim.) So none of this should be controversial.

And if you can imagine all this, then you should be able to take these final steps. Imagine someone that is not you but that is exactly like you in every possible way, not just in DNA, but in every physical structure. And imagine this person in a present in which you don’t exist. Finally, imagine this person occupying the exact same location in space and time as you do now, doing exactly what you are doing now, and thinking exactly the thoughts you are now, including having all of the same memories you have now. You don’t exist, but this person does, exactly like you in every possible way, doing and thinking just what you are doing and thinking now. Just erase yourself from existence, and put this other person who is not you in your place.

Have you done this? Good. I call this person who just took your place your perfect doppelgänger. This person performs a very important function for you: he or she clarifies what you are actually referring to when you say “I exist”. The thing you are referring to, the thing you are pointing to with those words, is the sole difference throughout the universe between actual reality and the alternate possibility in which your perfect doppelgänger exists in your stead. That thing, that sole difference, is your existence, what you are referring to when you say “I exist”.

One big reason this is important is that it separates your existence from the content of your life. Many people think their existence is wholly defined by the content of their lives, i.e., their memories, beliefs, desires, etc., socially constructed or otherwise. But in this case, you don’t exist, and someone else has all of the exact same content as you do, the same memories, beliefs, desires etc. And so this thought experiment shows that your existence is something other than that content. The content can obtain with or without your existence. So you are not referring to content when you say “I exist.” You are referring to this other thing I have isolated here. That is your existence.

This should be profound and surprising, if you see it. It was for me. I think this existence is a thing that has always been right before our eyes, but most of us have never named it and so have never seen it, never consciously distinguished it as a thing itself. It is akin to air, or space, before we thought to consider them as their own separate entities. And this has left our discussions of our existence in a muddle. This thought experiment is an attempt to clarify this muddle, to isolate and bring this thing to light so we can all see it, and agree on what we are referring to. Then we can try to discover what is true and false about it.

This is the basic idea of the perfect doppelgänger, but there’s a story I like to tell myself that makes it much more vivid and real, and makes the conclusion seem irresistible to me. I’ll share it with you. In particular, I’m going to show you that this situation is actually physically possible in the actual universe we live in—it could have happened to you. And this shows that this existence, your existence, is a real thing in our universe, in some very important senses of the word “real”.

2.2 The Perfect Doppelgänger Thought Experiment (PD)

There is a single pair of gametes that produced you, many years ago. Picture those gametes in your mind right now, one sperm and one ovum. They were actual objects in our universe at one time. Someone could have looked at them under a microscope, or held them in a tube or dish, though probably nobody did. Probably no one ever set eyes on them at all. But someone could have. So picture in your minds’ eye right now what someone would have seen if they had.

            Let’s call this pair of gametes that produced you the A gametes, sperm A and ovum A. Label them that now in your minds’ eye; they will carry this name with them wherever they go in the universe and for however long they last, just like any other organism or object that receives a name.

Now imagine that, instead of these A gametes joining in the way they actually did join in the real world, which for most people is when their parents copulated, that they were instead extracted from your parents at some point after they produced them and, as I said at the end of section 1, taken on a ship to some location in space far from earth. Out there in those far reaches of space, in a lab on a small space station, these two A gametes are placed in a receptacle on a bench, side by side, as yet unjoined, but preserved by some method to keep them viable. We already more or less possess the technology to do this, so this is something that could literally have happened.

            If these A gametes are joined on that space station and grow into a full and normal human being there, we have established already that you should think of that human being on that space station as you, in the same way you would think of the human being living in France right now as you if your parents had moved you to France when you were five. In other words, in imaging those gametes brought out to that space station all those years ago and being joined and the resulting conceptus growing into a human being (in a surrogate mother perhaps, or maybe even re-implanted in your actual mother, or in some as-yet uncreated machine), when you imagine the present moment in this alternate reality, you should be imagining yourself there right now. You should not be imaging yourself nowhere at all, as you would be if those gametes were never joined. This is, at least, what would be in keeping with most people’s beliefs, i.e., the standard belief about coming into existence.

            Now, look again at those A gametes on the space station before they are joined. They are just two gametes in a dish on a bench. Here’s where the new twist to the thought experiment begins: right next to the two unjoined A gametes on that bench are a set of gametes qualitatively identical[3] to the A gametes. Call these the B gametes, sperm B and ovum B. These B gametes are qualitatively identical in every single possible way to the A gametes, the ones that produced you. Genetically identical, of course, but also identical to whatever extent possible in total physical structure, right down to the last atom, even the last electron or quark. Don’t get too concerned with the details of the subatomic physics here; we’ll just say identical to whatever extent possible, in other words, to whatever extent it even makes sense to say identical.

You might be wondering, where did these B gametes come from? How was an independent set of gametes created that were qualitatively identical to the gametes that produced you? I’ll discuss ways this might have happened later, but for our purposes at the moment it doesn’t matter yet. It is enough to note the obvious fact that for any physical object in our universe, an exact copy of it could exist.

Now, what if out on this space station the A gametes were allowed to join with each other and the B gametes allowed to join with each other, and both conceptuses allowed to come to term and grow up into human beings on that space station and these human being lived to the present? You probably believe that you would exist in that case as the person who grew from the A gametes (the A person), and another person would exist as the person who grew from the B gametes (the B person), who would be in most practical respects an identical twin, both of you out on that space station right now. You should believe this, if you want to be consistent with your other beliefs. And you should of course believe that you would come into existence if the A gametes were joined and the B gametes not joined. There is no reason to believe that the existence and/or joining of the B gametes or any other set of gametes that are not the A gametes has any effect whatsoever on whether or not you exist. We’ve already tacitly established this. The only thing that affects you coming into existence is the A gametes.

It follows from this then that if just the B gametes were joined and not the A gametes, then this other person, the B person, would come into existence and you would not. If you are tempted to say that you would be the B person in that case, that it would be proper or acceptable to imagine yourself existing there now as the result of the B gametes rather than not existing at all, then I’d like to draw your attention to what the B person would think about that, if you both existed right now. They could just as easily claim that they would be the one to come into existence, and not you, if the A gametes had been joined but not the B gametes. (If you need more convincing on this point, I provide a detailed argument in the appendix.)

            Now let’s get down to the point of all this apparatus. The action heats up: Imagine that a scientist walks into the room on the space station and stands right between the two sets of gametes, A gametes on the left and B gametes on the right. She picks up both sets, one in each hand. She is going to select one set of gametes to keep and one set to destroy. The ones she keeps will be placed in another receptacle, which has been between the first two all along. The ones she destroys will be placed in a machine that destroys them. She chooses to keep the A gametes, and destroy the B gametes. The A gametes safely in the new receptacle on the bench, she walks away to take care of other scientist business.

A while later, a doctor walks into the room, and takes the receptacle that now contains the A gametes through an air lock and onto a transport ship heading for earth, while the scientist remains on the space station. This doctor doesn’t even know that there were originally two sets of gametes, and that the scientist chose one and destroyed the other. He just picked up that receptacle as instructed to bring it back to earth. When he arrives back on earth, he joins the gametes in a lab to create a zygote, and he goes to see your mother with the zygote. She also has no knowledge that there were ever two sets of gametes. She’s just happy to be having a child, and remembers gametes being extracted from her and your father before. The doctor implants the zygote and nine months later a child is born, your mother and father raise this child, and it lives a full and normal life. This is person A, and we’ll call the whole scenario universe A.

Who is this person A in universe A? Is it you? Of course he/she is. We’ve established that you are the result of the A gametes wherever and whenever in the universe they go, including out into space and then back to earth. So we can amend what we said just now to “nine months later you are born, your mother and father raise you, and you live a full and normal life.” That is the proper way to imagine this scenario.

And here is an essential part of the thought experiment: in order to make it especially vivid, imagine that these are the actual circumstances under which you came into existence, that this is the actual story of your conception that led to exactly the life you’ve actually lived up to the present, the same in every detail. Since none of us remember our conception or gestation period or indeed even the first few years of our life after birth, this should be easy. So, from your perspective, the A universe is the actual universe we live in now. This will not be true for probably everyone who will ever read this, but it has no effect on the pertinence of the thought experiment, since it could happen to someone, and this makes it relevant to all of us.

With this in mind, imagine this situation again from the beginning, with one small change to it. You have probably guessed it already: the scientist chooses the B gametes to keep, and destroys the A gametes. Everything up to the point of the choice of the gametes is the same as in the previous scenario, in the A universe; every movement and thought of the scientist, everything. And again, after those movements where the choice is made, everything else is the same, to the maximum extent possible. The B gametes are set down in the new receptacle in exactly the same way the A gametes were, and sit there in exactly the same configuration (more accurately, configurations through time) as the A gametes did. The scientist steps away from the bench and goes off to do exactly the same thing she did in the previous scenario. The doctor walks in and takes the gametes onto a space ship, travels the great distance back to earth doing exactly the same thing each moment he did in the A universe, creates the zygote from them upon returning to earth, and brings the embryo to your mother on earth. Remember that neither the doctor nor your mother know there were two sets of gametes and that a choice was made, so it is very easy to imagine all of their movements and thoughts being truly (numerically) identical in the two situations, from start to finish, and therefore all the movements through space and time of the two sets of gametes being identical in their respective universes.

So this zygote B is implanted in your mother, and a child is born, person B. This is universe B. Your parents raise person B in the same way as they raised you, down to the last detail. This includes, of course, giving him or her your name. Further, person B now proceeds to live a life that is identical to person A’s in every possible way. In other words, as stipulated, identical to the one you actually have lived and will live until you die, and identical down to every atom and quark, however small you think it is reasonable to go. The point is that all movements of matter through space and time are the same in universe A and B from the point in time right after the scientist made the choice up to the present.[4] If this is too generous a possibility for you to entertain, you can limit the identity to everything that happened within the atmosphere of earth. The point of the great distance of the space station, and the tininess of the difference at that great distance, is to make this more plausible. What happens on earth is all that really matters for the thought experiment.

And of course, person B is not you. Everything we’ve said so far makes person B not you. (Again, see the appendix if you need further convincing of this.) Person B lives a life identical to yours, right down to the last atom, from the very beginning of that life up to the present, and into the future until death, but person B is not you. Person B is your perfect doppelgänger, another person living your exact life in your stead, from beginning to end. And in universe B, you don’t exist at all, anywhere, ever. When you think of this situation, you should image yourself nowhere in it, just as you do when imagining all the other situations where the A gametes never join.

I call this the perfect doppelgänger thought experiment. I’ll use the abbreviation PD to refer to this thought experiment hereafter.

Some people might object to these claims of physical identity between the two universes, even just on earth. Rather than take up time with these objections here, I’ll discuss them in an appendix. Part of the power of this story is just in imagining it, and this is undoubtedly possible to do. But I’m convinced that it is actually possible to attain something that for practical purposes is physical identity on earth between the two universes, for everything that happens on earth in universe B to match everything that has actually happened on earth in our universe, universe A. If you need to see the full argument for this, please do go to the appendix.[5]

So let’s think about what having a perfect doppelgänger would mean. Imagine your entire life being lived by someone else, this perfect doppelgänger of you, exactly as yours has been lived in every possible physical domain, and you never existing. First off, it is clear that this would have made not a bit of difference to anyone else. Your mother would have given the exact same love to this other person as she gave to you. No one who ever talked to you would have known what they were missing (or what they gained by knowing person B).[6] So the reality is that no one actually cares that you specifically exist, not even your own mother. They just care that someone of your exact physical makeup exists. That should be ego-deflating in several senses of the word. The only person it would matter to is you, and you don’t exist for it to matter to. And yet, to you, at this moment in this universe, from your vantage point of actually existing, this matters quite a lot. You can imagine not ever existing, and it’s something you really don’t want to have been the case. (For most people; my heart goes out to the depressives who do not feel this way.)

            It is especially instructive to imagine this being the case, right now, at this moment. Here we return to the spirit of the first version of the thought experiment: just consider yourself at this moment, whatever you are doing, then in your imagination delete yourself from the situation, and then put an exactly identical human being in your place, occupying all the same space as you. You don’t exist, but everyone else who exists right now does, and someone else exactly like you in every way is reading this book, or taking a moment to look up and glance out the window at a tree. Just look at that tree, or some other object, for a few moments, and calm your mind and meditate on it, and imagine not existing, not being here to look at that object, and then imagine that there is someone else, exactly like you in every way, here at this moment instead, occupying the space your body is now, looking at that object and having this exact same experience, instead of you, with all the rest of the world or universe being identical. Do it now, just for a moment.

            I like to put myself in the perfect doppelgänger state of mind at random moments day to day. Just walking down the street (I live in Tokyo, so this is much more than an outdated cliché for me), or shooting baskets, or shopping, thinking about something else, anything else, and in my imagination I make myself disappear completely, as though I had never existed, and place another identical human being in my place, walking the exact same path or making the exact same rebound in the exact same way and having the exact same thoughts.

Or even more vividly, talking with someone, looking in their eyes, and imagining an alternate universe where this person, this very same person, is having this very same conversation and experience, but not with me, not looking into my eyes, but with someone else, looking into someone else’s eyes, with someone else looking back at them, but no detail of the physical universe being different. I simply don’t exist, anywhere.

You can flip the roles as well, and imagine that other person being a perfect doppelgänger instead, that you could be in a qualitatively identical situation, looking into their eyes but not “seeing” the person you are seeing now, but a different person. Try it next time you talk to someone face to face. “Behind” those eyes, in the “caverns of their brain”, is a different person, the consciousness that is regarding you right now just not existing. This person who is looking at you now would not be looking at you in this alternate situation, but someone else would be, even though this alternate situation would be qualitatively physically identical in every way. This is a powerful thing to do with someone you are very close to and see often, someone you love deeply, like a partner or close friend, just imagining that you had had an exactly identical relationship up until now with a qualitatively identical person who was not the person you knew, but someone else. All those moments you were looking into this person’s eyes, in this counterfactual situation it was a different person looking back at you.[7]

I did this recently with Paul McCartney, watching A Hard Days’ Night for the first time. I just looked into that young fellow’s eyes there on that screen, and imagined the poor Paul McCartney we know never having existed, and another fellow being him instead, cracking all those jokes, writing all those songs, coming to live all of that rich and incredible life. To really hold onto the deep intuitive puzzle about existence I’m trying to get at with PD, it’s helpful to have these sorts of flights of imagination in many iterations over time, in many different scenarios, to really live with the idea and let it sink in. I recommend carrying it around with you for a while.

2.4 Content and Existence


As I indicated before, the primary lesson to draw from PD is this: it defines exactly what “I exist” actually means when a person says it. In other words, it defines what thing people are referring to when they say “I exist”. We could formulate it like this:

“I exist”, for any person, refers to the sole difference between universe A and universe B.

According to PD, we could have a region in space (within the atmosphere of earth) and a stretch of time (the length of a human lifetime) which was physically identical between two possibilities, right down to the atoms, and yet in one you exist and in the other you don’t. That one thing that is different, that one thing that obtains in universe A but not universe B, is what you mean when you say “I exist”. In other words, that one difference is the referent of “I exist”, what it is you are pointing to. It is the object of discussion when we talk about existence. PD isolates precisely what we are talking about when we say “I exist” from any other factors we might think we’re talking about.

Most specifically and usefully, what PD isolates your existence from is the content of your life and mind: memories, desires, intentions, likes, dislikes, loves, hates, hopes, dreams, anxieties, beliefs, aptitudes, skills, self-conception, and all the rest. The entirety of the content of my mind, down to every last detail, could exist even if I didn’t exist. It could exist in someone else. And so, when I say “I exist” I must mean something different from the content of my life.

The distinction between personal existence or “I exist” and content is one of the foundational points of this book, and I will return to it many times.


I’m going to call this existence isolated from content “personal existence”. Up until now I’ve called it just existence or “your existence”, or I’ve been using “I exist” as a single noun in quotes to hold it together. I’ll continue using those terms, but I’ll add this term “personal existence” to them. Though I find it somewhat inelegant, it is useful because it is unambiguous, rigid and descriptive. I’ll say more about this term in the next section.

There is a sense in which you already knew about this distinction between content and your existence without the apparatus of PD, even if you never articulated it. Imagining having moved to the south of France in the distant past of your life, or any other alternate life for yourself, has this same effect of isolating content from personal existence as separate phenomena as PD does. When we imagine a different life for ourselves, we are imagining the same personal existence with different content.[8] Or at least, most of us are. But PD makes this isolation of personal existence stark in a way that this more everyday imagining does not, because it keeps content constant, which is the thing we already have a clear definition of, while changing the personal existence, which is the thing that has been hidden to most of us. By changing it, moving it around as it were, we can thereby see it.

This concept of personal existence can seem simple from some perspectives, but as I’ve indicated already, I think it is quite deep and profound when seen from other perspectives. Once you see it, this existence isolated from content pops out at you from the background, as something mysterious that has always been there but that you could never quite put your finger on. At least that’s how experienced it when I first saw it. PD defines the content of that intuition about our own existence that comes to some of us in fleeting moments, that seems inexpressible and ungraspable. Understanding what my existence consists of is making clear and prosaic what has previously been a deep mystery.

Like PD, it is an idea you should sit with and chew on for a while. Practice applying it in various situations throughout your everyday life.

2.5 The Body-Tracing Criteria

Let me finally suggest a way that you use this concept of your own existence, i.e., your personal existence. This is the culmination of what I began in section 1 of this chapter.

We inhabit a whole universe of time and space. In this universe, there is the present moment, and the location you are in now. There is a lot of time that is past in this universe. There is (presumably) a lot of time that is future. And there are a lot of other places. You sometimes imagine these different times and places, and in some of them you imagine your personal existence obtaining, and in some of them you imagine it not obtaining. In other words, in some of them you imagine yourself existing when you imagine them, and in some of them you imagine yourself not existing.

Further, there are other possibilities for this universe. These are not actual, they are only what could have happened. One example is the possibility that your family could have moved to France when you were five. They didn’t, but they could have. Another is the possibility that your parents never met. Or that you hadn’t gotten that one job you love. And so you think about more than just the questions above. When you imagine these alternate situations, in some of them you imagine your personal existence obtaining, and in some of them you imagine it not obtaining. In other words, in some of them you imagine yourself existing, and in some of them you imagine yourself not existing.

Most of us have strong beliefs about which times and places and alternate situations we should and should not imagine ourselves existing in. And most of us use an unconscious rule of thumb to answer them. I call this rule of thumb the body-tracing criteria. In your imagination, you trace the human body you are now back and forth through space and time and into alternate possibilities that did not actually come to be, and wherever you find that human body, you place your personal existence there. Or, to put it another way, you imagine yourself existing there. Your personal existence goes wherever that human body goes. This is true no matter what content that body ends up having due to variable influences from the environment. If it goes to France and learns French instead of English, then it is you that learns French and not English, there in France, and you that is there now, speaking French. That human body is not someone else there, speaking French, the way that all the other people there now are someone else there, not you, speaking French. You do not not exist in that situation.

And in situations where that human body is not, either before its conception, after the death of the body, or in alternate situations where that human body never comes to be, so too your personal existence is not. You do not exist in those situations. In other words, your rule, the body-tracing criteria, tells you that you should not imagine yourself existing in those situations.

I think this is a correct description of what we actually do imagine when we are imagining times and places that are not the actual present. This belief has a central place in the argument for my new view, so I will return to it often. It is one of the two main pillars of that new view.

You may see a problem with this story though. This description also matches exactly how people would talk if they really were just talking about a particular human body when they say “I exist”. How do I know they are not? How do I know they are rather talking about this other thing or concept I’ve isolated and named, this so-called personal existence? The short answer is this: consider just how amazed people are at the long odds against them coming into existence. How could they feel that way if they were just talking about a particular human body? I will claim that they couldn’t. I will flesh this point out in the long answer to this question in the next section.

This completes the central argument of Chapter 1. The next section consists of some clarifications and tightening up of the concepts, some answers to objections, and an interesting problem that pops out of PD. You may already be 100% on board with me and judge some of these to be unnecessary to your understanding; I leave that up to you. The essential thread of the argument picks up in Chapter 2, where I take this concept of personal existence and see how it matches up with our core belief in the gamete-dependence claim.

  1. Objections and Clarifications


3.1 Just a Human Being? And Other Objections


So how do I know that when people say “I exist” they aren’t just referring to a particular human being that exists, just as they might any other object? How do I know they really have in mind this metaphysical object I’ve isolated from content here? This is a tricky question to answer, because I will be claiming to get into other people’s minds, to know more about what they actually believe than they themselves do. I put this particular discussion off until now in the hope that I could get you to see and accept the concept of personal existence even if you would otherwise be resistant to it or to my methods of bringing it out into the open. I hoped that once you saw it you would agree that it really is what you are referring to when you say “I exist”, at least some of the time, even if before you thought it wasn’t, and that after seeing the concept you would then agree with me that the way this “I exist” behaves in your intuitive or subconscious sense of it is the way I’ve described. Most importantly, that it is the absence of this personal existence that you are thinking of when you think of not existing. By seeing these things, I thought you might find that your objections had disappeared with no direct attack on them. This is my hope for everyone, and it would be easiest if this is what happened to you. But I do have another argument to offer to convince you that you are talking about personal existence, that this is what you really have in mind, when you say “I exist”, and not your human body.

Recall some of the things Richard Dawkins said about coming into existence in the quote I gave in earlier:

We are going to die, and that makes us the lucky ones… The potential people who could have been here in my place but who in fact will never see the light of day outnumber the sand grains of Arabia… The set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here… The instant at which a particular spermatozoon penetrated a particular egg was, in your private hindsight, a moment of dizzying singularity… Your parents had to meet, and the conception of each was as improbable as your own. And so on back, through your four grandparents and eight great grandparents, back to where it doesn’t bear thinking about… Not just Napoleon but the humblest medieval peasant had only to sneeze in order to affect something which changed something else which, after a long chain reaction, led to the consequence that one of your would-be ancestors failed to be your ancestor and became somebody else’s instead… The thread of historical events by which our existence hangs is wincingly tenuous.

What these quotes demonstrate is something that most people feel when considering the odds of their own existence, and in fact the reason people tend to bring it up in the first place: sheer stupefied amazement that it happened at all, and great concern that it should have happened. And this is what tips their hand that they are talking about this personal existence I’ve taken pains to clarify here, and not something so prosaic as just the existence of a particular human body, when they talk about their own existence, or when they say “I exist”. It would not be possible to be amazed at this, or to be concerned that it should happen, if you weren’t talking about your own personal existence.

If one were talking just about the fact that a particular human body came to be out of the huge number of possible ones that could have come to be—the number of possible DNA combinations, for example—one would have no reason to be amazed by it. No more reason than being amazed if you were to pick a random 20-digit number out of all possible 20-digit numbers. One had to be picked. In fact, I will do it right now, using a random number generator on the Internet. My number was 55,419,245,515,621,404,581. Isn’t that amazing? Do you realize that the odds against that exact number coming up were 1 in over 55 quintillion? That’s like counting to 55 trillion…one million times. If you were to pick one random twenty-digit number every second, discarding each one as a possibility after it was picked, it would take you over 1.4 trillion years to be certain of getting this one. That’s 100 times longer than all of the time that has elapsed since the big bang. And yet that’s the one that came up on my first try! Astounding![9]

No one is astounded by this. And the same is true for any particular human sequence of DNA that comes into existence. If a man and woman have sex and conceive a child, that child will have to have some human sequence of DNA. It only becomes amazing to a particular person when they consider that it was their own personal existence that came into being, against the amazing odds that it wouldn’t. In other words, that that sequence of DNA brought into being that (your) personal existence. Dawkins’ astonishment reveals that this, his (and your) own personal existence, is in fact what he is talking about coming into being, and not a human body, when he is talking about existence in his quote.

This then is our great concern: that this personal existence come to be, not that a particular human being come to be.

Now, Dawkins might claim that he is only talking about his human body. That is probably what he thought he was talking about when he wrote that. Perhaps if he read my discussion so far, he would realize that he wasn’t. But even if, after all my discussion so far, he still insisted he was talking only about a particular human body, I would simply consider him mistaken. I’ll say it again: it is not possible to be amazed at the long odds against you coming into existence unless you are talking about personal existence.

To be perfectly clear about what I mean in this case specifically: my claim is that people often allow personal existence into their ontology even if they disclaim it vehemently with their words. (Ontology: a theory or belief about what exists and what does not exist.) They often surreptitiously substitute it as the object of their discussion when they talk about existence, even if they themselves are unaware that they’ve done this, and even if they insist to the ends of the earth that they don’t believe in such things, and are only talking about a particular human being when they talk about existence. This can be true for even very intelligent and well-meaning and diligent and perceptive people who have worked very hard on the problem. And I am certain that there is no other way to be amazed that you exist against such long odds than by talking about personal existence, the exact concept of personal existence I have labored so much to bring to light, whether you admit to it or not. There is nothing else you could be talking about.

            You might object, it’s not just a concern that a human body should come to be, it’s a concern that my human body should come to be. But it is still just a concern about a human body. My reply is that once you add that “my”, you have admitted personal existence into your ontology. You can’t pick out a particular human body with “my” unless you do.

            So what appears, in Dawkins’ quote, to be a straightforward recitation of simple facts about the coming into being of a particular human being, is actually surreptitiously entirely about this oddly metaphysical idea, this personal existence. And this is so not just for Dawkins, but for everyone who thinks similarly. I’ve just used Dawkins as a mouthpiece for the common belief.

Here’s another way of looking at it: imagine a computer being amazed at the long odds against its own coming into existence. What would we have to attribute to that computer in order for it to make sense that it is amazed at the long odds against it itself, and no other, coming into existence? We would have to attribute to it a personal existence, the type of “I exist” we ourselves have, and that this is what it was talking about being amazed at coming to be, not just the particular configuration of physical parts that make it. And we would have to imagine that the computer would assume that its personal existence would be absent, completely absent from the universe, had something been different about the physical makeup of its construction when it was made. Had its construction been different—different materials or different configuration—it would believe that that object would have been someone else, a different personal existence, not the one it itself was so lucky to have come into being. Otherwise there would be no luck or extremely long odds. These beliefs would be required for it to be amazed. A further corollary to this, though not essential just yet, is that the computer would also have to imagine that it would continue to exist, be the same personal existence, through some changes in its content (software, data) over time.

If, after all of this, you still feel resistant to this claim, may I suggest that you may actually be making too much of my concept of personal existence. Maybe you are afraid I am reifying this personal existence, claiming that this thing that is separate from content is an actual real thing itself. (Reify: to make something into a concrete, real thing.) I do not take this reification to be an essential part of my theory. You can think of personal existence as just a concept if you like. For reasons that will become clearer in Chapter 3, I don’t think it is essential that we decide whether it is a concept or an actual thing. Whether we call it an illusion or a hallucination or reality doesn’t matter that much. So I would entreat you to not deny it simply because you fear accepting it would force you to accept too much. Look within yourself and see if this is at least the way you experience your own existence, if you can at least make this distinction conceptually. Feel free to call it an illusion after that if you like. I’ll speak more to you on that point in Chapter 3.

Alternately, perhaps you actually do see it already but don’t realize you see it. Maybe you had been seeing it all along, even before reading any of this, and now you think I’m pointing you to something different. Or perhaps all of my words have made you think it must be something more complicated or esoteric than the thing you now have in mind. But you might have it already. It is a pre-philosophical intuition; complex words don’t mean it is a complex concept. The complex words are just meant to get you to see the simple concept. You may already be seeing the simple concept and not realize you are seeing it, not realizing this basic thing you understand is the thing all of these complex words were meant to point out to you.

And there is another point. One reason this distinction between content and existence is not made in a great many discussions of existence—much to the detriment of the clarity of those discussions—is that many people would say that the distinction can’t be made. It is a common belief among materialists that there can be no consciousness without content. I agree with this belief. There is no “I exist” without content, and more precisely physically embodied content. I do not believe that this “I exist” is an actual object or thing separate from matter. Further, a featureless Cartesian ego—a pure subjective existence without any content to it—is not possible. It’s not even really conceivable; we may think we can conceive of it, but when we try to imagine it or think we are imagining it we are not really imagining it. We are still imagining some content, even if it is a much smaller amount than we have in our lives now. But content and “I exist”, or who exists, still refer to two different things, even if a particular personal existence requires content of some sort to exist at all. This is true no matter what we think the ontology—the reality—of this personal existence is. Saying “I exist” isn’t just saying that a certain organism-embodied content obtains at a certain time and place. Saying “I exist” is adding something more to those facts about content. It is saying that something has obtained in a region of space and time that might not have obtained even if all the physical facts of that region of space and time were the same.

            And this is everything I have to throw at you to convince you of my view on personal existence until Chapter 3. Everything from now until then assumes we are in agreement on the view of personal existence I have laid out here. I leave it up to those who may still not be in agreement, who may still be holding onto the alternate view of existence I hinted at in the introduction, whether they want to go straight to Chapter 3 now.

3.2 A Problem for Materialism

One of the consequences of PD that is quite striking is that it seems to cause a problem for materialism. And since a great many people who profess the standard belief (the gamete-dependence claim) about coming into existence that leads us to conclude as we do about PD are materialists (as the Dawkins quote demonstrates), this is an inconsistency in their beliefs.

Recall that materialism is the belief that all that exists is part of the material world. A complete description of the location and trajectory of every atom and subatomic particle, every force and field, everything that could in principle be measured or detected under some circumstances, would just be a complete description of everything. There would be nothing more to describe after all of that, no gods or souls or ghosts or heaven or hell outside of the material universe. And yet, if we made such a complete description of universe A and then universe B, at least within the atmosphere of earth, for all the time of the existence of the earth, then the complete physical description of both would be identical. Think about that: the earth in universe A and B, from the beginning of time to the end of it, is identical in every physical detail. During just the time period we’re concerned with, in both universes a ship leaves with two gametes, and then some time later returns with two gametes, and in both cases every one of the atoms and subatomic particles are in identical states through time. Absolutely identical, not a single bit of physical difference. But according to PD, there is a difference anyway. In one of them you exist, in one of them you don’t. That is a real difference. It is something we can point to in those two universes and being different between them. The only thing we can point to in fact. And thus materialism is not true. Something exists or does not exist which would not be specified by a physical description; a physical description would not specify whether it exists. A physicial description would be an incomplete description.

Thomas Nagel makes a similar point without using the apparatus of two physically identical universes:

Consider everything that can be said about the world… This will include the descriptions of all its physical contents and their states, activities, and attributes. It will also include a description of all the persons in the world and their histories, memories, thoughts, sensations, perceptions, intentions, and so forth. I can thus describe…the entire world and everything that is happening in it—and this will include a description of Thomas Nagel and what he is thinking and feeling. But there seems to be one thing I cannot say in this fashion—namely, which of the various persons in the world I am. Even when everything that can be said in the specified manner has been said, and the world has in a sense been completely described, there seems to remain one fact which has not been expressed, and that is the fact that I am Thomas Nagel.[10]

            The way that PD troubles materialism is one of the reasons that, as I said in the introduction, early in my quest for answers to my questions about my own existence, I thought that PD showed the existence of the soul. In fact, that was originally my purpose for PD, to isolate what I thought in the universe must be a soul. If a complete physical description of a world is not a complete description of everything in that world—namely, it is missing the facts of whether or not I am in it and who I am in it—then there must be something else in that world that is not physical. And what is missing in that description bears a very close resemblance to what we have called as soul.

But as you know, I don’t believe that anymore. There is a better way to solve this apparent problem with materialism than discarding belief in materialism. (And, as I hinted at in the introduction, a soul doesn’t solve this problem anyway.) So we’ll just mark this off as one problem with the standard belief. We’ll come to more such problems in Chapter 2.

3.3 Terminological Clarifications


Finally, let me explain more about my choice of the term “personal existence”. As I said earlier, there are a number of terms I’ve been using to name this thing I have just isolated. “I exist”, in quotes to hold it together, is one. I’ve also been calling it just “existence”. This is in line with our common usage in casual conversation. But “existence” alone is too vague; lots of things exist, so just the word “existence” doesn’t clearly refer to the thing I’m talking about out of context. So I’ve coined this more precise term too, personal existence. I find it a bit lumbering and cumbersome, and am jealous of some of the great philosophical terms of the past, like Dasein or Existenz[11], but personal existence has the advantage of being descriptive (it means “the existence of a person”), and being of clear descent from an existing common term in the philosophical discourse on this very same subject, “personal identity”. In this book I shall continue to use “I exist”, “existence”, and “personal existence” interchangeably.

Philosophers might wonder why I didn’t just use the term “personal identity”, since it is the term this discussion is usually cast in. I have reasons for this that are more relevant to those steeped in the field, so I’ll save my detailed explanation for Chapter 3, where I explain why I’ve chosen to focus on the term “existence” instead of the way these kinds of discussions are usually framed. Suffice it to say I think that our use of the term “identity” is part of the problem, part of what causes our muddle and talking past each other. It doesn’t clearly distinguish between content and existence. (The same is true of the term “self”, which I will also discuss in Chapter 3.)

There is one reason to avoid the word “identity” in these discussions that is relevant to everyone though. Think of the term “gender identity”, by now well-known to most of the general public. This is, among other things, your self-conception of your gender, male or female (or something else like “in between” or “fluid” or “none”). Such a socially and biologically constructed self-conception is a type of content of a mind or a person, which is the thing I want to isolate personal existence from. So to use “identity” would invite re-conflating the two ideas I’ve worked so hard to separate.

I started out Chapter 1 using the term “existence” without clearly defining it, until we got up to a precise clarification of what I meant by it with the term “personal existence”. But I’ve actually been using the term “person” pretty haphazardly as well. (Note that the “personal” in “personal existence” and “personal identity” actually means “of a person.” It doesn’t really mean “ownership”, as in “personal property”. I spent many years of my study of personal identity confused on this point.) I think mostly the word “person” can be used casually in normal conversation without much trouble. I was trying to ease into the argument as gradually and painlessly as possible, so I didn’t want to draw attention to it. But the word “person” is actually not precise enough. We should make a distinction between “person” and “human being”. Philosophers will already have docked me for not making this distinction yet. (But then, one could also claim that it would be begging the question to make it before completing PD and giving my analysis of it.) Anyway, I am making it now, and will stick with it from here on out.

“Human being” is a scientific term, just like “chimpanzee” or “dolphin” or “beetle”. It will be used to refer to a particular physical object, a particular individual animal of the species homo sapiens moving through space and time. Sometimes I will say “human being A” or “human being B” in reference to the entities introduced in PD as person A and person B. “Person” then becomes a more esoteric, metaphysical term, without as clearly agreed upon a definition. In general it has come to be used in philosophy and other disciplines as a term for any consciousness we might consider as countably singular, not just that of humans. We might include further considerations as well, less metaphysical and more practical, such as whether it should be accorded rights, and what rights it should be accorded. Intelligent life originating outside earth (i.e., space aliens) might be persons. A chimpanzee or dolphin might be a person. Probably a beetle is not. Artificial intelligence might attain personhood. These are all debated questions, and there is a political slant to the use of the word “person” for these non-human entities that I hope will not distract you; a different and completely neutral term could have functioned just as well. My inclination is to affirm all these “mights”, but that is not germane just yet. “Person” is necessarily more vaguely defined than “human being”, and therefore its usage will also at times be more by feel than by precise definition, but for my purposes it can be thought of as the entity that has a certain personal existence (although this is a somewhat circular definition). It can also be thought of as the internal view, the view “looking out” from an organism or AI, if you will (although this might be charged with begging the question). I will also continue using “person A” and “person B” in reference to PD, but from now the terms will be used more carefully.

[1] With apologies to everyone already standing outside the south of France right now. You’ll just have to think of your own counterfactuals to use as examples.

[2] It is an interesting side point to consider how people identify with these primitive antecedents to their current human body. People might say “when I was a zygote” or “when I was an embryo”—I’m certain I’ve unconsciously uttered these phrases at points in my life—yet not “when I was a pair of gametes.” This is probably due to number agreement: it seems strange to identify yourself with two separate objects. Moreover, people often identify with just the sperm, saying things like “I won the race to the ovum”. Why don’t people identify with the ovum instead? It would certainly make more sense to, since the ovum contains almost all of the actual matter your body started from. Perhaps some chauvinism there?

[3] There’s two different meanings for the word “identical”. Numerically identical means one and the same object. Everything is numerically identical just to itself. Whether numerical identity is retained across time or alternate possibilities is a philosophical question (i.e., whether this pencil is the same pencil as it was one second or one minute or one year ago, or would have been had it been sold to someone else). Qualitatively identical actually just means two separate objects that are similar in every possible way, or at least in every way relevant to the context. In other words, identical in qualities. Such objects can exist at the same time in the same universe. If I use just the term “identical”, as I do even in this paragraph, I mean “qualitatively identical”.

[4] In fact, right after the doctor leaves the space station on his ship, the space station falls into a black hole. Poor scientist.

[5] Briefly, the conceptual part of the argument (not relying on the actual details of physics) goes like this: If you are incredulous about the two universes matching atom for atom or quark for quark because of the indeterminacy down at those small sizes, then just pick some larger quantity of matter to match up. At some level, identity makes sense, and if it doesn’t make sense at smaller than that level then it doesn’t matter whether we say or think the two universes are identical at those levels anyway. I think it might make sense even at the level of atoms or quarks. But even if not, the level at which identity undoubtedly does make sense is still extremely small, small enough for all practical purposes. If you need to see the full argument for this, then please do go to the appendix.

[6] Of course, no one would even have “noticed” if a completely qualitatively different human being had existed instead of you either, but I think you get my point.

[7] This belies a prejudice for sighted people, I know. I’ll discuss this a little more in Chapter 4.

[8] An interesting thought is to imagine an alternate life for yourself, and then imagine an identical twin actually leading that alternate life in this universe we are in now, matching it atom for atom. An identical twin would be a perfect doppelgänger of your alternate life, and if he or she was someplace you’ve never been, could even be existing right now in the universe you inhabit.

[9] I’m quite pleased by the number I got. I got it by generating one digit at a time. There’s an awful lot of 5’s in it, and only 15% of the digits are over 5, when on average they will appear 40% of the time. Both of these are features that an intentionally selected series of digits would be less likely to have than a randomly generated one. Also, there are no 7’s at all, and this is far and away the most commonly selected digit when you ask someone to pick one randomly. And I’m glad that there was at least one zero, as this proves to you that I was using the generator correctly, calibrating it for digits 0 to 9, instead of a number from 1 to 9 or 1 to 10. All in all, I would say this a very fine example of a random number mocking our intuitions of what a random number should look like. What are the odds of that happening?

[10] The ellipses in this quote are the elision of Nagel’s technical term “token-reflexive expressions”, which I won’t explain here. It means something similar to a subject or an existence as I’ve been using the term, without the metaphysics.

[11] Even when I discover some German I can use I don’t get such elegance: the term “perfect doppelgänger” is also rather lumbering.


Chapter 2: Problems

What Caused You To Exist?

It isn’t easy to absorb the fact that I am contained in the world at all. It seems outlandish that the centerless universe, in all its spatiotemporal immensity, should have produced me, of all people—and produced me by producing Thomas Nagel. There was no such thing as me for ages, but with the formation of a particular physical organism at a particular place and time, suddenly there is me, for as long as the organism survives. In the objective flow of the cosmos this subjectively (to me!) stupendous event produces hardly a ripple. How can the existence of one member of one species have this remarkable consequence?

These questions may strike you as ridiculous even if you ask them about yourself, but I am trying to evoke a sharp intuitive puzzle and to convince you that there is something real in it, even if its verbal expression is faulty. There may be cases where a trick of language produces the illusion of a question where really none exists, but this is not one of them. We can feel the question apart from its verbal expression, and the difficulty is to pose it without turning it into something superficial, or inviting answers that may seem adequate to its verbal form but that don’t really meet the problem beneath the surface. In philosophy the question is never just what we shall say. We can reach that point only after considerable effort has been made to express and deal with inchoate perplexity. Amazement that the universe should have come to contain a being with the unique property of being me is a very primitive feeling.

Thomas Nagel, The View From Nowhere

  1. Introduction: What Is The Standard Belief Really About?


In Chapter 1 we learned what we are actually talking about when we say “I exist”. We are not saying just that a human body exists, at least some of the time. We are talking about something more esoteric, something harder to pin down, which I have called personal existence. Your personal existence is the thing that would be absent from the world if your perfect doppelgänger were living your life in your stead. The only thing that would be absent, in comparison to the actual world we inhabit now.

Understanding that this thing is what we are referring to or pointing to when we say “I exist” has great consequences for our understanding of the standard belief about coming into existence, the gamete-dependence claim. For the first time, we can see what this belief is really about, and why it amazes people so much when they take the time to look at it in detail (by considering the odds of coming into existence, for example):  It’s not just making the obviously true claim that a particular human body (yours) would not exist had a particular pair of gametes not joined. It is saying that that particular pair of gametes somehow brought your personal existence into being. In other words, some characteristics of those gametes that sets them apart from all of the other actual and possible gametes in the universe was responsible for bringing your personal existence and no other into being, while all the other actual and possible gametes in the universe did not bring or would not have brought your personal existence into being.

The question then becomes, what characteristics were responsible for bringing your personal existence into being—what characteristics of those gametes picked out your personal existence and no other—and how did they do it? When considering the long odds of coming into existence, people often focus on three factors: the odds of your DNA pattern coming to be from among all the possible DNA patterns, the odds of that one sperm “winning the prize” of fertilizing the ovum from among all the sperm that were there, and the odds of your parents meeting and copulating (at just the right time no less) from among all the people on the planet. So was it one or all of these factors that brought your personal existence into being? And if it was one or any of these things, then what is the connection between it or them and your personal existence? What is it about that characteristic that makes it be the thing or one of the things that brings your personal existence into being rather than another? You may see the answer intuitively already: there couldn’t possibly be any. How could any physical parameters distinguish between two different personal existences? We see this quite vividly in the perfect doppelgänger thought experiment, where nearly identical physical parameters (save for origin) still bring into being two different personal existences. There is nothing to logically or empirically link a particular personal existence up with any physical characteristics. In Chapter 2 we will look at this now obvious fact in detail.

There are objections to this line of reasoning that I won’t mention just yet so as not to muddy the waters for those who are really in tune with what I’m saying here. I’ll get to these objections in Chapter 3. But for the more incredulous among you, I’ll once again give you some hints about how I will be dealing with these objections when I get to them, by way of some reminders from Chapter 1. Remember that the paradoxes of the last paragraph only exist if we accept the view of personal existence I established in Chapter 1, the belief that you existed/will exist/would exist fully in the past and future of your human body and in alternate histories of your human body, and that you would not exist at all in any situations outside of those. In other words, that your personal existence is all-or-nothing. Remember that this all-or-nothing character of personal existence is a necessary part of the gamete-dependence claim, otherwise we would have not-moving-to-France-at-age-5 dependence claims and a practically infinite number of other life-event dependence claims. Anyone who believes in the gamete-dependence claim believes existence is all-or-nothing. However, in Chapter 3 I will show that believing your existence to be all-or-nothing is probably nothing more than a choice we make about how to conceive of ourselves (though it may be a choice that evolution has encouraged us to make). But for now I’m assuming that it is the way most people conceive of themselves.[1] It is definitely the way I conceive of myself, and I find I cannot do otherwise. And so the more philosophically rigorous way to conceive of Chapter 2 would be to say that this choice to conceive of ourselves this way has consequences that we cannot escape. The main consequence is that the gamete-dependence claim makes no sense, which is what I will shows in Chapter 2. And as I will show in Chapter 4 and 5, rejecting the gamete-dependence claim has consequences on our views about death, and this is revolutionary.

            But I have not cast Chapter 2 in these more careful “if you believe this, then this” terms. Chapter 2 assumes you believe as I have described in Chapter 1, because that chapter is really just a description of the intuitive pre-philosophical way a great many people think. Really, if you already believed as I described in Chapter 1 before I described it for you, Chapter 2 could have been your first chapter. You would have found the questions and eerie paradoxes I raise here about your existence to make sense. I would have liked to have started the book with Chapter 2 in fact. Some early readers have reported it to be more interesting and compelling, and easier to understand. But Chapter 1 was necessary for a couple of reasons. It hopefully brought more people on board with these beliefs, and for those it has not, at least it has made clear the assumptions that are underlying Chapter 2, setting clearer terms for a disagreement about it. (Other early readers, who hold the objections I mentioned above, simply thought I was making a fundamental mistake with Chapter 2.) Most importantly, for those who are on board with the views about existence I described in Part I, we can use the analysis and conceptual distinctions to help us be more than just amazed and confused by the paradoxes of Chapter 2. We can take the concepts and tools I developed in Part I to see what these paradoxes are really about, and actually make progress on them, rather than just leaving them in bafflement and wonderment. The most important way we will do that is what I have already mentioned: seeing that the gamete-dependence claim is really a claim that some physical factors have brought into being this metaphysical idea we have of one particular personal existence and no other. Considering the odds of existence has previously left us in bafflement and wonder (with no progress) precisely because we didn’t know that this was what we took it to be about. We hadn’t yet made this belief explicit.

[1] Galen Strawson agrees, even though his natural intuitive sense is otherwise and he argues at length against the way of conceiving of yourself I’m describing here (Strawson 2009 14-15). I will get to his views in Chapter 3.


This was the Introduction, Chapter 1, and the introduction to Chapter 2 of a book called The Odds of Existing: Why Death is not the End. A draft of the rest of the book has been completed and can be found below, but I am currently in the process of revising that draft on the basis of comments I’ve received on it. This Chapter 1 is the first stage of that revision. The revised Chapter 2 has not yet been completed, but it will contain much of what is currently called Part I in the first draft, so if you cannot wait for the revision you can go there now. Or you could go to Part III of the first draft, which is the start of the argument for my new belief and will I think remain quite similar in the final draft.

            The first draft uses a confusingly different naming and numbering system for the sections. They line up with what will be the second draft as follows:

  • The Prelude is roughly equal to Chapter 1: Foundations (what you just finished reading)
  • Part I contains a lot of what will be in Chapter 2: Problems
  • Part II has important similarities to what will be Chapter 3: Alternatives (mostly in the discussion of “the thing we want”), but the alternative view I will argue against that I’ve alluded to in Chapter 1 is missing, or at least is not explicitly named. I will rely heavily on Daniel Kolak’s conceptual distinction between Closed, Empty and Open Individualism to ground this discussion. (I already have been doing so in Chapter 1, just not naming it yet.) I didn’t discover Kolak’s work until after the first draft was completed, but of all the things I’ve learned since the first draft, this has had far and away the greatest impact on this book.
  • Parts III and IV will likely be retained in a very similar form for Chapters 4 and 5. These contain the ultimate arguments for materialist reincarnation, and could be read on their own, though different readers will have different objections or confusions that are preemptively answered or explained in Chapters 1-3. But truly excited/impatient readers could go directly there.

This is all very confusing at this stage I know, and I’m certainly not asking or expecting anyone to continue reading right now. I just want to make sure the map is there for anyone who really does want to.

You can also get a pdf of what you’ve read so far here:



Part I: Gamete Identity

1. Why Do You Exist, Rather Than Not?

2. Everything is What it is and Not Another Thing (The Butlerian/Indexical View)

3. Gamete Identity: Explanations and Necessary Conditions for Your Existence
a. The Current Beliefs: The Three Conditions of DNA, Gametes and Parentage
b. The Relationship Between the Three Condition
c. Inhering
d. Gamete Identity: The Three Conditions, Separately Considered
i. DNA
ii. Other Candidate Essential Properties of Gametes
iii. Parentage
iv. A Very Special Perfect Doppelgänger
v. Conclusions From Gamete Identity

4. The Original End to My Philosophizing: A Mysterious Non-Materialism

Part II: What Do We Want?

1. What Do We Really Want? Unattaching from the Content of Our Lives

2. What We Have Right Now: Defense of a Partial Cartesianism
a. The Actual Referent of “I Exist”
b. The Counter-Argument: You Are Only Imagining That You Exist
c. The Real Meaning of the Claim That We Don’t Exist

3. Transworld Material Transmigration (TMT)

4. What Else Can We Have?

A Solution

Part III: How To Reject The Gamete-Dependence Claim

1. A Gamete Sorites: Could Other Gametes Have Produced You?
a. Matter Sorites
b. Three Tangential Points
i. The Incoherence of Being Partly One Person and Partly Another
ii. Empty Questions
iii. The Hidden Arbitrariness of the Indexical/Butlerian View (A1-X)
c. A Spatial Sorites and Compossibility
d. Split-Brains
e. Identical Twins, Free Will, and Self As The “Driver” Of The Body
f. Split-Brains Solution to Compossibility in the Gamete Sorites

2. Could You Have Had Different DNA or Different Parents?
a. The First Argument: DNA is Information
b. The Second Argument: A DNA Sorites
c. Conclusions on DNA
d. Total Spatial Sorites: Other Parents

Part IV: Better Beliefs About Personal Existence

1. The Minimal Conclusion: If Things Had Gone Differently
a. The Minimal Conclusion
b. The Arguments Against the Gamete-Dependence Claim, Rehearsed
c. Truly Facing The Odds of Existence
d. Complications for the Minimal Conclusion

2. The Maximal Conclusion: At Last, We Get To Death
a. New Age Dreams
b. Series Persons and Materialist Reincarnation
c. Isn’t This Belief the Same as the No Self View?
d. Is the New Age Dream the Correct Belief After All?


Part V: Some Thoughts On Life The Universe And Everything

Rawls’ Original Position
Buddhism: No Self and Reincarnation
Meaning in a Material World
Why Not Believe In A Soul?
The Multiverse
What Are People?
The Beginning of Infinity
Would I Have Stood Against Nazi Tyrrany?
What Is It Like To Be A Deer?
David K. Lewis’ Counterparts
My View vs. Parfit’s
Parfit and the Buddha

Further Reading

Philosopher’s Introduction and Summary

Feedback on this essay is welcome. You can comment publicly at the end, or you can contact me directly here.

A pdf of this essay is available here.


 Part I: Gamete Identity

1. Why Do You Exist?


            Where did the B gametes in PD come from? I never specified that, because the truth is it doesn’t much matter. A human gamete doesn’t depend on its origin or its past to be a functioning gamete, i.e., a gamete that can produce a human being. It just depends on its structure in the present. And any pair of one sperm and one ovum made to viable human-gamete specifications can in principle join and they will produce a human being. It doesn’t matter how they were made. So the B gametes could have in principle come from anywhere.

But we might wonder how nonetheless. So here are some ways a pair of gametes identical to the A gametes could have been produced, or could be produced. First, they could have come from your own parents. Each of your parents could have produced another gamete just like the one they produced that brought you into existence, at any time in their life that they were producing gametes. For your mother this was a very short period: only when she was a fetus. For your father, if he does not die or become infertile prematurely, this time span stretches 70 years or more. These gametes identical to the A gametes could have been produced by your parents by tremendous coincidence, or by being induced by some heretofore undiscovered medical process. The tremendous coincidence truly would be a tremendous coincidence[16], but it is still 100% and unambiguously within the realm of possibility. Alternately, it seems to me that the B gametes could have been produced by a different man and woman than your parents, even if this man and woman were not twins or otherwise close kin to your parents. The odds are surely absurd (and mitochondrial DNA complicates this even further), but two genetically different people could in principle create identical gametes.

            Another possible method would be all of the matter just spontaneously coalescing into a functioning gamete that was qualitatively identical to one of the gametes that produced you. There is nothing in physics that makes this impossible, although again, it is ridiculously unlikely, Vast orders of magnitude more unlikely than even the Vast unlikelihood of two different human beings creating identical gametes. The important point is that even if an object that was exactly human-gamete structured came into being by pure chance, having come from no human being, it would still be a viable gamete that could produce a human being.

And so a gamete produced by people via a deliberate process would also be a viable gamete. Perhaps one day they can be 3D printed. I believe people are already 3D printing pieces of organic tissue. Alternately, I believe scientists are also attempting to create gametes out of living people’s bone marrow. It has not yet been successful, but according to these scientists in theory it should work.

            Any of these artificial processes could produce a viable gamete, and consequently a new human being. There is no reason to think such a human being would be any different than one produced in the usual way. And so, any of these methods could have produced a pair of B gametes, and the B person. And if you had been created from any these artificial processes, we would be calling those artificially created gametes the A gametes.

For PD, it doesn’t matter how the B gametes came to be because the only thing that matters for PD is that the B gametes don’t produce you, but instead produce someone else, and this is true no matter how they came to be, since they are by definition any set of gametes qualitatively identical to the A gametes that aren’t the A gametes. If a pair of gametes did come into existence in exactly the same way as the A gametes, then that pair of gametes would be the A gametes. At this point, you may be wondering, well, what does that mean, “exactly the same way”? Exactly how similar would the process have to be to be exactly the same way? What factors of similarity or sameness matter? These are the right question to be asking. They’re the questions we’re going to explore in detail next and in Part III, that will lead us most directly to my conclusions.

You could ask questions in the same spirit as these questions in a slightly different way. For example, of all the possible gametes identical to yours that could have come to be, why was it necessary that they be produced in exactly the way the A gametes were in order to be gametes to bring you into existence? Why were those facts of method of production the determining factor in making them produce you, rather than (like the B gametes) someone else? What was it about that method of production? These are also good questions. Wondering such things is a good start at feeling the problem. But I before I address either of these sets of questions, I have a different angle I want to explore, a series of questions in a hierarchy, from most local to most broad.

We can drop the naming convention of A and B gametes. Objectively, there are no A and B gametes, just two pairs of identical gametes. If what we’re calling the B gametes were joined, then the resulting person would, on the convention we’re using, call the gametes that produced him or her the A gametes. And so without the names, they are just identical pairs of gametes. And there could be more than two pairs. From any or all of the production methods mentioned above, copies of these gametes could be produced. Perhaps 3D printing is the easiest to conceptualize. We could set any number of 3D printers to the task of printing up (out?) gametes identical to the ones that produced you, for any length of time. Millions, billions, quintillions of printers on innumerable planets printing up tens or hundreds of millions, billions, or quintillions of gametes every 24 hours, for billions of years. We could use up all the matter in the universe to create these gametes (maybe save some for enough stars to produce some heat), even breaking down printers into their constituent matter to be used to create gametes by other printers, until all there was left was one printer using the final bit of matter to produce the last few quintillion gametes.

If the universe is infinitely large and contains an infinite amount of matter, then an infinite number of gametes could be produced. If it lasts for an infinitely long time, then here too an infinite number could be produced, assuming each gamete lasts only a finite amount of time and the matter is then broken down to create another gamete. If you think this recycling raises questions about whether the new gametes would really produce a different person than the old gametes would have, then you are once again asking the right questions.

So this is the limit of possibility. But let’s forget about method of production now and just consider a mass of gametes coming into existence by any method of production, perhaps a combination of all of these. And lets focus on just one type of gamete as well. I’ll choose the ovum, to avoid the possible confusion about DS. DS aside, sperm would be a better choice for this exercise, because it is so much smaller and thus many more of them could be made, and is also usually the gamete variable people think of when they ask these questions about coming into existence, perhaps somewhat chauvinistically. So you can think of either, but I’ll be talking about ova.

Let’s just stumble in our mind upon a huge number of ova that happen to have the same genetic configuration as the ovum that produced you. We don’t know where they came from. The number can be any unimaginably large number you want, a quintillion, all the matter in the matter in the universe, infinite, whatever. The important point is this: of this quintillion or infinite number of identical ova, either one of them would be the one that would produce you, or none of them would. And by this I mean of course that either a) one of them would be the one that would produce you under the right circumstances, for example joining with the right sperm if you don’t believe in DS, or b) none of them would under any circumstances. But it is easier to remember the question when stated simply: either one of those ova would produce you, or none of them would. What would cause one or the other these facts to be the case? One of the two must be the case. These two possibilities are exhaustive of all possibilities.

The reason this works for even an infinite number of identical ova can be seen from an analogy to numbers. Of an infinite number of numbers, it is not true that one of them must be “2”. This can be demonstrated most simply by considering just the set of odd numbers, 1, 3, 5, 7, 9… But it is true of many other infinite sets as well, an infinite number in fact. So, of an infinite number of identical ova, it is not true that one of them must produce you. There could be an infinite number of identical ova in which none of them would produce you, and there could be an infinite number of identical ova in which one of them produces you. What would cause this fact to be one way rather than the other?

So that is one question. It is more meta than is usually asked, but it is important. Here is another question, the direct question more likely to be asked: If there is an ovum in there that produces you, what is it about it that would make it be the one that produced you?

This is the question people think they have an answer to. Speaking of both gametes, these factors might include: they came from my parents, they were produced at the time they were produced, or they were produced in the location they were produced. People also usually include the exact set of DNA they have as a factor. The gametes that produced me did so because they had that set of DNA. But here we are talking about a set of a large number of gametes that all have the same DNA, so this could not be stated as a factor in answering the question posed in this particular case.

But none of these is really an answer. We can just ask, why were those the determining factors? We’ll look more closely at this supposed answer in section 3 below and in Part III, but for now let’s get focus on the broader questions, and the intuition I’m trying to elicit with them. (Again, I’ll address the indexical answer to these questions in the next section.)

So we proceed with the questions assuming the gamete-dependence claim is true. So far we have two (I list them in the opposite order to the order I gave them in above, because this is the proper order for the hierarchy I’m using):

1)         Of an infinite set of ova, if one of them produces you (under the right circumstances), why does that one produce you and no other?

2)         Of an infinite set of ova, either one of them will produce you (under the right circumstances) or none of them will. What would cause one or the other of those to be the case?

The next question from here is, why should it be the case that in this universe any ova should be one that produced you (under the right circumstances)? Why, in other words, is it not the case that no matter what happened in this universe, you would not exist? It is easy to conceive of this being the case. You can conceive of the earth or even the universe populated with people or other conscious organisms, and you can conceive of none of them being you. If you believe the gamete-dependence claim, then this was a very real possibility for you. In fact, it was by far the most likely possibility. It is exceedingly unlikely on the gamete-dependence claim that a universe, our universe, full of organisms would contain one that was you. So there are a Vastly[17] large number of possibilities in which human beings exist but you do not. And even though you do exist now, you also believe that before you were born there was and after you die there will be an earth full of human beings and not one of them was or will be you. This unlikelihood of coming into existence and fact of non-existence before life and after death is the terror of non-existence so many of us feel regularly. And it is very real. So if there are Vast expanses of possibilities in which you don’t exist even though there are a large number of other human beings, and Vast expanses of time in which you don’t exist even though there are a large number of other human beings, why should any possibility and any period of time contain you at all?

From the start of our universe, your eventual existence was a possibility. This must be true, because you do exist now. (I’ll say more about that assertion in Part II, if I haven’t said enough already.) So why was it a possibility? Why, in fact, shouldn’t the universe have gone exactly as it did, and yet the time of your existence have passed by without you in it? In this scenario, were are imagining a sperm and ovum in our universe produced exactly as they were in the case in which you were brought into existence, in other words at the same time and place and from your parents, and joined exactly as they did, and yet the resulting person was not you.[18] This idea is actually just a new type of perfect doppelgänger. It’s a perfect doppelgänger without the rigmarole of the PD thought experiment. You already conceive of all the other people actual and possible not being you, so you can easily conceive of this person not being you either. So why was the resulting person in fact you, rather than not you? Especially considering how many other exactly identical human beings there could be who certainly, on the gamete-dependence claim, would not be you. Why did the coming into being of this particular one bring you into being?

When we ask such questions, it seems clear that you coming into existence is an additional fact to the coming into existence of a brain and body of a certain specification. (And this is one way of pointing out the problem of taking your existence to merely be an indexical fact on belief in the gamete-dependence claim, although the point can be understood independently of the indexical explanation.)

And there is another meta question on top of this one. Given the fact that this universe did bring you into existence, why this one and not another? Why was your coming into existence a possibility at the start of this universe, but not another? Of all the ways modern physics tells us there could be other universes—distant from ours in space, coming “before” or “after” ours in time (though in some sense not really in time, because our time began with our universe), in other dimensions, in and infinite number of big bangs “simultaneous” to ours, or whatever—we can imagine one physically identical to ours in every way, with identical physical laws and an identical amount of matter/energy and spacetime and all the rest, and having proceeded along the identical course, right down to every last physical detail of the physical facts that brought you into existence, and yet you are not there, you are here. In other words, you were not even a possibility in that universe no matter what happened there, just one here. This is actually what we were imagining in the previous paragraph, just in different terms. But we need not even imagine other universes identical to this one. No matter what the specifications of these other universes, for each one either your coming into existence is a possibility in it, or it is not. What determines which universe your coming into existence was a possibility in?

And this, of course, leads us to the final meta question: just append “if any” to the last question. Why should you coming into existence have been a possibility in any possible universe whatsoever? Why not not a possibility in any universe? If it was not a possibility in some universes, no matter how they went, then it could have been not a possibility in any universe at all. What determined that you were a possibility in any universe at all?

And that ends the questions. I know series of questions like this can be exhausting, but I think these are important questions. And I do have an idea that will answer them all in one fell swoop. So in the grand scheme of this essay, they are not merely rhetorical.

But first let me turn to the currently accepted answer, that existence is an indexical fact. This will still not be a full defense against this view, but it’s the most I can give you until I establish some other details and concepts in Parts II and III.

2. Everything Is What It Is And Not Another Thing (The Butlerian/Indexical View)


Imagine lottery tickets, each with a different number on it, in a pile as big as you like—as big as the universe if you wish, if not bigger; infinitely large if you think such an idea coherent. There is nothing the slightest bit problematic about my plunging my hand into the pile and picking out a ticket. Nothing could be easier. Whatever ticket I pick out will have a number on it that is the only instance of that number in the whole pile. If at this point I clap my hand to my head and cry: “My God, this is completely and utterly incredible! The odds against my picking this number were infinity to one against, and I’ve picked it. It’s impossible!”—I might feel goggle-eyed with wonder, but in fact this sense of wonder is totally misplaced, because whatever ticket I picked I could say exactly the same thing. And there is not the slightest difficulty about picking a ticket. So here is something that feels amazing but is not in the slightest bit odd. It is, as it were, a conceptual illusion. Now the important point is that this consideration applies to all questions about anything existing out of a wide range of possibility, however great—the sense of extraordinariness that this particular person should exist, or even that this particular universe should exist. Even if there were an infinite number of different possible universes there would not be on that ground the slightest room for surprise that this particular one exists. The only valid ground for surprise is that anything exists at all—e.g. that the lottery tickets are there in the first place (because once they are there, there is nothing left to explain).

–Bryan Magee, Confessions of a Philosopher


There are those who will say that all of the “why?” questions I’ve been asking throughout this essay are the wrong questions to be asking. They understand the questions, but believe they are bad questions. There is no “why” you are who you are rather than someone else or noone else, or why you are in this or any universe rather than not. It just is. Evolution produced a human body, and every conscious human body has to be someone. (The philosophical zombie is impossible.) It just happens that one of them is you. If one wasn’t, then all the other people could just as easily ask the same question and think they were asking something profound. But they wouldn’t be either. Pointing at your human body and saying “you exist because this exists” or at your gamete antecedents and saying “you exist because these existed” is just a correct statement of a brute fact, and there is no further “why” question to be asked about it. It is an illusion to think that there is.

This is a description of what we could call the indexical[19] view, and you may do so if you wish, but I’ll also call it the Butlerian view, after Bishop Butler’s famous dictum that “everything just is what it is and not another thing”[20]. I think of it as the stoical and sober-minded attitude. People see a problem only because they want to see a problem. Parfit puts it like this, in his characteristically excellent essay on why there is something rather than nothing:

We cannot sensibly ask why 9 is 9. Nor should we ask why our world is the one it is: why it is this world. That would be like asking, “Why are we who we are?”, or “Why is it now the time that it is?” Those are not good questions.[21]

            This is a compelling view. I understand what Parfit is saying, and find it very tempting. I agree that, for example, “why is now the time that it is” is a bad question, though superficially it might seem to be worth examining. If time exists at all (and in some sense it must, even if it only exists as an illusion or is otherwise created by our minds), then it always has to be some time and not any other, and so there is no need for further examination about why it is a particular time right now, and it is not an amazing coincidence or amazing luck that of all the times it could be, it is now. It just is because it had to be some time.

But I disagree that “why am I me?” is a question like this, that it is a bad question, if we assume Parfit’s own commonly held view about coming into existence, the gamete-dependence claim. If we believe the gamete-dependence claim, then “why am I me?” is a good question. (If you are not concerned with the question of indexicals, this is also a section that could be skipped or skimmed. The next section, section 3, really begins the heart of the argument, and should be understandable to any reader.)

What the gamete-dependence claim says is that, the conditions for your existence, conscious life, can exist, but you don’t necessarily exist. This means that, in addition to conscious life existing, there are additional specifications to you existing. But the problem is, once we look at these specifications—time of origin, place of origin, etc.—we find that our question still has not been answered. (The point I will explore in depth in the next section.)

This is different territory than numbers or time. The only condition necessary for the number 9 to exist is that numbers exist. The only conditions necessary for the present to exist is that time exists and the universe has lasted long enough. But on the gamete-dependence claim, your coming into existence isn’t obviously established even after the condition of the existence of conscious life is met. So on the gamete-dependence claim it is a good question what it was about this particular conscious life form and no other that it should bring you into existence. There was no possibility that numbers would exist but 9 would not be one of them, or that time would exist and the present would not be one of the times, either actual or just possible if the universe had happened to end before the present time came to be.

There is also nothing in numbers or time like the condition for you to exist that a body of a certain specification should exist. And so it is a further good question why was it that it should be possible for you to come into existence at all, rather than not. In all the numbers, there is no logical possibility that all the conditions for 9 to exist will be met, but the actual number 9 will be passed over, never exist. There is no alternate universe in which numbers exist but the number 9 is not a possibility. A similar thing can be said for time. Of all the times, there was no chance that all the conditions for the present to be reached might have been met, but the actual present never exists. There is no chance that the number 9 or the present might have been passed over without ever existing. But on the gamete-dependence claim, this is possible, both in alternate possibilities to the way things actually are, and in a meta-possibility that it might not even have been possible for you to exist at all.

I suspect this explanation will not be wholly satisfactory. I have another one to offer:

If we believe the gamete-dependence claim, there is a remaining unacknowledged but unanswerable arbitrariness hidden in the Butlerian view that makes it unsatisfactory, tempting though it may be in its simplicity and disposal of so many seeming problems. (And, as I said, I agree that it is very tempting, even on belief in the gamete-dependence claim.)

Sadly, I won’t be explaining this arbitrariness in detail until Part III, after we’ve gotten some other conceptual points under our belts to be wielded in the argument. But I can give you a quick and messy version now, to give you an idea.

Your existence, as I said, is not of the same kind of thing as now, or the number 9. Those things are one thing, and one thing only. They are one-dimensional. Anything even slightly outside of them is not that thing. No matter how many millionths or billionths or 10-10000000000000(to the power of a googol) above or below the number 9 you go, you no longer have the number nine, you have a different number. Same for a moment in time. But your existence is not like that. You are not one thing, one object, only. You have been many things: a ten-year old child, yourself now, and everything in between and much before. Each one of those things was a different object. And you could have been many different things, on belief in the gamete-dependence claim. You could have been a human being with a very different biography and living anywhere else on earth, or in outer space, if you had just gone there or been brought there sometimes after you were born or conceived (or your gametes were created). Each of those would have been a different object as well. And so there are many objects you could have been, and many others you could not have been, if you believe the gamete-dependence claim. In other words, something disappears when we move from the set of all of the objects in conceptual space that are/were/would have been you, to the set of all those that are not/would not have been you. On the gamete-dependence claim, it is not simply a shift of indexical view from one point in this conceptual space to another, with each shift being exactly equal to the others, but it is the maintenance of a particular sameness between some shifts and not others. This is unlike the usual conception of indexicals as an answer to a problem. It adds a factor in that the idea of an indexical doesn’t answer.

To put it yet another way, there must be a sort of fence in conceptual space between those two types of objects, the ones you were or will be or could have been, and the ones you were not and will not be and could not have been. Where to place the fence? It’s not as clear as it might seem. Even if it seems relatively straightforward for you now, after you already exist—just trace this body through space and time—when we get to the time of origin, where and why to place the fence becomes much more difficult. As we will see in Part III, we are forced to choose an arbitrary location.

I suspect that this too will not be a wholly satisfactory answer to the indexical/Butlerian objection. As I said, it is the quick and messy version. The full explanations come in Parts III and IV. If nothing else then, I just want to acknowledge that this objection exists and has force.

And I will repeat and emphasize this: I do not actually reject the indexical/Butlerian view. I merely believe that it is inconsistent with the gamete-dependence claim. But, if we radically alter our view of existence, to what I argue for in Parts III and IV, then we can get the question of “why am I me?” to be of the same type as “why is now the time that it is?” or “why is this the world the world it is?” (or “why did I pick this lottery ticket out of all the lottery tickets in this pile?”). We can make the indexical/Butlerian view the correct view for our own personal existence as well, by changing what we believe about our own personal existence.

3. Gamete Identity: Explanations and Necessary Conditions for Your Existence

 a. The Current Beliefs

It is clear that a great many people take certain physical facts to be explanations of their own existence. Ask anyone—or at least any materialist—why they exist, and they will likely give you one or more of the following answers: because my parents met and had sex with each other, because that one sperm won the race to that one ovum, or because of my DNA.[22]

Parfit specifically appealed to parentage and gametes in his time-dependence claim, which I renamed the gamete-dependence claim. But there are many other writers just as esteemed as Parfit, and many less so, who make the same claims. As promised, I’ll provide some examples.

To start with, in The View From Nowhere, Thomas Nagel says

Subjectively, we begin by taking our existence for granted: it is a given of the most basic kind. When in childhood each of us first learns of the contingency of his existence, even the simple fact that it depends on his parents, the result is a lessening of his unreflectively secure footing in the world. We are here by luck, not by right or by necessity.

Rudimentary biology reveals how extreme the situation is. My existence depends on the birth of a particular organism that could have developed only from a particular sperm and egg, which in turn could have been produced only by the particular organisms that produced them, and so forth. In view of the typical sperm count, there was very little chance of my being born given the situation that obtained an hour before I was conceived, let alone a million years before, unless everything that happens in the world is determined with absolute rigidity—which appears not to be the case. The natural delusion of my own inevitability collides with the objective fact that who exists and has existed is radically contingent, my own existence in particular being one of the most inessential things in the world. Almost every possible person has not been born and never will be, and it is sheer accident that I am one of the few who actually made it.

Nagel gives parentage and a particular set of gametes as the criteria. Note also the continuation of his attempt to grasp at the inchoate perplexity of existence from the previous passage I quoted in my biography section, which appears in an earlier chapter of the same book.

Richard Dawkins provides an even longer and more evocative statement of the belief, and it’s my favorite one. These are the paragraphs that begin his book Unweaving the Rainbow:

We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who in fact will never see the light of day outnumber the sand grains of Arabia. Certainly those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here.

Moralists and theologians place great weight upon the moment of conception, seeing it as the instant at which the soul comes into existence. If, like me, you are unmoved by such talk, you still must regard a particular instant, nine months before your birth, as the most decisive event in your personal fortunes. It is the moment when your consciousness suddenly becomes trillions of times more foreseeable than it was a split second before. To be sure, the embryonic you that came into existence still had many hurdles to leap. Most conceptuses end in early abortion before their mothers even knew they were there, and we are lucky not to have done so. Also, there is more to personal identity than genes, as identical twins (who separate after the moment of fertilization) show us. Nevertheless, the instant at which a particular spermatozoon penetrated a particular egg was, in your private hindsight, a moment of dizzying singularity. It was then that the odds against your becoming a person dropped from astronomical to single figures.

The lottery starts before we are conceived. Your parents had to meet, and the conception of each was as improbable as your own. And so on back, through your four grandparents and eight great grandparents, back to where it doesn’t bear thinking about.

Dawkins then quotes from the autobiography of Desmond Morris (b. 1928), where Morris points out that he “might not be sitting here writing these words” had one of Napoleon’s cannonballs (c. 1810) not shot off the arm of his great-great-grandfather James Morris. Dawkins finishes on this note:

There’s no “might” about it. Of course he owes his very existence to Napoleon. So do I and so do you. Napoleon didn’t have to shoot off James Morris’s arm in order to seal young Desmond’s fate, and yours and mine, too. Not just Napoleon but the humblest medieval peasant had only to sneeze in order to affect something which changed something else which, after a long chain reaction, led to the consequence that one of your would-be ancestors failed to be your ancestor and became somebody else’s instead. I’m not talking about ‘chaos theory’, or the equally trendy ‘complexity theory’, but just about the ordinary statistics of causation. The thread of historical events by which our existence hangs is wincingly tenuous.

Dawkins gives both of the elements that I mentioned that Parfit and Nagel also give, gametes and parentage, but also gives the third one I mentioned, DNA. Perhaps Parfit and Nagel would just consider DNA to be subsumed by the “gametes” criteria, or perhaps they deliberately left it out due to the complication of identical twins I address below, but many people besides Dawkins do explicitly give it as a separate criteria, as we shall see, particularly when talking about the odds of existence, where the odds of hitting upon a certain genetic sequence in DNA and the odds of two gametes joining are a completely separate calculation, and each considered astounding in their own right.

The reason I quoted both these passages in full is to get a sense of the emotional resonance associated with this belief. The idea that these criteria had to obtain in order for you to exist really matters to people, and in Nagel’s and Dawkins’ eloquent writing, we can really feel how it matters to them, and they make it matter to us. This makes the belief extra-interesting to explore. And important for another reason: although I think no one was previously really making the distinction between content and existence the way I’ve made it here, and so I cannot apply my distinction directly to those who have written in the past, it is clear to me from, among other things, the astonishment these writers express about it when they say their existence depended on these unlikely physical factors, they are talking about the same personal existence I’m talking about, and not merely the existence of a particular human body, as I was careful to distinguish with the DS acid test. (If they were, I would think they’d simply take the attitude expressed by the Bryan Magee quote in the previous section about the lottery.) And further it seems clear that they are imagining the total and irrevocable absence of their personal existence in these cases, not the absence of any particular content.

I can imagine a variation on my Socratic dialogue above that would illustrate this latter point:

A: When we talk about our personal existence, we are talking only about content, a personal or self narrative. I am, and only am, my personal narrative.

B: So what would be the case if you had been kidnapped at birth (more precisely: the baby your mother gave birth to that you right now call the earlier you had been kidnapped at birth) and taken to a distant country, and therefore the adult it became right now had a completely different personal narrative?

A: I would not exist.

B: And what would be the case if your parents had never met?

A: I would not exist.

B: So then, would you not exist in the same way you wouldn’t exist if that baby had been kidnapped at birth, or in a different way?

Once again, I feel everyone surely must answer “in a different way”. So I believe writers who express this belief in these physical criteria for their own existence must mean personal existence in the way I’ve defined it, as the phenomenon of existence isolated from any specific content.

Before I give some other examples that are clear expressions of this same belief,  for the philosophers here I’ll point out that what many take to be the foundational expression of what I’m calling the gamete-dependence claim for philosophy is by Saul Kripke in Naming and Necessity from 1971[23] (although I feel it must have been a folk belief ever since gametes were discovered). Kripke’s may also be the most esteemed and influential expression of it, but Parfit is in competition for that. Kripke’s claim is an answer to the question of what, if anything, is the essential property of a particular human being, i.e., what is the property that that human being has in all possible worlds. It cannot be something like “was president of the United States” or “studied philosophy”, as any person might have or might not have done those things, i.e., might have had those properties, and still existed. Kripke’s answer for this property was their origin in a particular set of gametes.

Kripke may not be asking the same questions I’m asking though; I feel I can make less claim that he must be talking about what I’m calling personal existence than I can for Parfit, Nagel and Dawkins. And I think this is true of everyone working on modality or necessity or transworld identity or whatever you wish to call it. Everyone in this field seems to be concerned simply with the transworld identity of objects, and they thereby attempt to treat people just as human-body objects, i.e., in the same manner as any other object. The first-person perspective of what I’m calling personal existence is rarely if ever mentioned, and I would wager that most philosophers in this field think it is unnecessary if you are a materialist or self-evidently illegitimate.[24] Tellingly, when writers in this field do their thought experiments and ask their questions about people, they rarely do them on “you” or “I”, as Parfit and other personal identity theorists do, but rather on famous human beings such as “the queen of England” or “Nixon”. For example, here’s the relevant passage by Kripke, which is on the question of whether Queen Elizabeth could have been the daughter of Harry and Bess Truman:

How could a person originating from different parents, from a totally different sperm and egg, be this very woman? One can imagine, given the woman, that various things in her life could have changed: that she should have become a pauper, that her royal blood should have been unknown, and so on…But what is harder to imagine is her being born of different parents. It seems to me that anything coming from a different origin would not be this object.

Kripke then goes on to discuss whether the table in front of him could have been made from another block of wood or of ice. That there might be an even prima facie difference between these examples is not mentioned.

Since I can’t clearly (or at least consistently) catch Kripke in the act of internal imagining, I’m reticent to include him and others who work on transworld identity in my lineup of people who have expressed the beliefs I’m examining (I’m thinking for example of Forbes and P. Mackie). I felt I needed to include this commentary here first simply because of how famous this work and passage is. And it is good to take note of it anyway, because in this field of transworld identity where it seems to me the distinction is rarely made between the object view and the internal view, I do suspect that a great many people are surreptitiously or at least subconsciously thinking of the internal “personal existence” view anyway, even if they ignore or abjure it. I’ll have more to say on this as I go along, particularly in my comparison of my views with those of David K. Lewis in my conclusion.

But Kripke and transworld identity theorists aside there are still many other people who, similarly to Nagel and Dawkins, certainly have expressed the sentiments I have in mind: citing one or more of the criteria mentioned as essential to their own existence, and also expressing in some way how astounding or disturbing that is. (I’ll note the criteria appealed to in parentheses after each quote.) Physicist Frank Close in his book The Void is trying to grasp the incomprehensibility of himself not existing, and yet the amazing fact that he does, when he says “…there is an infinite number of possible forms of DNA all but a few billions of which will never burst into consciousness.” (DNA.) Psychologist David P. Barash in his essay “What The Whale Wondered” is pointing out the ultimate meaninglessness of human existence when he says, “…nobody arrived here [on earth, i.e., was born] except because of a chance encounter between a particular sperm and a particular egg. Had it been a different sperm, or a different egg, the result would have been a different individual.” (Gametes.) And philosopher Jim Holt in his book Why Does the World Exist? is grappling with the idea of personal existence itself, much as I am, when he says,

If your parents had never met, of course you would not exist. But much more than the mere meeting of your parents, or even their sexual congress at a particular moment in history, had to go improbably right in order for you to see the world. Perhaps the entity that really deserves your gratitude is not your mother or your father, but rather the plucky little sperm that, carrying half of your genetic identity as its cargo, gamely made its way through the amniotic sea, past millions of its ejaculate-rivals, to unite with the egg.

Holt immediately follows this up with the right question, which we can all recognize clearly by now: “The coming into being of my genetic identity was indeed a long shot. But was even that enough to ensure the coming into existence of me? Could this genetic identity not just as easily produced not me, but, as it were, my identical twin?” (Parentage, gametes, and DNA.)

There are examples of the expression of this belief outside of the academic intelligentsia as well. The top Google hit for the question I started this essay out with, “What are the odds that you would exist?”, leads you to a blog post and infographic by self-help guru Ali Binazir in which he attempts to go through actual calculations to arrive at the odds of your parents and then your gametes meeting. (Parentage and Gametes; in a moment I’ll quote a commenter on Binazir’s post who denies that these two criteria matter, and claims only DNA.) Binazir’s point is: the odds were astoundingly long, so “go forth and feel and act like the miracle that you are.” And here’s the magician (and popular intelligentsian) Penn Jillette, in an interview with Marc Maron on his podcast WTF:

I don’t need everlasting life. Who could need more than [what we have]? How can you breath a breath of air, how can you hear a wonderful piece of music, see a beautiful piece of art, feel the love of your friends and family, and go, “yeah, but this is just a veil of tears…beyond this is the real happiness”? I can understand if you’re in Auschwitz. But living in the United States of America? And having children who love you? And having friends that you can hang out with? Going to see great movies, and then you go, “yeah, but the world beyond is so much better”. How greedy are you? You’ve been given everything! You have won the most amazing lottery that has ever been given. The chances of you being alive are zero. Just point zero zero zero zero zero zero zero— [makes noise implying a many more zeros] —one that you happen to be here.” (Episode 231)

Jillette doesn’t specifically cite the factors he has in mind for his miniscule number, but I feel pretty safe it is some or all of the three I mentioned. Again, I include all these full quotes to give the flavor of the emotional valence of this belief for people.

So we can see the belief in these criteria popping up in more or less detailed analyses and tossed off asides in all sorts of places and across all sorts of discourses. It seems to be an extremely common belief, and perhaps is considered to be the required belief for materialists.

Perhaps I’m being unfair to all these people though. I started out this section with the claim that many people take certain physical facts—DNA, gametes, parentage—to be explanations of their own existence. I feel this is undoubtedly true. But perhaps none of the writers I’ve quoted or cited would explicitly make that claim. Perhaps, being more careful (and many of them being professional philosophers), they would say they are merely claiming that these physical facts were the necessary conditions for their coming into existence. In other words, that these facts had to obtain, had to come to pass, for them to have come into existence. Without these things happening, they would not have existed. It is possible to believe this without taking the extra step to claiming they function as explanations. We can just believe that they are necessary conditions without knowing why that is so, without discovering the reason for it to be true, or any particular connection between their existence and these physical facts.

If this is the case, I will happily absolve them of the accusation. I think that generally though people are not particularly careful about distinguishing between explanations and necessary conditions when talking about why they exist; certainly among the general public, and possibly among some of the philosophers among these writers as well. And anyway, I don’t right now have a good definition of what an explanation is[25], or how it would relate to a necessary condition. I’d like to get one one day. But for now I’m going to just take on these two beliefs in parallel. My main topic will be the belief that these physical factors are the explanations for why you exist, are the established and conventionally accepted answers to the question “why do you exist?”. As a sub-topic, when it comes up, I’ll provide some discussion on how these factors fare as necessary conditions, and also as sufficient conditions.

b. The Three Conditions: The Relationship Between DNA, Gametes, and Parentage

So we have the three factors that people speak about casually or write about in carefully argued philosophical works: DNA, gametes, and parentage. We can note immediately that these factors are not all of an equivalent type though. “Gametes” sticks out as a factor, because parentage and DNA are actually sub-factors to gametes, necessary conditions for a particular set of gametes being those gametes. Put another way, parentage and DNA are essential properties for gametes. And when we see it this way, we see immediately that there is much missing from this standard simple presentation of the belief: surely none of these people take parentage and DNA to be the only essential properties for a set of gametes. It is clear that both of these properties could be the same for any number of gametes, and yet only could be the pair to produce you. In other words, either of your parents could have produced any number of other gametes with the same DNA, and yet they would not all produce you. Only one set of gametes produced by your parents with that particular DNA would have produced you.

Once again, you may be tempted to deny this statement, to claim that you would have been the person that resulted from any set of gametes with that exact DNA combination from your parents, but once again I ask you to think about what any B person would have to say about that had both your A gametes and a set of B gametes produced a person. The B gametes could have been gametes from your parents as well, and this B person could have come into existence along with you, the A person. And so the B person would naturally assume that he or she would be the one to come into existence if the A gametes had not been created or had not been joined, not you. So the belief that you would have come into existence from any set of gametes produced by your parents with your particular DNA, however plausible it may sound on its surface, is not consistent with other things you believe when you look at it closely.

So if only one set of gametes among a very large number of possible gametes of identical DNA produced by your parents would have brought you into existence (that one set being by definition the A gametes), then there must be some factors distinguishing those gametes (the A gametes) from all the other gametes identical to those gametes that your parents could have produced. In other words, there must be a number of tacit essential properties (as opposed to the explicitly stated properties of DNA and parentage) hidden under the guise of just making the claim that “gametes” are a necessary condition for your existence, as everyone I’ve mentioned does. Here’s five possibilities for what those other essential properties might be taken to be:

  • The exact structure or plan or shape of the gamete, inside and out (this includes DNA, but also involves everything else about the structure as well), had to be exactly what it was in order for it to be a gamete that would bring you into existence
  • The particular atoms or matter that went into the construction of the gamete had to be exactly the atoms they were in order for it to be a gamete that would bring you into existence
  • The time or timing of the formation of the gamete had to be exactly when it was in order for it to be a gamete that would bring you into existence
  • The location of the formation of the gamete (either in absolute space, or relative to the space in the gamete-producing organ of a parent’s body) had to be exactly where it was in order for it to be a gamete that would bring you into existence
  • The process of formation of the gamete had to be exactly as it was in order for it to be a gamete that would bring you into existence

These are only possibly the tacit essential properties that people are thinking of. Most people don’t think of them at all, and if they do, may not consider them all, and may not consider any of them essential when they do consider them. But, since there must be something besides just DNA and parentage that would be essential to a set of gametes being the ones that produced you, it seems reasonable to believe that the gamete-dependence claim entails that at least one of these must also be essential, and maybe that more than one must be essential, and maybe that all of them must be essential.[26]

All of this makes quite plain that people often make versions of the gamete-dependence claim without particularly analyzing the relationship to each other of the factors they give. Gametes are placed alongside DNA or parentage as though they are separate properties of the same type. And people sometimes mention one or more of these factors without mentioning the others.[27] As I said, Parfit and Nagel only mention gametes and parentage, while Dawkins mentions these two plus DNA. Dawkins also mentions the complicating factor in taking DNA to be a factor, identical twins, as did Jim Holt. And Parfit mentions monovular twins in a footnote to his claims about DS, also recognizing it as a complicating factor. (In reality, DNA is no more problematic than any of the other factors, it just appears to be, but I will get to that in a moment.)

An even better example of people only considering some of these factors and not others comes from Ali Binazir’s blog post about the odds of coming into existence. Binazir as I said also appeals only to gametes and parentage, but then a commenter chimes in with “Fun post – my only quibble is about the probability of the right sperm meeting the right egg. You estimate 1 in 400 quadrillion. However, I don’t really care about specific sperm and egg – I only care about specific genetic material. In other words there are 23 chromosomes in the human genome. I need to get the exact set of 23 pairs that creates me.” (DNA.) This commenter is saying that he or she thinks that neither gametes nor parentage matter, just that some set of gametes from somewhere be brought into existence with his or her DNA sequence. I think the commenter could easily be made to see the error of this belief by pointing out that many gametes with the same DNA could be brought into existence and they could not all have been him or her, but the point is just that someone has had this thought, and likely a lot of people have. It will be good to keep this in mind as we look at what all of these beliefs amount to.

c. Inhering Existences in Material Objects

Let me be clear that on the face of it there is nothing absurd about the belief in the gamete-dependence claim. It makes excellent sense. We trace our existence through the world by tracing our physical body through space and time. Trace back from the present and you come to the body of the child that was you, the infant that was you, the fetus that was you, and the zygote that was you. Before that we get the gametes, and on this reasoning it is perfectly sensible to call them the gametes that were you; they were after all, the physical structures out of which the zygote was made. A different zygote would have to have been made from different gametes. At most, you may wish to believe DS, and just say the ovum that was you, whatever sperm fertilized it. In fact, this physical body tracing method makes it clear why DS is an appealing belief. The ovum is the matter of the zygote when the zygote first comes into being. It is the object we are tracing. The sperm essentially only adds information. The additional matter a sperm adds to the cell when it penetrates it is utterly negligible: the sperm is .00167% the mass of the ovum; the ovum is 60,000 times the mass of the sperm. This is about the mass ratio between an African elephant and an apple.

But whether you choose to believe DS or that both gametes were required to bring you into existence, tracing the physical object back through time to gametes to trace the existence of a person is perfectly sensible.

But note one thing this belief entails. In order for a person to exist, there must be a brain. There is no personal existence without consciousness, without content, and there must be a brain for there to be consciousness or content. Yet, zygotes and gametes have no brain whatsoever, not even the slightest trace or hint of a brain. A brain is built from scratch, from nothing, from the first molecule upward, some time after the zygote forms (starting at 2-3 weeks, according to the internet).

So go back to PD and look in your mind’s eye at those two sets of gametes in those dishes on that scientist’s bench. Look at the A gametes. Then look at the B gametes. There is something odd here: there is no brain, but nonetheless, in the A gametes, there you are, carried around wherever those gametes might go (even to a spaceship!). In the B gametes, there you are not.

There is a word that comes to mind here. It seems like we believe that you are inhering in those A gametes. Or maybe we should say that the potential for you is inhering in those gametes. Looking at absolutely identical sets of gametes makes this quite clear. You are somehow “in” one of them, but not the other, or any other.

Ratchet this up to a universe-filling number of identical gametes and play the same game. Of all those gametes, if any of them produce you at all, just one pair does. In that universe-sized mass of gametes, there are just two that have you inhering them, even though all the sperm are identical to each other and all the ova are identical to each other. All of the others, there you are not.[28]

            I think many people will find this term “inhere” illegitimate, especially those who believe that indexicals are the answer to the mysteries I’ve been describing, since I have not yet fully explained why the indexical answer is incompatible with the gamete-dependence claim. But I think “inhering” is merely the correct term to describe what most people actually believe. More importantly, I think it is the correct term to describe the beliefs of anyone who believes in the gamete-dependence claim, regardless of what beliefs they proclaim about indexicals. So even though I have not yet fully justified my use of it, I am going to avail myself of it freely. Because if you believe that a particular zygote or a pair of gametes was you, or was the only possible object in the entire universe that could have brought you into existence, then you believe a lot of other things as well, and we need a term like “inhering” to carry with us to help us get it straight. You can take me to be addressing just people who have never considered the indexical answer if you like, because in large part that is what I’m doing (they comprise the vast majority of all people, so it is well worth it), but do mind whether I’m not also describing your actual beliefs as well.

d. Gamete Identity: The Three Conditions, Separately Considered

            So let’s finally consider now in detail the three conditions people generally give when asked why they exist, or what was necessary for them to come into existence: DNA, gametes, and parents. Even though DNA and parentage are actually properties of gametes, I’ll consider them each as factors on their own, since this is the way people usually talk about them. When I get to gametes, I’ll divide that discussion into the five possibilities for additional essential properties that I mentioned above.

We can call this an examination of gamete identity. It might better be called the personal identity of gametes, the identity of the person “in” the gametes, or who will become from the gametes, but gamete identity seems fine to me. I name it so, because it is interesting to me that Parfit and others have pored over personal identity in such exhaustive detail, yet they seem to just accept gametes as the answer to origins of a person, without analyzing them any further or examining whether this is as obviously true as it seems, or whether there might be any problems with this belief.

Some writers on transworld identity have looked at gamete identity, but as I said, they abjure the personal (first-person) perspective, and just treat human beings as objects equivalent to all other objects. So I do not want to claim I am the first to discuss it. My point is just that I find the omission by personal identity theorists to be curious.

i. DNA


I’ll start with DNA, because it is the property that is prima facie on the least philosophically solid ground. This is because the evidence against it as an explanation at least stares us in the face on a regular basis: the millions of pairs of identical twins (and triplets and on up the line) in our world already. If other people could have existed with the same DNA as you, then a person with your DNA could have existed without you existing. Therefore, DNA does not explain your existence, or even play a part in explaining your existence. This is not a far out thought experiment, or an extremely unlikely science fiction scenario. It is a mundane empirical fact.

Careful writers who mention DNA often immediately refer to this difficulty. Dawkins did in his quote above, pointing out that “there is more to personal identity than genes, as identical twins (who separate after the moment of fertilization) show us.” Jim Holt does as well when he mentions it: “The coming-into-being of my genetic identity was indeed a long shot. But was even that enough to ensure the coming-into-being of me? Could this genetic identity not just as easily produced not me, but my identical twin?” (255)

But it is still an extremely common belief that people have about themselves, that DNA explains their existence. Many people believe their existence essentially depends on their DNA blueprint, in some way, as did the commenter above on Ali Binazir’s blog post. Whenever anyone marvels at the long odds against their particular combination of DNA coming to be, they are appealing to this belief, including, I think, Dawkins, his qualification of it notwithstanding.

Probably, most people are thinking, though often not stating explicitly, that DNA is a necessary but not sufficient condition for coming into existence. This more precise statement could be true. We can say, in order for you to come into existence, the exact combination of DNA that produced you had to come to be (necessary condition). But put the statement in the other direction, and it’s simply not true: you would necessarily be the person to come into existence with that combination of DNA (sufficient condition).

But is it necessarily a necessary condition? In other words, can we see why it must be a necessary condition? This is where an explanation would come in and settle the case for us. An explanation for example of how DNA relates to your existence, of some connection between the two. But there is none, and so it remains unsettled. It is therefore worth asking why we do take it to be a necessary condition. (I’ll come back to this question at the end of this section.)

Parentage actually has the same status as DNA in regard to you coming into existence: it is even more obvious as a necessary (if it is necessary) but not sufficient condition, since nothing is more obvious than that any parents could produce more than one child and that most parents have in reality done so, and parentage is also lacking the explanatory power in the same way that DNA is. That everyone mentions parentage as a necessary condition but some people get scared away from mentioning DNA by the existence of identical twins is more evidence that people have not analyzing these factors carefully before professing their belief in them.

Further, monovular twins, which is the only way identical twins have actually been produced in our world (as far as we know), actually have all of the possible essential factors in common, including the additional five hidden in the condition “gametes”, such as time and location of creation. So none of the essential properties usually given are sufficient conditions, even in aggregate. The most we can say is they may be necessary conditions, without explanation. I can say that I would not have come into existence had those conditions not obtained, but I cannot say that I would have come into existence as long as those conditions obtained.

There is one way in which DNA is truly a unique property in this lineup though. All of the other properties refer directly to a physical object, such as a particular gamete, a particular human being to be a parent, or particular atoms, or some other aspect of the physical world, such as time or location. DNA in contrast is just pure information. It is physically embodied in the DNA molecule, to be sure, but the aspect of it that matters to us is the information it encodes.

This gives us an interesting question to consider, building off of what I mentioned in the previous section: if personal existence requires a brain, and if there is no brain in a pair of gametes, then perhaps the object we should have been tracing back to all along is the brain, not the gametes, and so the origin criteria we should be looking at is the origin criteria of that brain, not those gametes. The gametes are just environment and instructions, but on this view it is hard to see how their history before the start of brain production could matter to the “identity” of the brain. In other words, could that brain (whatever we may take that to mean) have been built by other means than the zygote that was produced by those gametes? Perhaps a zygote produced by identical gametes in the same place and time using the same matter? By a gamete- and zygote-free artificial process in the same place and time using the same matter?

            Think of it in these terms. The Empire State Building was built from plans. Let’s imagine a large blueprint. It was actually a volume of blueprints, of course, but for simplicity lets just imagine one sheet. The sheet is a physical object, but the information within does not depend on any particular physical object. If the blueprint is copied, the information is still the same. Even if it is memorized by the builder, and he or she caries around no physical copy at all, it is still the same information. In an alternate universe, as long as the building is built on that plan with those materials (and perhaps in that location, but perhaps not), we would have no trouble at all calling it the same Empire State Building. Unlike, say, if it had been built on a slightly different plan or with a few different bricks. Then we get into an area of indeterminate answers as to whether it is the same, and we just have to choose whether we want to call it the same or not. But if, in an alternate universe, the builder loses the original blueprint and builds from a different copy than he or she did in this universe, this troubles our claims of transworld identity not a whit.

So DNA should follow the same idea. A different physical embodiment of the same DNA, in a physically different sperm for example, could build the same person, if it was built at the same time and place and of the same materials, etc. This would be one reason to think the B gametes would have produced you, if they had been implanted in your mother before they started making a brain.

I will not pursue this further, because this is not my conclusion, and my actual conclusions render this point moot. But it does raise questions about our usual assumptions.

I will take up DNA as information again in Part III, where it becomes central to one of my arguments. For now the takeaway is that DNA may be a necessary condition, is definitely not a sufficient condition, and is not any sort of explanation, for why you exist.

ii. Other Candidate Essential Properties of Gametes

So let’s look at the second condition: that a particular sperm had to join with a particular ovum. Here I return to that controversial word “inhering”. Looked at just as objects, without considering their features, we somehow believe that there is some essence of “youness” inhering in those gametes, that would not be inhering in any other set of gametes, even identical ones.

            This is especially striking if we believe the A gametes would have still remained the A gametes (in other words, the gametes to produce you) had the atoms all been swapped out after their creation. Remember that any living thing can lose and gain atoms. It almost seems magical, this “spirit” of “youness” remaining inhered in that structure of matter at that point in time and space as the pieces of matter themselves come and go freely, like a ghostly light glowing from no source. Almost, in other words, like a soul.

            Consider this from the perspective of two questions we could ask that are more specific and empirical than just “Why do you exist?” We can instead ask “What had to obtain in order for you to exist?” and “What conditions would have led to you not existing?” To find a better answer to these questions than just “gametes”, we should look closely at what goes into the formation of a particular set of gametes that, at the end of their formation, have become the ones that will produce you. Let’s use just a sperm as the example, since it is produced near the time that it would take part in the creation of a person, and ignore the possibility raised by DS for now. Looking at the sperm as an assemblage of parts and characteristics, we end up with the five factors I mentioned above, which I will list here again:

  • Structure or plan
  • Matter
  • Time
  • Location
  • Process of formation

            If you believe, as I think you do, that your personal existence was inhering in the zygote and the gametes before it even though there was no brain in those structures, then I think you also believe that such a thing was inhering in these factors that went into ensuring that those gametes were those gametes, that that sperm was that sperm. So we can ask questions like, was the potential for your personal existence inhering in those atoms before it came together into that sperm? In other words, was it necessary for those atoms and no others to come together in order for a sperm to be created that would bring you into existence? (This amounts to the belief in “inhering”, even if you don’t like the term.) We might believe that this is so. But then we remember, which atoms make up a person don’t matter, and we can easily conclude that which atoms make up a sperm don’t matter either. If it matters what atoms go into the creation of the sperm, why does it suddenly not matter a few moments after the creation, when they presumably can be swapped out? And if it did matter which atoms were there at the origin of the sperm, we might wonder whether the food your father ate around the time his body made that sperm would have affected whether the sperm he created would be the one to bring you into existence, even if it was a sperm of the same structure. If so, were you inhering in that plate of spaghetti, but not the burger he might have had instead?

            If the atoms are not allowed to vary, we can also consider time or location. Presumably, a sperm identical to the one that created you could have been created out of the same matter and of the same structure, but instead of at the time the A sperm was created, at a slightly earlier or later time, or a slightly different location. Would that still be the A sperm, the sperm that produced you? If so, what then would we say if, in addition to that, an identical sperm were created out of different matter at the same time and location as the A sperm in this universe? Which of the two would have claim to being you, the one created of the same matter at a different time or location, or the one created at the same time and location of a different matter? Either we say “you” inhere in the matter, or the time and location. We have to believe that one of the two is somehow the deciding factor for your coming into existence. Yet it seems absurd to postulate any of them as such. What would be the reason for such a thing as matter, location, or time of creation to be the cause of your existence, to be the reason you came into existence, to be the factor inside a certain parameter of which you came into existence but outside of that parameter you would not have?

Or we might examine the way in which the sperm was created, and wonder if there was something in that process that caused it to be the sperm to bring you into existence, as opposed to being a sperm that brought about a state of your non-existence. A structurally identical sperm of the same matter could have come together through a different process at the same time. We could wonder whether activities by your father such as playing basketball or watching television (comedy or drama?) would have affected such as thing. Was there a potential for you inhering in a process of formation?

The point of all this is that it’s not enough to simply draw a fence around the gametes and say, those are the ones, and no others, because we can simply look closer at those gametes, and wonder where the fence for those gametes being those gametes is. Pointing at the gametes still leaves us with questions about gamete identity. We quickly see that the purported explanations are no explanations at all. Instead of “these gametes are the conditions of your coming into existence”, we just move the question back to, “this matter/process/time/location/structure are the conditions of your coming into existence”. And much moreso than gametes, it’s easy to see that none of these factors offer any sort of explanation at all. To adopt the terminology Parfit uses for minor conditional variations around personal identity, these factors just don’t seem important enough to be the difference between your existence and your non-existence.

It is easy to see though why so many people feel like DNA or gametes are a great “eureka” moment in searching for an explanation for their own existence. Gametes provide a tidy answer, and it is convenient that they are a real object. But as explanations, they are similar to a homunculus (the proverbial “tiny person in your head”). Simply stopping at the gamete-dependence claim as an explanation for existence is akin imagining that a homunculus would be an explanation for thinking, and both function as an assumption that we can hide even from ourselves on our most careful reflection. But neither answers the question they are put forth to answer. They both just push the explanation onto a smaller or earlier object and thereby give the illusion of answering the question.

iii. Parentage

Consider now the third condition, that our parents would have to meet and copulate. It is an easy claim to make that it is not enough for the gametes to merely have the same construction at the same time as the gametes that produced you, they must have had the correct source: your actual parents. One can imagine a situation in which your parents never existed, but gametes identical to the ones that created you came into being at the same time and location in space and from the same matter and the same process, but from genetically different people. Would the resulting person have brought you into existence anyway?

Perhaps this is too far-fetched. It seems imaginable, but maybe that’s just because I’m not concerning myself with the details. But whether it is actually possible or not, this sort of thought guides us to an essential question: what exactly did your parents actually contribute to those A gametes being the ones to produce you? This is especially stark if this factor is isolated, if we ask it without being able to appeal to any of the other factors I’ve already dispensed with, such as DNA, location, matter, etc.

But if we just accept that the identity of your parents must hold, then clearly the identity of the gametes that produced your parents must hold, and the identity of the gametes that produced their parents must hold, all the way back to…well, Dawkins says it doesn’t bear thinking about. But it clearly does, and not just because the odds we come up with for all of these things obtaining are so incomprehensibly long, but because examining it closely leads us to wonder why we think this condition matters at all, and forces us to own some pretty strange beliefs if we do decide it matters.

To start, we must ask all the same questions about the gametes that produced your great-great-great-great-great grandmother as about the gametes that produced you. Except there is an additional factor: not only must we think that the existence of your great-great-great-great-great grandmother was inhering in the gametes that produced her, but also your existence as well. If your great-great-great-great-great grandmother is part of the criteria for you coming into existence, then the potential for you must have been inhering in the gametes that produced her. And the existence of every parent and grandparent in between. Look at the formation of one of those gametes in your mind’s eye, and just imagine the potential for you and all of your ancestors since to come into existence somehow inhering in there in those gametes, and then being built into just one ovum and no other of your great-great-great-great-great grandmother as she grew in her mother’s womb, and being carried with her as she is born and grows up, and then sent forward into your next ancestor when she conceives with that one ovum.

And we must keep going further back. A famous person from the past could be your ancestor. Perhaps Augustus Caesar. Just imagine, Augustus Caesar himself going about his young life and the early part of his reign in Rome, doing his Emperor things, and there you are, the potentiality for little old you (and a great many other people, but not an exponentially larger number of other people besides you and this first group of other people) being carried around with him with his every famous and important movement, wherever he goes, just waiting for him to produce the right sperm at exactly the right moment and copulate at exactly the right moment to ensure that you will come into existence a few thousand years into the future.

And consider too that at the time of Augustus Caesar you didn’t have just one ancestor, and most likely had more than two or four; you probably had dozens or hundreds or thousands or millions.[29] They were all carrying around the potential for you, waiting to create and release just the right gamete at the right time, and if any of them had “failed” in this, or had failed to exist at all, then you wouldn’t exist right now.

And of course, it must go back to before the evolution of humans even. Look at another of your ancestors now, an ape-like creature, sitting in a tree some millions of years ago. According to standard belief, that ape had to copulate at the exact time as she did with your male ape ancestor, and that exact sperm had to fertilize that exact ovum. And we can ask all the same questions about those gametes as we did about the ones that produced you. There you are, you personally, inhering in that ape sperm and ape ovum, and in every set of gametes before and since in your line of decent.

Eventually, when we keep going back, we get to asexual reproducers. If just one of the hundreds of trillions of organisms in the oceans of earth those billions of years ago had fissioned in just a slightly different manner, would you have never existed? This seems to be the belief espoused by a great many people. But what would that even mean, to “fission in a particular manner, but not another”? If this single-celled organism splits here, your potential to come into existence will be carried forward, but if it splits there, it will not. What is a sufficient distance to make that difference? A single atom?

We can take it back even further, to the first bare replicator molecules. Or even to the matter that existed before replicators came into being. Look at that primordial soup, with all of those atoms and molecules floating around. One set of them comes together to become the first replicator. If it had come together just slightly differently, with one molecule in the chain different, or with even one atom different, or one moment earlier or later, would a world of life have been created that would never include you (or anyone who exists right now, or anyone who would have existed right now had Augustus Caesar tripped on stump one day rather than, as actually happened, not, or anyone who would have existed right now had Augustus Caesar never existed but a bunch of other people in Rome did) as one of its organisms? Did the potential for you inhere in that particular thing happening at that one instant, and no other?

You may wish to draw the line here, and say that you could still have come into existence even if the matter in the primordial soup had been moving about differently. It may feel satisfying to think that even if that matter had moved about differently, history still could have moved along in a similar manner and discharged your existence when it happened. You can believe this. But you have to ask yourself, why believe it? You must be imagining that there is something special about the time and place and location of the creation of your gametes that dictates that those are essentially the circumstances under which you would come into existence.

            The belief we are led to is that the potential for you inhered in the universe at the very start, but it only inhered in one single chain of events among a Vastly large number of possible chains of events (or, perhaps, infinite). The natural question is, why is that chain of events wedded to you coming into existence?

And if all of this is so, if the potential for your existence has been inhering in the universe and in this matter all along, passed down from generation to generation, there is another question: why has it finally led to you coming into existence now? Why not before or after? Was there some sort of time stamp on it? We have to believe that that potential for you coming into existence had to be carried forward throughout all of history, only to finally be discharged at the moment it was, in the formation of gametes at a particular time but no other, in a particular manner but no other, of a particular set of matter but not another, and into a particular structure but no other. For some reason. This seems like an exceedingly odd belief. Especially for a materialist.

iv. A Very Special Perfect Doppelgänger

I always feel like we should all pause to take a breath at this point. I always feel a little exhilarated when I consider the Vastness of all the possible universes and my place in it. But before I get to the conclusions, I have to bring us back down to earth for another puzzle.

There is an important question about PD I’ve been holding back up until now, and this talk of parentage seems an appropriate place to finally bring it up. I asked you in in PD to imagine someone you are very close and intimate with being a perfect doppelgänger, such as a friend or spouse. I deliberately did not suggest an obvious intimate relation, one of your parents, because this poses a special question of its own.

Imagine your mother in the perfect doppelgänger thought experiment, where she rather than you were the A gametes. Then imagine that the B gametes on the spaceship were selected, rather than the A gametes that produced your mother in this universe, and the B person grew and lived a life exactly like the one your mother did. So rather than your mother existing and living the life she has, her perfect doppelgänger did instead. The question arises, then: would you exist? Under the stipulations of PD, she would have produced a child with your father, your actual father, not his perfect doppelgänger, in exactly the manner that they produced you, from exactly identical gametes, your father’s being the actual sperm that produced you and your mother’s perfect doppelgänger’s ovum being…well, that’s the question. Is it the same ovum? Would you come into existence in this situation? Is there youness inhering in that ovum?

The most likely answer appears to be no, if we assume the standard belief, that the Gamete-Dependence Claim is true. Your mother’s perfect doppelgänger is a different person than your mother, as surely as if both her and your mother had come into existence and lived side-by-side. You could not have come into existence from anyone but your mother. In which case, your mother’s perfect doppelgänger could give rise to children who are perfect doppelgängers of you and your siblings, and you and your sibling’s children would then give birth perfect doppelgängers of the children you have or will have, and their children, on down the line, until the entirety of humanity becomes perfect doppelgängers of the people that will actually exist in this universe in which your actual mother and you both exist.

And we can switch this to the past tense to make it really vivid, and make one of your distant ancestors a perfect doppelgänger instead. If you go back far enough, you will come to someone who is a distant ancestor of all of humanity in the present day. We can take this person’s gametes out onto a spaceship, and so imagine the entire earth being physically exactly as it is today, except that no one who exists now exists, or will ever exist. It is simply perfect doppelgängers of everyone throughout the world.

But this “no” is such an odd answer. Why wouldn’t you come into existence from your mother’s perfect doppelgänger? The formation of that ovum and its subsequent career is identical to what it was in this world. Same atoms, same processes, same time, same location, same structure, same everything. Is that numerical identity, or merely qualitative identity? A perfect doppelgänger is only qualitatively identical to the “original” person, but what about a perfect doppelgänger’s children? In the example of your mother, the only difference is “who” the person is “inside” of that collection of atoms that makes up a human being at that point in time and space. How could that affect whether you, or someone a million years from now, comes into existence?

(And, calling back to the brain-dependence claim I mentioned above, wouldn’t it truly be the same brain in that case? Yet, this belief causes the trouble I mentioned above: you’d have to believe you wouldn’t exist had your zygote precursor in our world begun making a brain in a different location or of different matter than it actually did.)

This question, I find, is exceptionally powerful in isolating the paradoxical intuition we have about our own existence, the strangeness that it should come into being at this time and place and with this matter and structure and process of creation. It is perhaps the best question to come out of PD, the one that stabs straight into the heart of the mystery of our own existence. Here we have a situation even more perfect than PD, where all physical facts relating even to your own creation are exactly the same as in the actual universe A that created you, and yet we still have a question, would you come into existence here? Giving a “yes” answer forces the question “why?” and a “no” answer forces the question “why not?”, and this thereby distills the very essence of what I’m driving at: there is a physical object that either does or does not bring you into existence. Whether it does or does not has no basis in any physical fact. And so we can see clearly that both of those questions—why or why not—are just as valid for the actual circumstances of your coming or not coming into existence as they are for this possible scenario of your mother being a perfect doppelgänger. (Even if you are not grasping this fully right now, run this thought through your head at odd hours and see if some of that strange existential vertigo doesn’t creep up on you at an unexpected moment.)

And if PD is genuinely physically possible, then this is a real question, which must have an answer. It is not like one of the strange imagined cases of personal identity that Parfit gives, for which questions must be empty, or DS, for which we may decide the questions are empty. There is no reason to think this question is empty, because this is not a case of intermediate physical facts.

And even if PD is not genuinely a physical possibility, I still feel this is a question which should have an answer. Because the minute physical differences that may have to remain between universe A and universe B due to the laws of physics aren’t the smoking gun we’re looking for anyway. They don’t bring any clarity to the question of why I exist as one person rather than another, or now rather than another time, or not at all.[30]

v. Conclusions From Gamete Identity

This is my conclusion: Neither gametes nor any of the essential properties of gametes, including DNA and parentage, explain why you exist, either separately or all together. They do not bring any clarity to the question “why do I exist?”. You can ask this question, and it’s a good question, but usually someone will answer by appealing to one or more of these three conditions of DNA, gametes, and parentage. But none of these conditions, either individually or in combination, function as an explanation for why you exist. (And, as a consequence, neither does “evolution”.)

Pointing at gametes and saying “you exist because these existed” is no better than someone just pointing at your body and saying “you exist because this exists.” Most people who got the latter kind of answer would consider it to not be addressing the question. And yet, when we get down to gametes and DNA, many of these same people suddenly come to accept it as a profound answer where our body was not, just because they are smaller, or the last thing we come to as we trace backward down the chain. (Again, much like a homunculus.) But it’s not a profound answer. Pointing at gametes is no more profound or deep than pointing at a whole human body. Gametes and DNA are just an answer to the question “why does this exist” when someone is pointing at your body, and so if pointing at your body is not an answer, then neither are gametes and DNA. There is no obvious link between any DNA or gametes or parentage and your coming into existence. We can clearly conceive of all of those facts obtaining and you still not existing; there could be an infinite number of gametes identical to the A gametes wherein none of them caused you to exist, or we can conceive of the universe could having gone exactly as it has, and you not come into existence. All any of those factors explain is why a person of your genetic makeup and parentage came into being at a certain time. They don’t explain why that person is you rather than not, or why you exist now rather than don’t exist now. And it is worth reflecting on the fact that so many people are satisfied with them as explanations of their own existence, when they are no such thing.

            That takes care of one belief. But, as I said, perhaps not every materialist considers gametes and these properties of gametes to be explanations. Perhaps they only consider them to be necessary conditions. That no other conditions but these would have brought you into existence. How does this belief fare?

            It could be true. But we should ask what the basis is for our believing it, in the absence of any explanation. We do have the empirical fact at our disposal that these conditions did obtain and you do exist now as the resulting person. But we don’t know that they had to, or if they did, why they had to. We don’t know that no other conditions would have brought you into existence. All we know for certain is that this was at least one way to bring you into existence. We don’t have any counterfactual cases to compare this fact to; no cases where these conditions did not obtain, at this point in time in the history of the universe, at least, to then check whether you exist or not in those cases. (In fact, we have exactly the same evidence as this to support the claim that you wouldn’t exist if the life of the human being you currently call yourself had gone differently.) It seems that this would be helpful in ascertaining whether certain conditions are necessary, if we want to believe so certainly in them. Of course, it would be impossible to obtain such information; not only can we not run history several times to see what exists in different counterfactual situations, even if we could we would be unable to answer the question of whether you (or I, or anyone) existed in those situations or not. Neither you nor any other person could answer such a question. It’s impossible in principle. And so, if that really were all we had to support the belief that these were necessary conditions, I think we would have to wonder why we are so certain of it.

            But of course that’s not the only reason. I brought it up first because I think most people have never considered that weakness in our reasons for believing the gamete-dependence claim. But I have been quite clear all along of another reason why people are certain of the gamete-dependence claim: If you say you would have been another human being in a counterfactual history, then you have to contend with the possibility of that other human being existing alongside the human being you are now. And then who would you be? And who would the other person be if the human being you are now had never existed? This is the fact of compossibility, that you and a person from any other possible or actual set of gametes could coexist, and it seems incontrovertible, because those questions seem unanswerable. And this is therefore the best evidence we have for believing in the gamete-dependence claim.

            Yet, the fact of compossibility provides no answer to the question of why you exist. No explanation for it. So we are at an impasse…

4. The Original End To My Philosophizing:A Mysterious Non-Materialism

            These are the insights (minus the discussion of indexicality) I had in the first decade of the 2000s that led to my study of philosophy. I didn’t have much in the way of words for them then, but the basic intuitions were there. Originally, I thought that the point we have reached now would be the end of my essay or book or whatever on the topic. The conclusion I reached was: existence is a mystery. Evolution teaches us about why human beings exist, but why I should be one of them is a mystery. These questions have no answers.

            But I wasn’t really seeking an answer to the question of what caused me to come into existence. My motivation for making that inquiry at all was something much more important to me: death. I wanted a solution to the problem of death; I wanted to not be afraid to die. This was to be my epigrammatic takeaway:

How do I know I will cease to exist when I die, when I don’t know what caused me to come into existence in the first place?

A more precise way to put it: How do I know the end of this brain and body will be the end of my existence if I don’t know why this brain and body brought me into existence in the first place?

It’s a good question. If this was really all we had, existence would be a mystery still, even after evolution explained why human beings exist. And the supposed certain cold hard fact of materialism that we simply cease to exist when we die doesn’t seem so certain.

I took comfort in this, in the possibility that the mystery provided. It was a sort of tentative non-materialism. Maybe there really is a soul, I thought. It seems like that was the sort of thing I had discovered with this investigation. In fact this is what I told some of my friends at the time: that I had discovered the soul. “I mean, I’m not saying for sure that there is a soul, because I’m well aware of the problems with the idea, but… well, just look at that question again.” Existence is truly a mystery, and what could be more mysterious than the soul?

In fact, if I’m being really honest, I think this work started out as a search for the soul. The intuition that I thought Dawkins’ explanations of evolution didn’t cover, I thought that must be the soul. I just had to find it. PD was my attempt to find it. I thought with PD I had isolated it, the thing that was there that was above and beyond matter, that materialism couldn’t explain, that proved materialism wrong. For a long time, this is the work I thought I was writing.

But then, in late 2013, a thought occurred to me—which I present in Part II as TMT—that completely changed my view of what was possible for a materialist to believe, and everything quickly came together into a theory with an actual conclusion. From that point on, my pace of study and writing increased many times over from what I had been doing the previous seven years.

And so my conclusion is not that existence is a mystery, or that we must be souls. It is something altogether more concrete, that I’ll come to through Parts III and IV.

You can take Part I on its own in another way though: as a statement of a problem. Specifically, I think there is a problem with our current theories of existence, either the ones we have stated explicitly or the ones that we tacitly accept. Alternately, you could say there is a problem with our current conception of materialism. Or, you could say that the way we think about materialism and the way we think about our personal existence are incompatible. Any of these will do, though the actual statement of the problem is the entirety of Part I, and these should not be taken as substitutes.

What follows from Part III onward is my solution to this problem, which I think is correct. But even if you do not, the problem still exists, and needs to be reckoned with. If you don’t like my solution, then I think another will have to be found.

I’ll return to complete my conclusion of Part I from the previous section, to let you know the direction I’ll be taking with my solution:

Compossibility is perhaps the fact that most motivates our belief that the conditions that brought us into existence in the present were the necessary conditions for us to come into existence. Compossibility is when you arrive at a candidate in an alternate world that you think could have been you in that alternate world, but then you must reflect that that very same candidate could have existed in this world you are in now. This is probably the strongest reason—the only reason I know of in fact—we have blocking disbelief in the gamete-dependence claim. If one could get around the problem of compossibility, one could get around the gamete-dependence claim, and just maybe solve all of these mysteries of existence I’ve been bringing up.

This is one of several tasks I will take up in Part III. First, in Part II, I will take a different avenue to exploring and clarifying what we mean by personal existence. The conceptual apparatus I construct there will be very useful to the argument in Part III and beyond.

Part II. What Do We Want?

  1. What Do We Really Want? Unattaching From The Content Of Our Lives

            None of the contents of my mind is going to survive my death. My memories, desires, intentions, likes, dislikes, loves, hates, hopes, dreams, anxieties, beliefs, aptitudes, skills, all of these things will disappear when I die. Unlike most of the things I’ve claimed so far in this essay, we have empirical evidence of this. There are numerous documented cases where damage to a specific part of a person’s brain, either by disease or injury, caused one or more of these things to change or disappear, while the person remained alive, conscious, functioning otherwise normally, with other faculties still in operation and other content remaining. We thereby have ample evidence that these things are embodied in the brain, and can often even roughly locate where they are in the brain. Further, it is universally acknowledged that this brain crumbles to dust when a person dies. This happens 100% of the time, in the absence of special preservation. Add these two facts up, and the inescapable conclusion is that all of this content of person’s life crumbles to dust with the brain that embodied it.[31]

            I first became convinced of this fact, against my will, reading Oliver Sacks’ The Man Who Mistook His Wife For A Hat. Sacks describes case studies of so many of the things that we take for granted as essential aspects of ourselves, disappearing in individuals when their brain is damaged. This includes even things that were previously invisible to us as special faculties, like the ability to recognize human faces, or, indeed, the ability to recognize that one’s wife is not in fact a hat. Also demanding consideration is the foundational case of these types of studies, Phineas Gage, in which a righteous and responsible man, surely destined for heaven, became a psychological mess and what some would consider a not-properly repentant sinner after a steel rod took out part of his brain in an explosion while working on the railroad. This is especially powerful because the belief in the dominant Christian tradition of the time and place, mid-19th century America, was that your behavior and attitudes on earth determined where you went in the afterlife, and that you carried those characteristics with you to the afterlife. In other words, that there are characteristics that are an inseparable part of who you are, of your soul, and that you earn eternal punishment or reward because of these. If an accident to your body on earth that is beyond your control can dictate what these characteristics are, this is problematic for the idea of just deserts, especially eternal ones. Gage pops up everywhere in the literature, but Antonio Damasio describes and analyzes the case well in Descartes’ Error. Damasio also tells a fascinating story of a modern man who lost the ability to feel any emotion, and thereby the ability to make any decisions.

            These stories struck me hard because my Christian upbringing conditioned me to expect from my very first thoughts about it that everything that occurred in my life would last and would matter for all eternity. Since I’d generally been a good boy, with faith when that became required, that had always been a comforting thought. And it’s absence when I decided I no longer believed was terrifying.

            This attachment to the specific content of our own life is a peculiar kind of tunnel vision though. The truth is, most of us don’t care about the specific content of our lives nearly as much as we think we do. We can imagine having lived a completely different life than the one we have lived, and know that we could easily be just as happy with that life as the one we have now, and could probably have had a life we were even more happy with. If I’d been adopted by a nice French couple when I was born, I think I’d be doing pretty well right now. (It’s a bias of my current self; I rather like France.) Or, if at birth some roguish but kindly pirates had kidnapped me and I’d been whisked away to an isolated Polynesian island and taught to live self-sufficiently in a tropical paradise, I could be existing there right now at this moment, and I rather think I might be quite happy with it. Ecstatic even. Amazed at my good fortune. In other words, we freely and happily acknowledge that the content of our life is contingent anyway; it generally does not frighten us to think that it could have all been quite different, and that the current content of our life might never have come to be. We know the content of our life is not an immutable essence of our self. So why would it be important to us that this contingent content last for eternity in our subjective memory? Why does the loss of this content, after the fact, frighten us?

            There are some reasons for this, of course. We’ve put an awful lot of hard work and heartache into building up all of this content, for one, and it’s depressing to think that it was all for naught, in the grand scheme of things. But then, it is also a well-known fact that a large amount of the content of our life is lost while we are still living it. A tiny percentage of the specific memories we had when we were ten years old remain with us now, and an even tinier percentage of everything that happened to us in that eleventh year of our life remains with us. The contents of our mind disappear bit by bit even while we are still living a life with that mind. We mourn this only a small amount, and infrequently. We are already well aware of how transient the content that we count as our “self” is, yet we still continue mostly satisfied lives. Dissatisfaction only becomes deep and persistent when the losses are drastic and rapid, such as happens with Alzheimer’s in old age.

            The content of our life does matter to us, and it is acceptable for it to matter to us. But it matters less than we think it does.

  1. What We Have Right Now: Defense of a Partial Cartesianism

a. The Actual Referent of “I Exist”

It’s a significant fact that we don’t undergo all this philosophizing about personal existence just to get to the bottom of it, out of curiosity, in the same way we might, say, be curious about what is true and false about prime numbers. Some topics in philosophy are probably like that, such as the transworld identity of inanimate objects. And there is surely some of that motivation in the exploration of personal existence, and some might claim that is all the motivation they have to it, but likely for most people there is more to it. What keeps such a large number of people coming back to the questions over and over even though answers are so difficult to obtain and/or unsatisfying is that it matters to us what the answers are. There are answers we want out of it, conclusions we want to reach. Namely, we want to exist, and don’t want to not exist.

            The reason I say this is not to point out how we are influenced in our philosophizing by the conclusions we want to reach, though this is of course an important point to keep in mind with all philosophizing, both our own and others. For what it’s worth, I hope the conclusions about losing the content of our lives at death I mentioned above at least demonstrate that I personally have some capacity to be swayed by reasoning that reaches conclusions antithetical to my desires. (I’d like to think I have rather a lot, actually, and would be glad to put my history of belief on trial. My reactions to both Dawkins and Parfit are further pieces of evidence.)

But the actual reason I’m talking about what we want has nothing whatsoever to do with this. Rather, it’s to try to discover something important about the actual referent of the term “existence” or “I exist”. What is it we are referring to when we say this? I’ve already spent a lot of time on this question and used several different methods to try to get at it, and now I want to try another. Sections a. and b. here get rather philosophically wonkish and abstract, and if you get lost, you’re welcome to jump ahead to section c.

Let me start by asking, what are the characteristics of this thing we are referring to when we say “I exist”? The characteristics, that is, besides anything that could be categorized as content. We already know that content is one thing, personal existence another. So what does “I exist” refer to, outside of content?

One characteristic, as I said, is that it is something which we want. It is not neutral. And a second important characteristic follows from analyzing this first one. This want is a specific type of want: it’s not something people are hoping to gain or acquire at a later date. What people fear about it is not that they might never obtain it. The fear people have about it, and the only fear they have about it, is that they will lose it, and in particular lose it in death. And so, we should believe that this existence, “I exist”, is a thing which each one of us already has.

This might sound glib, if it is taken merely as the statement of a premise—that  we aren’t afraid of not gaining existence, but of losing it—and a conclusion—therefore, we must already have existence—without reflecting on the underlying concept. But what I’m trying to get at with these words is a pre-verbal, pre-philosophical idea, the idea that people had in mind before they invented the word “existence” (or at least before they thought to apply it to themselves) in whatever language first had such a word. It is what a pre-language ancestor to modern humans might have been thinking of that they were trying to preserve by avoiding dying, or when they grieved over death or that they feared that they’d lose in the possibility of death. It was simply this thing we have right now that we want to keep.

Descartes famously made the argument for what is now called the Cartesian intuition, which is that the one thing it doesn’t make sense for me to doubt is my own existence. Or the one thing you could not be imagining or be being deceived about is that you exist. (Neither of these are Descartes’ actual formulation of it, but they get at the idea.) Readers will recognize that this is exactly what I’m driving at here. Readers will also know that if there’s one conclusion in all of metaphysics that is considered to be on solid ground, it’s that Descartes intuition doesn’t stand up. This was taken to be so by critical philosophers right when Descartes made it, and has been probably the most respectable belief about it ever since.

But I think this wholesale rejection of the intuition is an error. The correct rejection of the Cartesian intuition is only a partial one. Descartes made claims that several things must follow from this intuition, such as that this existence must therefore be an actual thing, and that being an unextended thing (taking up no space) it therefore must be non-material, a soul, and that this must be the basis for us taking someone to be the same person at different times, which is the idea of personal identity through time. The conclusions are all widely rejected, and I reject them as well. But it is a mistake, a confusion, to throw out the original intuition with them.

I think this goes back to people not being clear what they are talking about, what they are actually referring to, when they talk about existence. My distinction between personal existence and content goes a long way to solving this, I think. We could leave it at that, in fact, and move on to Part III, which picks the argument up right here it left off in Part I. But there is this essential point I want to really get down about personal existence, here and in the last section of Part II, to really put us on conceptually solid ground: the words “I exist” must by definition refer to something we already have, and that we want to keep, whatever that thing is, and whatever it’s actual ontological status. “I exist” is a thing we want to be obtaining, and the present actually is the state of affairs we’re satisfied with in that regard. So “I exist” by definition refers to something about how things are right now, at least.

If you try to define “I exist” or “personal existence” as one thing or another (such as any of the list of Descartes’ conclusions above), and then show that whichever of these things you are examining does not in fact exist or does not in fact hold, you have not shown that nobody exists, that “I exist” doesn’t refer to anything. You have just changed the subject. Your argument for why this other thing doesn’t exist or hold may be completely correct and very useful, but it doesn’t touch the actual referent of “I exist”. The actual referent is whatever it is I want out of existence besides content that obtains at this very moment.

I’m once again trying to get at an inchoate perplexity here, but rather than try to make it concrete as I did with PD, I’m using another inchoate intuition to try to make this one clear. There is the idea under the surface I’m trying to get at, about what we must in fact be referring to when we think of our own existence, and how this thing must actually obtain. Formal argumentation, and the attempt to put it into words as I’m doing, can obscure this central fact. But I feel that any true reflection, away from formal argumentation, but just the sort of thoughts that might float into one’s head when philosophically pondering one’s own existence while walking down the street, will see that it’s right that the words “I exist” must by definition refer to something we already have, and that we want to keep, whatever that thing is. (Or at least, I’ve found much repeated affirmation of this proposition under these conditions.) In other words, if we have anything at all, then that is the thing that “I exist” refers to. By definition, the referent of “I exist” moves until it settles on the thing we have.

And so I want to propose a new definition for “I exist”. From here on out, when I say “existence” or “personal existence” or “I exist”, the referent of these terms is: the thing we want that we have right now. Or, the thing we want that obtains at this moment. (Again: besides content of course.)

b. The Counter-Argument: You Are Only Imagining That You Exist

The counter-argument to this claim, the one Descartes argues against from the start, is: couldn’t people just be imagining that they have it, this “existence”? Couldn’t this be an illusion? This is the way it is framed by a lot of people, in fact: “Existence is an illusion.”

My counter-question is, what could that mean, to imagine existing, at this moment at least, but not to actually exist? What would “actually” mean in that instance? “Actual” according to what? “Existence”, at this moment, seems the kind of thing that it would be incoherent to claim you could only be imagining it obtaining, but it not obtaining in “reality”. (I realize I am only repeating myself, and Descartes.) This claim would seem to offend what is necessarily the definition of reality. (The referent of “reality” should also rightly shift if you try to define it away, I think.)

I’ll try to make my point clearer with some arguments by analogy. As is usual with such things, if you find these analogies unhelpful, I hope they won’t be too distracting. It is not essential that the analogies fit perfectly. The intention is to jog in your own mind something about the concept of existence, but if they don’t do that, you can safely move on anyway.[32]

Let’s say I have a love with a woman, a love I don’t want to lose. What does it mean to “have a love”? Roughly, probably just a state that obtains in my brain that is a combination of my feelings for a woman and my imagination of her feelings for me. Whether I am imagining something close to her actual feelings for me, or am completely wrong about them, to me her feelings for me are just something in my mind, so either way it’s my imagination; the real question is whether I am imagining her feelings correctly or incorrectly, not whether I’m imagining them at all.

 So let’s say that, even though we are dating and it appears I have this love, it turns out she doesn’t actually love me, and never did, even from the start. She was with me for an ulterior motive, and just tricked me into thinking we had a love together. So this love is an illusion. Even while I think I have it, I don’t really have it.

So, the argument might go, I can’t actually lose it, because I never had it, it was never there, it was an illusion. But is it therefore meaningless for me to say, while I still think I have this love, that I don’t want to lose it? What is the “it” in reference to there? I think it’s to a true love, but it’s actually to a false love, to an illusion of love. But whatever it is, it’s still definitely something I want, and something I don’t want to lose. And it’s something I genuinely can lose, by finding out her true feelings for me, so it must be in some important sense a real thing, and a real thing that I have. So if we switch the referent to “the thing I want”, rather than something like “love” which can have multiple interpretations and be said to obtain or not obtain in reality, then “it” by definition becomes whatever it is that obtains in the moment that I like and that I want to hold onto at that moment. And what I actually do have, what actually is making me happy, is the illusion of love. The thing that will actually make me sad is losing the illusion. But it doesn’t mean I actually have nothing. I have the illusion, and it is coherent for me to want to keep it.

So if I say “I want to be existing now, and to continue to exist”, and you claim that it is an illusion, we could grant that the actual ontology of this is just that I want to have an illusion of existing now and to continue to have this illusion of existence. So, in a meta sort of way, I can say, “Okay, the thing I want to have then is the illusion of existing. And, by the way, this is actually what I will mean from now when I say ‘I exist’. It is, in a sense, what I’ve meant all along by “I exist”, if this is the actual ontology of existence. So I’m just going to use the word ‘existence’ as a stand-in for ‘illusion of existence’ from now on.” Therefore, the word “existence” does have a referent after all, and it is something I can want to keep. (We have a great many possible realities in which it doesn’t obtain, and a great many possible times in which it doesn’t obtain, to contrast it to.) It doesn’t matter what the ontology of it is, it’s just a thing I want and want to keep. And if I remain unaware that my own existence is an illusion, I will just want to keep whatever it is I have.

In the case of love, though the experience of having the love could similarly be exactly the same whether it is an illusion or a reality, there is an objective fact that can decide whether it is an illusion or not, namely, how the woman actually feels about me. This gives the term “illusion” a definite meaning in this case. The term is doing some work here. But in the case of existing, there is no objective fact to appeal to to decide whether it is real or an illusion. And so, the two collapse into meaning the same thing. The experience of existing is also exactly the same as actually existing, but there are no further facts to appeal to to distinguish them. There is no way to define what “existing” means outside of my experience of it. And so to call it an illusion is meaningless. What is the difference between actually existing in this moment and only having the illusion that I exist? If I had this illusion of existing and kept it for all eternity, how would that be different from actually existing? And not just in appearance, but fundamentally in reality? It is in this way that the referent of “exist” always slips to something I actually have, no matter how I try to define it away.

            I am using a form of content, “the feeling of being in love”, as an analogy to the thing I have otherwise conceptually separated from content, personal existence or “I exist”. So it is imperfect. “I exist” is an incomparable concept; there is nothing else like it. But I’ll give you another example from content, and perhaps this one is even closer, because it doesn’t necessarily involve another person: pain.[33]

What is the difference between having an actual pain and an imagined pain? “Imagined pain” certainly has an objective definition, as one that has no physiological basis anywhere in a body outside of the brain, and is not an indication of anything wrong with any part of your body, but is only a (mis-)firing of neurons. But surely if you are feeling a pain, whatever the cause, then that pain obtains, and it is not true to say you don’t have it, even if you are imagining it. It is pain. Our phenomenological experience of pain fixes the reference of the word. If another organism, similar or alien to earth organisms that feel pain, had the physiological characteristics of pain in its body and its brain, but did not “feel pain”, it wouldn’t count as pain (whether or not there is in principle any way of detecting whether it “feels pain”). It would be something different. And so, you can say, “I want this pain to stop”, and someone can tell you, “you are only imagining it anyway so it doesn’t matter if it stops or not”, or if they’re being more careful, “it doesn’t actually exist so it can neither stop nor continue.” The only correct response to this is, well, whatever it is that’s obtaining right now that I don’t like, I want it to stop obtaining. I want to subtract that, and maybe just that, from what is obtaining at this moment in the universe.

What would be the difference between having the illusion of pain for eternity and actually being in pain for eternity?

            So, again, if you want to say I’m only imagining existing, then I want to keep imagining it; if “imagining existing” is what obtains right now, then that’s what I want to keep obtaining, and that’s the state I’m referring to when I say “exist”. The referent will always just slip back to whatever it is that actually obtains right now. That is the state of affairs I’m satisfied with, and that is what I don’t want to lose, and that is therefore by definition what “I exist” refers to. I want nothing more than this. It seems impossible to argue with that.

c. The Real Meaning of the Claim That We Don’t Exist

Probably one has never needed to be a Cartesian anyway to agree that we exist at this moment. Jim Stone writes as a self-described eliminative materialist, which, according to Simon Blackburn, is a materialist who believes that the terms we use to describe the mind, such as “mind”, “consciousness”, “self”, and “qualia”, are “sufficiently infected with error for it to be better to abandon them than to continue trying to give coherent theories of their use.”[34] In a paper called “Parfit and the Buddha: Why There Are No People”, Stone criticizes Parfit for still believing that “person” has a referent in his (Parfit’s) argument for the reductionist view of personal identity (from Part III of Reasons and Persons, the same text that so influenced me and that I laregely accept). Stone states that “[I]f reductionism is true there are no persons. Either persons are extra, or there are no persons… Reductionism, which affirms the existence of persons while denying that they are something extra, is incoherent.” By “extra” Stone and Parfit mean something like a soul for example. In other words, Stone believes that unless there is a soul underlying a person’s existence, then the concept of a person as an entity that persists through time, for example an entity that can be punished for past offenses and have hopes for its own future, is incoherent.

            I agree to a large extent with what Stone was trying to accomplish in this paper. His diagnosis of the problem of Parfit still believing that the term “person” still refers to something after Parfit’s reductionist conclusions about personal identity, I think, relates to my problems with Parfit’s affirming the gamete-dependence claim after his statement of the reductionist conclusions about personal identity. I don’t think the term “person” is useless, but I do agree it has meanings that need to be excised for careful discussions.

But this isn’t my reason for bringing him up. It’s what Stone gives as the correct view that I find telling: “To put the matter paradoxically, we need to face the fact that we don’t exist. There is simply nothing in nature for us to be.” There is only matter, and matter is in flux. Yet Stone finishes his conclusions with this:

Probably we are very transient: if we exist at all we come and go in a moment. Like all processes in nature, animal lives are comprised of empty phenomena rolling on, except in this case the momentary phenomena tend to take themselves very seriously. I suspect that this is the truth about us and that it is the inevitable consequence of science and empiricism, but how one comes to live with the truth I don’t know.[35]

Stone says “we don’t exist”, and then says “if we exist at all we come and go in a moment.” I think his backtracking about whether or not we exist is a great example of how unclear philosophers can be sometimes when speaking about existence (keeping in mind the praise I otherwise give for his views and writing). Stone insists emphatically that no one exists, knowing that people will resist this assertion, but that this resistance is not for good reason, it’s just because it makes us uncomfortable: it’s a fact “we need to face”. No denial of this fact is acceptable. Any denial is arguing from desire to believe, not from solid reasons. This is the reason for his bluntness about it. But then he immediately does what he has forbidden: he admits that actually we might exist, if only for a moment. And this is what I mean when I say that people who claim no one exists don’t really mean it. They are overstating the conclusion, claiming to be true more than they themselves really believe. I won’t say this isn’t understandable, when trying to dislodge deeply entrenched ways of thinking or shake people loose from “dogmatic slumbers”, as it were, but one must be careful to not take the words used for effect and move them over into your actual ontology.

            I think Stone provides a clue as to his motivation, and it is the same as the motivation of a great many other philosophers and scientists and other such people who have been trying to shake humanity out of its belief in gods and souls and to accept the materialist position. Stone says about his beliefs, “how one comes to live with the truth I don’t know.” There is a sense that the truth is unpleasant, that really understanding existence is terrifying, opens up an abyss beneath us. And I think this can lead a person to think, perhaps subconsciously, that in fact unpleasantness is evidence—proof even, or at least an acid test—of rigor in your argument, because it shows your lack of sentimentality and desire clouding your judgment.

Personally, I think I bought this as well. I went from being a religious believer in souls to a materialist, having found myself always convinced by the sort of reductive arguments that Dawkins and Parfit offered, no matter how much I didn’t want to be, and so I began to expect that all the truths one discovers about one’s own existence are going to be unpleasant. I shared the reaction that Dawkins documents from readers of The Selfish Gene, great examples of just how unpleasant the truth can be:

A foreign publisher of my first book [The Selfish Gene] confessed that he could not sleep for three nights after reading it, so troubled was he by what he saw as its cold, bleak message. Others have asked how I can bear to get up in the morning. A teacher from a distant country wrote to me reproachfully that a pupil had come to him in tears after reading the same book, because it had persuaded her that life was empty and purposeless. He advised her not to show the book to any of her friends, for fear contaminating them with the same nihilistic pessimism.

And in the introduction to the 30th Anniversary Edition of The Selfish Gene, he quotes another reader’s response:

Fascinating, but at times I wish I could unread it…on one level, I can share in the sense of wonder Dawkins so evidently sees in the workings-out of such complex processes…But at the same time, I largely blame The Selfish Gene for a series of bouts of depression I suffered from for more than a decade…Never sure of my spiritual outlook on life, but trying to find something deeper—trying to believe, but not quite being able to—I found that this book just about blew away any vague ideas I had along these lines, and prevented them from coalescing any further. This created quite a strong personal crisis for me some years ago.

I suspect that many readers of Part 3 of Parfit’s Reasons and Persons also had this reaction. (I did.) It is, in other words, understood that reality, if we really face it, is an existential abyss. We only survive day to day by focusing on pleasant fictions.

If ever closer inspection of reality subtracts more and more of what we want from the universe, then (the usually unexamined assumption goes) pure reality probably or necessarily subtracts everything we want from the universe, and the belief is that if we seek truth and not just to feel good, then we must just stoically accept this. One reason I belabored the argument that I do exist right now in this moment was to bring this prejudice to light. Many would have us subtract our own existence in this moment as well, and I think by focusing on the details of arguments we often do subtract it, perhaps without even noticing it. At least, we subtract it in one way, by telling ourselves it is not allowed to believe it, because we think that to be unwilling to do this would be unrigorous sentimentalism. But we do not subtract it another way, because we do in fact continue to believe it, continue to believe we exist, even if we force ourselves to form statements that assert the opposite.

But we have primitive reasons to believe that we exist and a mere argument shouldn’t be able to so easily dislodge it. It simply cannot be subtracted, regardless of whether we want to or not, and to assert this is not (necessarily) just a sign of obstinate sentimental attachment to existence. It is, for the reasons I gave, clear thinking.

            There is a broader point here. It seems that many philosophers, including Stone and Parfit, apply conclusions about concepts like “person” and “identity” to the concept of “existence” without giving any notice that they are introducing a new term, as though they obviously all mean the same thing. It certainly has been an acceptable assumption that they mean the same thing for a very long time, so this is not a criticism of them personally. But I feel that this is an underlying ambiguity that should be exposed and clarified. To put it into the terms I’m using here, the concept of personal identity includes the concepts of both content and existence, yet the answers to the questions of whether content obtains in certain counterfactual situations and whether existence obtains in certain counterfactual situations are different, and the methods we use and the factors we take into consideration in trying to answer these questions are different as well. This can sometimes lead to two people being unaware that they are each discussing different subjects when the topic is something like personal identity.

I had long suspected this, and was emboldened in the belief when I came across the first corroboration of my suspicion in Mark Johnston’s Surviving Death, in which he clarifies the distinction between personal identity and self identity. He believes that while personal identity is important for things like justice and reward, self identity is what we should have been thinking about all along when thinking about existence and death. I think this is correct, or at least the right direction to go, though I’ve been avoiding the term “self”. Though this book was published in 2010, I have only recently (spring 2015) become aware of it, and so its content hasn’t greatly influenced my writing of this essay, though if I had read it earlier it might have.

At any rate, I have eliminative materialist Jim Stone (or at least 1985 eliminative materialist Jim Stone) on my side in the belief that it is acceptable to say “I exist at this moment at least”. I have something interesting to build on top of this.

  1. Transworld Material Transmigration (TMT)


            So you exist right now, at this very moment, at least.

            So let me take you through a thought exercise based on this, another chapter in the perfect doppelgänger saga. It’s a tangent from the main thread of my argument, and can be skipped, but I include it here because it was the first revelatory thought I had that eventually led to the new conclusions about my own existence that I now hold. It may provide such a bridge to you as well, and anyway I still find it intriguing.

            I’m calling it “the transworld material transmigration thought exercise” (perhaps it is not quite an “experiment”), or TMT for short. I know, that name is utterly ridiculous. Who do I think I am, Philip K. Dick? Immanuel Kant?[36] But I love it. TMT had a powerful effect on me when I first thought of it; I walked around for weeks in a sort of rapturous daze just thinking about what it meant. I realize that this admission will detract somewhat from my appearance of seriousness and perhaps from my trustworthiness; contrary to some popular belief, philosophy is not an ecstatic spiritual experience. But I did come down from that otherworldly plane eventually, and TMT still had me intrigued, even when just engaging my intellect. So, although I should probably consider a quasi-religious appellation like “transworld material transmigration” to be embarrassingly pretentious, even after several years of sober reflection I have been unable to shake the feeling that it should get a lofty name, so I’m going with it.

TMT rests on the possibly controversial premise that, in PD, it is possible for person B to be absolutely physically identical with person A in every possible way, down to the smallest subatomic details, in actual reality and not just our imaginations. (Recall that on the strictest telling of PD, even the same atoms come to earth in the gametes in both universes; this is helpful but not absolutely necessary to suppose here as well.) This means that on earth and in almost all of the universe, all physical details are identical between universe A and universe B during the stretch of time that person A or B exists and forever after. And if a black hole can cause true information death, then if the space station falls into the black hole it is orbiting after the selected gametes are removed, it is possible for everything throughout the universe to be identical between universes A and B in all the time after that.

            TMT also trades on the notion that a materialist should find PD problematic for materialism, because on PD, even in two materially identical counterfactual portions of the same time and space, there can still be a difference, the difference of who exists there. I touched on that briefly in my conclusions for PD, and pointed out that though it seems reasonable to me, it is likely controversial, and I can take it or leave it. But TMT will make more sense of this belief.

Based on these two ideas, the thought exercise is this: Sit back and introspect on this moment, the very present point in time. Meditate upon your existence in this moment. You are here, now. The thing you want when you say “I exist” obtains right now. Enter this moment and notice that fact.

Note next all the facts that you have available at this exact point in time. Note everything you are seeing, hearing, smelling, feeling, and thinking. Just settle on those for awhile. Now imagine universe A. Recall though that universe A is the universe you are in right now. It is not a theoretical universe. It is not just a construct of a thought experiment. Universe A is, by definition, everything that actually is obtaining in this universe at this moment.[37] And that includes what you are doing right now. So, to “imagine” universe A, all you need to do is “imagine” exactly what reality is right now. Which isn’t imagining at all. It’s experiencing. So the act of imagining it would be like a boomerang. You prepare to throw your mind into some other reality, as in all cases of imagination, like for example imagining getting up and getting a drink of water right now. But instead, you find your mind comes right back to where it actually is right now. Not a bit of difference, because you are not imaging a different situation.

            Now believe in materialism; believe that there is no difference between universe A and universe B at this moment in time, here on earth at minimum and perhaps throughout the universe, because there is no physical difference, and the physical is all there is, so that means there is no difference whatsoever. Think about universe A again, which is all the facts obtaining right now; think, in other words, just about actual reality as it is at this moment.

            Now imagine universe B.

            Imagine that the B gametes had been selected instead of the A gametes. The A gametes, the gametes that produced you, were destroyed. Imagine therefore that universe B had obtained instead of universe A, and that it is right now the case that universe B is the reality instead of universe A. Throw your mind into that situation. Take a moment.

What are you imagining? What reality did you throw your mind into?

If you are doing it correctly, as a materialist, then you should just be imagining yourself, doing exactly what you are doing right now.

It would be proper to take a long pause right now, to consider this, but that’s not how writing works, so instead I’ll continue explaining.

There’s two ways you could be doing this.

One way would be, just as with universe A, to not be imagining anything, but just experiencing what you are experiencing right now, as the B universe. The reality of the B universe is just you experiencing what you are experiencing right now. Let me say that again, with proper emphasis: The reality of the B universe is just you experiencing what you are experiencing right now.

On the other hand, if you are thinking of it as a “there”, an alternate situation that requires imagination, then you should be imaging yourself there. This is what would be obtaining right now if universe B had obtained. You would be there, in universe B, as person B, just as you are person A, yourself, in our universe.

 Either way, you should not be looking at this world from the outside in your mind’s eye, or at person B from outside in your mind’s eye, as you would be if you were imagining a situation in which you don’t exist. You should be experiencing this person from the inside, just as you are now. You should be imagining this because if, on materialism, every fact is the same between the two universes in this place and time, then universe B would be truly indistinguishable from universe A in every fact, including your existence in it, in the exact situation it is in in universe A.

If you are imagining universe B and person B incorrectly, then you will be imagining someone else there, doing exactly what you are doing right now, and imagining yourself not existing. This would be doing it incorrectly because it would be adding an element to all the physical facts, a someone else that is not you to be experiencing all these things, and subtracting an element, you. Materialism says material is all there is, that it exhausts all the facts. Universe B is materially identical to universe A at this moment, including being in the same place—it is in other words not a materially identical universe of cosmology far out in space beyond our own observable universe. So under the rules of materialism, you are not allowed to imagine something missing from Universe B that is obtaining right now at this moment in Universe A. Universe A and Universe B are physically identical. And since physical matter is all there is, then what you are experiencing in universe A must be purely physical matter, including your personal experience of it. Therefore, when you imagine Universe B, you should be imagining it identically to the way you imagine Universe A. And this includes you sitting there, imagining it.

So this is TMT. (Now that it’s done, I’m embarrassed to type out the full name again.) If you feel at all moved by it, I recommend pausing to contemplate it for awhile.

What was important about it to me was this: it was the first time I’d ever found a logically sound reason to believe I could have been someone else in a material universe. So it hit me hard, and seemed quite profound. I’d like to think at least some other people would react the same way to it.

Further, I quickly realized that if I felt I should be person B in PD, then I should also be person B if person B had lived a different life, just as I would be person A if he (I) had lived a different life. (This is jumping ahead just slightly; more on this point in the next section.) And if this is the case, if I can find good materialist reasons to believe in my “jumping to” (or “transmigrating”) to a numerically different human being, and especially one that lived a different life than me, then what remains significant about the particular DNA of that human being? Why couldn’t I exist as a human being with different DNA? (Also jumping ahead, but these ideas were coming to me fast and furious, and added to the existential vertigo I experienced; more on this point in Part III.) All of these thoughts threw the concept of personal existence, my own existence, wide open for me.

But I do know that a few days after I thought of it, I discovered a problem in my formulation of it. You may have discovered it right away. I hate to give it up before giving you a few days to ponder, but again, such is the way writing works.

So here’s the problem: when thinking of TMT, I took for granted the way I originally envisaged PD, that for universe B the A gametes were destroyed. But the A gametes need not have been destroyed. They could have been kept alive, then joined, and the resulting person lived a long life, right up to the present and beyond. Perhaps he remained on the space station. What is the proper response to TMT in that situation? Clearly, I should imagine myself on the space station at this moment, as him, for all the many reasons I’ve already gone over multiple times so far, most particularly compossibility and tracing a physical structure through time and space.

So there is an incompatibility, the same one I told you was preventing you from believing that you would have been person B in the original PD.

But when I first thought of PD, it did not occur to me at all that there would be any reason whatsoever to think that I could under any circumstances be person B. That was the whole point of PD. I thought it was just a plain fact that the gamete-dependence claim was obviously true. And so my reasoning ended at Part I, as I said, merely affirming a mystery in the face of supposed materialistic certainty: I don’t know what caused me to exist, so I how can I know I will cease to exist when I die? But TMT, though the way I conceived of it was flawed, shook something loose in my conception of the my existence and the universe, and opened my eyes to new possibilities. I got a taste of this existence as “another human being”, so to speak, and I was hooked. When I discovered the flaw, it didn’t make me immediately repudiate TMT; I felt rather that a paradox was left, one that should be resolved. So my mind began working overtime to see if there was another way I could justify the intuition of TMT, and if could solve the paradox. I found ways to do both of these things, which is what I present in Parts III and IV.

Before I get to this, let me just get one final point out of the way first.

  1. What Else Can We Have?

I suppose I was a bit disingenuous before in claiming to be arguing for just the minimal conclusion that we at least exist at just this moment. I did this because it simplified the argument, because I could enlist eliminative materialist Jim Stone to support me (at least 1985 eliminative materialist Jim Stone), perhaps against his will, and because I was setting you up for TMT. But I was also surreptitiously trying to get a toe in the doorway to you accepting that you exist, against knee-jerk cries of Cartesianism for example, so I could pry it open and let much more in. Because I think it is very clear that if we grant each of us our existence just in the present moment at least, if we grant in other words that we have the thing we want at this moment in time at least, that the present is the state of affairs we are satisfied with in regard to what we are referring to when we say “I exist”, then we must grant the philosophically contentious but otherwise almost universally accepted idea that we exist—have the thing we want—throughout the entirety of the period of time of the lifespan of the human body that is each of us. Stone was wrong that we only exist at this moment. The thing we want obtains more than just at this moment.

First of all, every one of us has had this thing we want, existence, every moment of their life from the dawn of their consciousness (whenever that was, and whatever that might mean; discussion of this question will come in Part V) up until the present moment. There is nothing lacking for each of us when we reflect on our past, no notion that we wish we had had the thing we have now in the past of our body as well. To our present self, the thing we want obtains now and had obtained in the past. It has obtained all along. This is not in doubt, we do not feel lucky that it has obtained, or feel that even though we exist right now we might not have in the past of our body, it might not have obtained in the past of our body. And this is not something you should be able to make someone doubt by analyzing the connections (or lack thereof) between that person now and the person of the past (as for example is done when examining personal identity). We already have that, already have what we want, in the past period that this body was alive. Arguing it away wouldn’t suddenly make someone wish they had had it, wish they could change the past and make something obtain then that didn’t obtain then. We are satisfied with this state of affairs, with the relationship of the past of our brain and body, to the obtaining of the thing we want, our existence.

More importantly though than affirming this past existence, the past obtaining of the thing we want, we keep finding that the thing we want continues to obtain in every succeeding moment of the life of this body. No matter what the future content of our lives is, and no matter what the connections or lack thereof we find upon reductive analysis between “me” now or my body and brain now and the person or “me” or body and brain in the future, I nonetheless know that what I want is going to obtain as long as this body and brain continues to exist in a normal manner. It is perfectly reasonable to expect this, because it happens every time for every person (or, if you like, human body), under all but the most extreme circumstances at least. It is not even a question. When the time comes we’ll (still) have what we want. We know this. Call it an induction if you want. But it just simply is not a worry for anyone, that their body and brain might continue to live and be conscious in a normal manner, but that they will cease to exist, that the thing they want will disappear. No analysis of the connections between myself now and this future person can change this fact. What I want does/will obtain in that future person.

In short, if we grant our existence—that the thing we want obtains—minimally at this present moment in time, then we have to grant it for the entire life span of the human body we are. The thing we want obtains as long as our body stays alive.

What we actually do worry about is losing this thing we want in total bodily death (or, much less frequently, brain death, or for example coma from which we do not waken before total bodily death). We materialists all feel quite sure that we will lose this thing we want in that inevitable case, and this is the source of much of our anxiety in life. (And even those who believe in souls very often have this fear, though it is inconsistent with their professed belief.)

And so the question to ask is, in a purely material world, with no souls, what can we have after death? We know we cannot keep the content of our life. But we have seen that we care about this much less than we think we do anyway, or should care about it much less than we do. So the real question is: can we keep this other thing we want? Can we keep the personal existence, the “I exist”? This is something we want a lot[38], and I can think of no reasons why we should not want it. If you understand the argument from Part I that there is no logical or necessary connection between your existence and your human body, then you may at least find this a less unreasonable possibility than you did before you started this essay that you might indeed be able to keep this “I exist” after death. And I think there are good reasons beyond this to believe this, reasons that follow from what we should believe about coming into existence, reasons that relate to the central mystery of coming into existence I described in Part I.

In Parts III and IV I argue for these conclusions.

Part III: How To Reject The Gamete-Dependence Claim

  1. A Gamete Sorites: Could Other Gametes Have Produced You?

a. Matter Sorites

Consider, once again, the gametes that produced you. More precisely this time, we would say the gametes that produced your human body. These gametes and this human body are ostensibly what have caused you to exist, but we don’t know why, don’t know what the connection between them and your existence is. So we’ll just revert to the simpler colloquial expression “the gametes that produced you” for now, and we can understand it in the pre-philosophical way that most people do, which includes producing both your human body and “you”, your existence or your “I exist”. These gametes that produced you are, by definition, the A gametes, the same A gametes we’ve been talking about all along.

What we are going to do now is examine the A gametes closely, and specifically the creation of the A gametes. This is a continuation of the examination of gamete identity in Part I. Specifically, we’re going to perform a sorites argument on the A gametes, the gametes that produced you. “Sorites” comes from the Greek word for heap, and refers to a type of argument involving changing one very tiny part of something at a time, such as removing one grain of sand at a time from a heap of sand and asking, at removal of which grain does it cease to be a heap? This is called the “sorites paradox” or “paradox of the heap”. You may wish to look it up to get a better grasp of it—check out “ship of Theseus” while you’re at it—but it is not necessary. I’m going to label it the “gamete sorites”, but I’ll give the argument in such a way that it will be understandable without reference to the meaning of the name.

We’ll start by doing this gamete sorites to just one of the gametes. I’ll choose the sperm, because sperm are much smaller than ova, and come into existence very near the time they usually take part in the creation of a human being, if they do at all, and so this makes the whole thing conceptually more straightforward. Each ovum, in contrast, is created when the female is still a fetus inside her mother, and lives for many years before it takes part in becoming a human being, if it does at all. But this gamete sorites on the sperm applies to the ovum as well.

Assume in this sorites on sperm A that you would not have come into existence but from both sperm A and ovum A. In other words, assume that the DS (“different sperm”) possibility from the Prelude is not true.

            So let’s do the gamete sorites. I ask you to pay close attention to the details of the process that follows, even if it is tedious. Much hinges on this.

            The sperm that produced you, the A sperm, came into being at a particular place in space at a particular time, from particular matter subjected to a particular process and completed in a particular configuration (meaning the actual arrangement of the matter).[39] These are the criteria of gamete identity I examined in Part I.

            I’m going to start with considering just the matter of sperm A, and will assume that all the others of these factors remain exactly the same, including configuration and the process of its formation. Consider all the matter that actually went into producing sperm A. During a particular stretch of time and at a particular location all this matter underwent a particular process, and out came sperm A, which is the sperm that produced you. Here’s the question I want to ask: if one atom of that matter that went into producing sperm A had been different, would this sperm still have produced you? Would you still exist in that situation, had one atom been different in the production of this sperm, and had this sperm then gone and fertilized ovum A, ovum A being exactly the same ovum (numerical identity) that actually did produce you?

            I think most people would naturally just answer “yes” to this question. And my answer is “yes”, on three levels: my quick intuitive answer is “yes” (actually, “yes, of course, don’t be ridiculous”); my answer is still yes after a cursory consideration of the plausibility of the alternative (see below); and my answer is an even more confident “yes” after bringing to bear every bit of analysis I can muster (see section b iii). But I know there will be many people who are ready to answer “no”, whether out of sincere conviction or just an impish delight in being contrarian. Or perhaps they see where this is going and want to block it. I aim to convince you that this “no” answer is wrong, and if I cannot do that, then at least to show you that it is much more difficult to hold to than it might at first seem to be. “No” might seem to be just an uncomplicated and straightforward answer here, hard to strictly speaking argue with even though it seems a little extreme, but actually there is a hidden arbitrariness to the “no” answer that makes it much less straightforward than it might appear at a casual glance.

            But first of all, to move back to just a cursory consideration of plausibility, consider that each sperm is composed of 100 trillion atoms. For scale, 100 trillion seconds is over 3 million years, which would be roughly the amount of time that passed if you lived the 2000 years between the rule of Augustus Caesar/birth of Jesus to the present 1500 times over.[40] Or if you lived an 80-year lifetime 37,500 times over. Imagine how insignificant one second is to your day, let alone a year, let alone 3 million of them. And so one atom of this structure is an exceedingly tiny difference. And remember that in this situation the sperm still has the exact same configuration as sperm A, including the same DNA, and was produced at the same time, place and by the exact same process, and came from your father. All these factors are the same. Add to this the fact that the matter changes in our own bodies all the time, and it seems really difficult on these grounds alone to believe that one atom difference in the creation of sperm A would have caused you to not exist.

I think most people would agree without further argument that they would still have come into existence if one atom had been different in the creation of sperm A. But even if you cannot accept it, let’s consider it provisionally accepted for now, or accepted for the sake of argument, at least to see where it takes us. This should be easy enough if you can at least entertain the idea that you would have still come into existence in this situation. Certainly no one can be said to know for sure; there isn’t even in principle a way in which it could be ascertained whether it is true. As I pointed out in Part I, we first of all can’t rewind the clock to try it, and second, even if we could, there is no question we could ask the resulting person or that the resulting person could ask him or herself and no empirical test we could do to find out if it was “you” or not.

            So, back to the sorites. Strictly speaking, this sperm that is one atom different from sperm A, even though (or “if”, if you prefer) it would still bring you into existence, is not the same sperm as sperm A. As a physical object, it is very slightly different. So, I need to introduce a new notation for the sperm, so we can be perfectly precise about it. The sperm that would have come into existence had one atom been different during the creation of sperm A will now be called sperm A1, the subscript meaning simply “1 atom difference”.

            So now look at sperm A1. In this slightly alternate world, you come into existence from this sperm.[41] Now we ask you in this slightly alternate world, what if the matter that went into the creation of this sperm A1 had been one atom different? Same process, same configuration, same time and location and parentage, just one atom of matter different. This would be sperm A2; it is 2 atoms different from the original sperm A, though only 1 atom different from sperm A1. Would you still have come into existence if this sperm A2 had fertilized ovum A? If we stick with the reasoning so far, then the answer is yes. To the you in this slightly alternate world, going from sperm A1 to A2 is exactly the same as going from sperm A to sperm A1 was to you. And therefore you exist as that person in all three of those situations, just as surely as you exist now, would still exist now if a minute ago you had moved to the left 1cm, and would still exist now if a minute ago you had moved to left 2cm. And so you thereby believe that you, the person existing right now, who came from sperm A in the actual world, would exist as the resulting person if it had been sperm A2 that had been created and fertilized ovum A.

            And so, we can continue this, to A3, and A4, and beyond, until we get to all of the atoms. I’ll notate this last situation as Aa, for “all”. So sperm Aa is a sperm that was created from the same process on the same plan (in the same configuration) and in the same location and at the same time and from the same parentage as sperm A, the sperm that created you, but of entirely different matter than sperm A. And yet, we still think it would be a sperm that came to produce you, if you follow the reasoning from sperm A1 to sperm Aa, where each step, each single atom difference, still is a sperm that would have produced you.

Now, before we move on, let me be really clear about what I am asking you to imagine here, about how we arrived at sperm Aa. There’s several ways this sort of sorites argument could be conducted. We could be imagining taking sperm A already created and then changing out one atom at a time and asking at each point whether it would still be a sperm that produced you. This is similar to what we already did to the A gametes at the very beginning in PD, with the optional stipulation that the atoms of the A gametes would be swapped out before they were taken to the spaceship and brought back to earth (and the same for the B gametes, if they had been chosen). And this is also what already happens in your body every day, and what surely happened a little bit to your actual A gametes in actual reality before they joined. But this is not what I’m asking you to imagine here. What I’m asking here is that, each time I call for one more difference in the atoms that went into the creation of the A sperm, you imagine that a sperm was created from the beginning from those one or more different atoms instead of the way the actual sperm A was created. In other words, at each step, reverse in time in your imagination and have a sperm created out of this slightly different set of matter. The difference between these two ways of conducting this thought experiment is subtle but important. (There is a third way to do the sorites, which will come up in section b ii.)

            Having all that in mind, let me then point out what is powerful about sorites-type arguments (in the spirit of some of Parfit’s thought experiments on personal identity, which I will also come to in section b ii): we are led to see that there can be no non-arbitrary cut-off point for when the change we expect to see actually happens. In this case, the change you might expect to see is that, at some point, the sperm will no longer be one that would bring you into existence. If, for example, I were to ask you cold to just imagine a sperm created out of entirely different matter than sperm A, the sperm that created you, even of the exact same configuration and at the same time and place, then your first thought might be to say that that sperm would produce a different person than you. But, if I then ask you whether, if a sperm had been created of all the same matter as sperm A save for one atom difference, then your first thought might be to say that it would still have produced you. What the sorites argument shows is that these two beliefs are contradictory. If you believe that sperm Aa would not produce you but sperm A1 would, then you have to believe that there is some cut-off point between sperm A1 and sperm Aa where the change in that one atom causes the sperm to go from being one that would have produced you to one that would not have produced you. But it would be unavoidably arbitrary to believe that of one atom and not any of the others. To say that sperm A10 would still bring you into existence but sperm A11 would not would be an oddly arbitrary assertion. To say that sperm A50 trillion would bring you into existence but sperm A50 trillion + 1  would not would also be an oddly arbitrary assertion. Even to say that sperm Aa-1 would bring you into existence but sperm Aa would not is oddly arbitrary.

In fact, the only possibly non-arbitrary point would be to say that sperm A would bring you into existence, but sperm A1 would not. Let’s call this the A1-X view: the belief that if sperm A1 had been created[42], then you would not (X) exist. It seems to not be arbitrary because it is the only time we are moving from something actual, and which actually did bring you into existence, sperm A, to something that is not actual, and which we therefore have no evidence for or against whether it would have brought you into existence, sperm A1. If one wishes to block the sorites, so to speak, this would be one very tempting way to do it. But in fact even the appearance of non-arbitrariness in this case is deceptive, as I said above, and as will be explained in section b iii.

While we’re on the subject though, consider another cursory consideration of the plausibility of the A1-X view. If A1-X were true (if a change of only one atom would have caused you to not come into existence), then that means there were 100 trillion potential other people that would have come into existence between sperm A and sperm Aa had it fertilized ovum A, but did not, just in this scenario alone.  That is a lot of a poor unfortunate non-existent people, and the odds against you coming into existence just increased by an astronomical order of magnitude from what was already an unimaginably large number. Economy alone—really grasping the magnitude of a number such as 100 trillion (1000 times the number of people who have ever existed)—impels me to think that one atom difference in one of my gametes would not have prevented me from coming into existence, even without other convincing arguments.

Another point: you might be wondering what this process is that the matter goes through to produce a sperm (any sperm). There is, of course, a known answer to that. By now, biologists know every detail of how raw matter becomes a gamete. I have a passing familiarity with it, and could probably explain it clearly here if I did a little research. But actually, I think it does not matter for what we’re doing here at this point. When I imagine the process that the matter goes through to become a sperm, I’m basically just imagining all the matter as separate atoms going into one end of a black box, going through a process in the box, and coming out the other end of the box as a sperm. I think this is enough. It seems to me that any possible process would be amenable to the arguments I’m subjecting the process to here—even if it occurs in several discrete stages rather than all at once, as human gamete creation actually does, and even if those stages are quite distant from each other in time space—so there is no need to worry about the specifics. In fact, it seems that the details would make the argument stronger if they affected it at all, so what I present here should be a weaker case than actuality. But for simplicity I’m going to stick with my schematic description; atoms (or molecules if you prefer) go in one side mostly unconnected to each other and come out the other as a gamete.

This is the first step in the gamete sorites. I have three tangential points to make before I return to it and take it to its conclusion.

b. Three Tangential Points


Not all of these three points will be necessary for or interesting to everyone; for some people none of them might be necessary, and you might find them tiresome. Section iii in particular could be quite tedious. Anyone who is not concerned about the points I am arguing in these sections can skip ahead to the rest of the gamete sorites, which begins again in section c.

i. The Incoherence of Being Partly One Person And Partly Another

            There is a hidden premise to this sorites argument, which I should clarify now: being “you” and being “someone else” is not something that admits of degrees. A gamete cannot fade from being one that produces you to one that does not produce you (one that produces someone else), one atom at a time. Either you come into existence from a gamete, or you do not. There is no middle ground, there is no such thing as a gamete or zygote or person being, say, half you and half someone else.

This might be controversial, and it is certainly worthy of critical examination, which I invite. But I assert this because I frankly cannot think of any account that could be given for what it would mean for a gamete, say a gamete somewhere between sperm A and sperm Aa, to be half me and half someone else (or one that would bring half me into existence and half someone else into existence). Remember we are not talking about content here; this sperm Aa has qualitatively identical content to sperm A. We are talking just about pure existence, isolated from content. And what would it mean to you to only half exist, or 5% exist, in/as a human being that was qualitatively identical to you now? And the other half or 95% would have to be someone else. What would it mean to only half be a person in a counterfactual universe; a person, it must be said, who would think of him or herself as a simple, single whole person, just as you do yourself right now? How would this counterfactual person be related to the whole person you are now in this universe? What would the half you in this counterfactual universe be half of from the whole you in the present universe? How would his or her “I exist” relate to yours? Think about what it is that is obtaining right now at this moment, which you take to be 100% of the thing you want and is wholly satisfactory itself, is 100% of what you want to obtain, and then try to imagine it only half obtaining, or some other percent. Can you imagine anything at all then? Further, try next to imagine the thing you want that is obtaining at this moment only half obtaining, and also being wedded into a single whole with the thing a different counterfactual person wants that is only half obtaining for him or her. What would this be?

I mean really take some time to try to imagine this. Don’t just read the questions and sentences and quickly move on. You should really consider this.

It is easy to imagine this for specific content, a specific DNA sequence for example, or for specific mental content. There is nothing mysterious or difficult about imagining the content in the brain of a person, whether you or someone else, being 99% of what the content of your brain is right now, or 50%, or 1%. Nor is there any conceptual difficulty in imagining this about DNA. But if this is what you are imagining, then you are imagining the wrong thing. We are not talking about content.

Even if you felt your existence fading, as it were, due to a degenerative brain disease such as Alzheimer’s, you would count this as your content fading, but your “I exist” would still be 100%. You would still exist. It would be the yes answer to a yes and no question. If this doesn’t sound right to you, recall your very first memory. Mine was at what I think was age 2. I was in a basement playing with other kids, and I walked over grabbed the toy out of the hand of another kid. The kid protested (cried and/or got angry), and my mother heard the cries and scolded me, and I felt very bad about it. If I think about it really hard right now in fact, I still feel bad about it, because I remember it subjectively, from the inside, what it felt like to take that toy, and what it felt like when I noticed the kid crying after my mother brought it to my attention. I think my first memory was also the first flowering of a very strong internal sense of right and wrong, and shame at hurting others. The point for our purposes is that, when I look back at that memory, though it is extremely fuzzy, I don’t think of it as, that was me when I only existed about 10%. No, I think, I existed then. That was me existing. I had only a very small fraction of the content I have now, and thus my consciousness was very fuzzy and disjointed, and it doesn’t feel to my present self like I was exercising free will, but was just acting animalistically. But I existed. (I have no precise definition of what “fuzzy and disjointed consciousness” means, but I will discuss consciousness a little at the end.) The thing I want obtained back then. If I had had the language to describe it, I would have said “I exist!”. Not, “I only 10% exist”. And I think this is the way everyone thinks and speaks. We think we existed all the way back to our first memories. We always had 100% the thing we wanted. It was never a matter of degree, and it is inconceivable what it would mean to say that it is.

Consider again if I had this faded existence due to a degeneration of the physical body of my brain. Though it is surely not the sort of thing that admits of a precise number, let’s decide to say that the degenerated state has left my mind at 20% of what it was before the degeneration started, when I was healthy. If through surgery—the replacement of the degenerated portion with healthy cells created outside my body—this brain were brought back up to the power and capability it had before the degeneration, I would not think that I still exist only 20%, and this other person now exists 80%. No, I would think that I still exist, and my content (or perhaps potential for it) is once again 100% what it was before. (This raises a lot of other questions I’m going to briefly put off. Parfit would surely call—more or less already has called—this question empty, a point I will get to in section b ii.)

There is no concept of degrees attached to existence. Whether a child or an adult, whether degenerated or healthy, we consider existence itself to be 100% or not all. Similarly to the above, if my currently healthy and “normal” brain were enhanced by some process, made ten times as large and/or ten times as “powerful”, I would not before the process think I am only 10% of a person, or that I only exist 10%,  nor would I in the resulting case think that I am only 10% of this resulting person, sharing with the 90% person who exists (or persons who exist) from the enhancement. No, I would say that I and only I now have 10 times more brain power than I did before, whatever 10 times means.

Or consider this. Think of yourself in the present world, just as you are now. If “partly existing” were the result of this gamete sorites, then it could not be distinguished from what you assume is true now, that you are all you (the way I assume I am all me). And so, if it were the case that, say, a sperm A50 trillion was only half you (or a quarter, if you prefer), then that would necessarily be true in all cases for all people who exist now and ever could exist, that every person, including you, are actually right now partly one person from one alternate universe and partly another from another alternate universe (or possibly the same one), as your A gametes fall on a spectrum between two other possible gametes (many more than that in fact, and possibly an infinite number). One could take this as a fact of life, but it seems to me meaningless, because what everyone means when they say “I exist” is “I exist as one whole person”, and this is the primitive belief about the term “I exist”, at bottom the true referent of its utterance. It also multiplies entities far beyond reason or necessity.

Or consider this. If the idea of a partial or blended existence is coherent, then you should be able to imagine a situation of fading from one existence to another while content remains constant. In other words, one existence fading out to zero while another fades in to “100%”, within a single human being, while the content of that human being remains constant. Imagine it happening to you right now. Over a period of about a minute, say, you fade out of existence, and someone else fades into existence, within your body (the body that starts out this continuum as yours), while nothing about the content of your mind or brain changes. Or at least, nothing more than would be usual over a period of a minute; perhaps you can imagine you are starting at a single object, a white wall or a tree, with constant sensory input for your other senses as well, so that your body is receiving little new information.[43] What is there to imagine in this situation? At 30 seconds in, you would supposedly only half exist, and someone else would half exist together with you, with that same content. At the end of it, you have ceased to exist, just as you imagine you do when you die, while someone else has come into existence. I think there really is nothing to imagine here. The idea of a fading existence, isolated from changes in content, really is incoherent.

(Perhaps you think you can imagine this. For example, your field of view becomes dimmer and dimmer, while another person’s in the same brain becomes brighter and brighter. This would be a simple way to imagine it, since sight plays such a big role in what we think of as our existence and our consciousness. But an even better way to get at the same idea would be: your existence encompasses less and less content of the brain, while another person’s encompasses more and more, while the total content of the brain remains constant. This is much like the zombie problem, in that we’d have to postulate that the human being outwardly remains the same, indistinguishable from a human being in which this wasn’t happening,[44] since what we are trying to make sense of is the idea of a human being living their whole life like this, as person A5 billion or whatever. And in fact this is the answer to why this is the wrong way to imagine it: we aren’t imaging two people existing in the same body, as in a brain bisection or dissociative identity, but two existences blended together and functioning as one. Not oil and water, but coffee and cream.)

And it seems like nobody else can conceive of what a blended existence would be either. If it were conceivable, then it would have, for example, been a ready answer to the DS problem. Rather than wondering whether you would have still existed if a different sperm had fertilized ovum A, you could just say, “well, I would have half existed in that case.” Or, if you prefer, if you want to take it as a percentage of the total matter, then you could say “I would have been .00167% less the same person as I am now.” But almost nobody gives that answer. Almost everyone says, as we have seen, that had a different sperm “won” the race to ovum A (to use the colloquialism), then they would not have existed at all, full stop. And a few people say that they would have existed, full stop, no matter which sperm had fertilized that ovum. (Again, I don’t know who these people are, since Parfit did not provide a citation for this claim.) And I think this is because, without even reflecting on it, none of the people who answer in either of these ways can conceive of what it would mean in that case to only half exist as the resulting person either, and so the option doesn’t even occur to them. (Parfit, remember, said the question may be empty, a point which again I will consider in section b ii.)

This is, incidentally, more evidence that people naturally think of content and their existence as separate, without consideration even of the types of painstaking analysis I’ve done, because, as I said, people have no trouble imagining the resulting person having only half their genes—the half from the ovum only, whether they are imagining it to be themselves or not themselves. (Much more actually, since humans already share 99.9% of our DNA, and those so do human sperm, but this is the way people would naturally think about it.) There is no mystery about this, no philosophical question to it. But they don’t imagine this being the answer to what would have resulted if a different sperm had fused with their ovum. They imagine a further question, the question of whether they exist in that case. And the answer to this is yes or no.

Since I have never heard anyone assert that they would have been only partly another person in any counterfactual situation, or even that they could conceive of what this would mean, what it would feel like, what the phenomenology of it would be, and since, as I said, I myself cannot imagine it, my attempt to argue against this idea is without a clear opponent, and so has not been shaped and polished yet by any back and forth. If there is anyone who does believe this, I would like to hear the reasons for believing it and the description of what it would mean.

And if these arguments against vagueness in existence don’t convince you, I have others to come later. First, vagueness doesn’t make the indexical view any less arbitrary, and second, my ultimate conclusions achieve an internal consistency that removes the motivation for trying to see existence as possibly being vague anyway.

ii. Empty Questions

That I have not heard the above argument before may be because my gamete sorites is the first time the idea has come up. But Parfit’s physical spectrum is a candidate for this, and what he and other people have and have not said about it is instructive. In what he calls the physical spectrum, Parfit asks us to imagine some portion of our brain, one neuron or 1% or 50% or 70% or 99% or all but one neuron, being replaced by a qualitatively identical neuron or brain portion. On the near end of this spectrum, where only one neuron or 1% of our brain were replaced, we think we would still exist. But at the far end, of 99% or all but one neuron, we think this is close enough to 100% of our brain being replaced that it would be the same as dying and another person coming to exist in our place. At some place in the middle portions of the spectrum, whether around 50% or 60% or 70% we are puzzled. Any place we choose to count as the place where we cease to exist would be arbitrary, just as in the gamete sorites.[45]

Parfit calls the question of whether the resulting person would be you somewhere in the middle of the physical spectrum empty. Recall again that he said that it may be an empty question whether in DS the resulting person would be you.

Let me take a moment to remind you of what an empty question is. In the discussion of DS in the Prelude, I quoted Parfit: an empty question is one in which “different answers to our question are merely different descriptions” of a single fact or outcome. Also, “without answering [an] empty question, we can know everything there is to know” (214). As an example, I told you the story about your father making you a Cherished Pencil while dancing to “Raindrops” by Basement Jaxx, and you imagining what would have happened if he’d been dancing to salsa music instead. The wood would have been cut slightly differently, and the resulting pencil would have been made of a slightly different portion of wood.

You could then reflect, well, then this pencil would have had a few different atoms. You might say this because what matters to you about this pencil being this pencil is that your father made it especially for you and gave it to you at a certain time and place. Alternately, you could choose to think that if that had been the case—if your father had been dancing to salsa instead of Basement Jaxx when he cut your pencil—then you would have a different pencil in your hand right now, even though the pencil would mean exactly the same to you. You would be cherishing a different pencil. It would be a different pencil that had the exact same meaning for you.

The point is, nothing turns on whether you choose to describe this situation in one way or another. You description of it as the same pencil or as a different pencil is not a description of a fact about the situation, a further fact to the material constitution of the pencil, but just the way you want to think about it. So to ask “If my father had been listening to salsa music when he made this pencil and had cut the wood slightly differently, would it have been the same pencil I’m holding right now?” is an empty question. Without providing an answer to this question, we can know everything there is to know. The physical constitution of the pencil is everything there is to know about the pencil. There is no additional fact to know about whether the pencil is the same pencil you have now, or whether the pencil you have now would still exist in the counterfactual situation of the salsa music.

This is what Parfit thinks about the middle (or late middle, since the middle would be just like brain bisection) of the physical spectrum for your brain. It is an empty question whether the resulting person would be you. (And thus he would likely call the question empty in my imagined scenario above about the content of my brain being reduced to 20% of what it is now, and then augmented with matter from another source.) And I think Parfit would answer the same way about the gamete sorites. I think Parfit would call it an empty question whether the resulting person somewhere in the middle of the gamete sorites would be you, so similar is the question (and its consequences) to the physical spectrum.[46]

It is interesting first of all that neither Parfit nor anyone who responded to him (as far as I know) thought to claim that the result of the physical spectrum (or the related combined spectrum) would be partially existing. That, if 30% of your brain were replaced with identical neurons, then you would exist 70% as the resulting person, for example. This gives more credence to my belief that such a thing is incomprehensible. People don’t think of it as an option for something to believe because they can’t conceive of what it would mean. Partial existence is a meaningless expression. The adjective just doesn’t apply to the referent of the subject.

But perhaps I should instead accept that “empty question” is the correct way to describe my gamete sorites. Rather than giving “partial existence” as the only alternative to answering the question as “yes”, and then declaring that “partial existence” is incomprehensible and that “yes” is therefore the correct answer by default, I should settle on calling the question empty. Perhaps even calling the idea of partial existence meaningless is what leads us to calling the question itself meaningless, which is the same as calling it empty. Perhaps this is a route to seeing that the question is empty (though this is not the route Parfit used.)

Perhaps, but I think I have a better way, for intermediate cases of gamete identity at least; the intermediate cases of the physical spectrum are a harder question, though I have an idea to offer for them as well. These will come out in my conclusions.

One of the problems I have, and a motivation for finding a better answer, is that I still have no idea what it means to call a question about my own existence empty. It is just as incomprehensible as saying I only partially exist. Though I might accept it provisionally while reading Parfit, so compelling is his argument for it, I nonetheless find at later moments that on reflection I can’t make sense of it. And so I wonder if it can be right, if calling a question about my existence “empty” really is taking the true referent of “I exist” as its object of examination.

Consider just as one aspect of this incomprehensibility something I brought up in the previous section, that if partially existing were the true result of the middle portions of the gamete sorites, then it would be the case right now that possibly an infinite number of people partially exist as you right now, the person you are that you take to be 100% yourself, 100% the thing you want. Taking the question instead to be empty, we end up with the same thing: empty questions about existence do not just exist in far-fetched science fiction scenarios that may never come to pass, but are in fact the case right now. It would be an empty question whether one of the people who would have come into existence in a counterfactual situation of the middle of the gamete sorites is you right now. In fact, it would be an empty question whether possibly an infinite number of counterfactual people are you right now in this actual universe, or, to put it differently, it is an empty question whether any of these people exist. I find this a confusing way of looking at things. Unnecessarily cluttered.

As I said, my better view will come out at later. I don’t consider my problems with empty questions that I’ve explained here to be any kind of convincing argument. But I think these issues are worth keeping in mind when comparing the idea of empty questions about existence with my alternate account. So after I complete my explanation of it you can help me decide if it is better than calling intermediate cases empty.

iii. The Hidden Arbitrariness of The Indexical/Butlerian View (A1-X)

Before I do get back to that explanation, I still have one more tangential point to get out of the way: why the A1-X view is arbitrary and by extension why what I’ve called the Butlerian view does not dissolve the questions about existence I’ve been raising in this essay. In other words, why existence cannot simply be an indexical fact on belief in the gamete-dependence claim. As I said, this argument in particular may seem quite tedious to many people, especially if you are not tempted by either the A1-X view or the Butlerian view. For some people, this section can be skipped, and you can take up the sorites argument once again in section c.

Let me restate the Butlerian view first. The original statement of it is that everything just is what it is and not another thing. Applying it to people it would be that every organism (or conscious physical being) is the organism it is and not another. There is no mystery to why you exist because every conscious organism has to be someone. Saying that you exist because your gametes existed or your human body exists is just a correct statement of a brute fact.

If you want to believe this, then I think there are certain other beliefs that this entails. This Butlerian view of personal existence would certainly seem to invite belief in the A1-X view for example, and possibly might outright require it. The A1-X view recall is the belief that you would not exist had one atom been different in the creation of one of your gametes. And so, since sperm A1 is not sperm A, then person A1 is not person A. And so if you are person A, then you are not person A1. If person A1 comes into existence, then you do not exist. So I will take these two beliefs up together, first showing how the A1-X view is more difficult to hold than it first appears to be, because it is much more arbitrary than it appears, and then I will show how the argument that leads us to this conclusion is detrimental to maintaining the belief that the Butlerian view applies to persons (an elaboration on the argument I started at the end of Part I.)

Here’s something we all know to be true about as well as we can know anything: if in the past week or past month you had eaten nothing but steak, broccoli and baguettes for the entire time instead of what you actually did eat, you would still exist right now, all other things being as equal as possible. Your different actions wouldn’t mean that right now you wouldn’t exist. You would just be that person. More importantly, if that is indeed what you had eaten, there would be some different atoms making up your body and brain right now than the ones that actually do. And yet, you would still exist right now, having a body made up of different atoms than the ones that make up your body now. That differently constituted body would still cause the thing you want to obtain, would still be the carrier of the thing you want, your existence.

This is the point: right now, it does not matter what the specific atoms are that compose your body. Any number of changes to the matter in your body, possibly an infinite number, could come to your human body, and you would still exist. Right now, changing out atoms of your body does not affect whether or not you exist, whether or not the thing you want obtains. This is something virtually everyone believes, to the point where it can all but be taken as fact.

Let’s call this fact C-OK, for “change okay”. A more elegant term would probably be something like “matter insensitivity”, but I like the fact that the meaning of C-OK is so immediately apprehensible every time it is used. That “change” is a broader term than “matter” is also useful, because we believe that other changes could come to our bodies besides just the matter without causing us to cease to exist, such as changes to the configuration of our body and brain even if the matter stays the same (new memories, or other changes to the configuration of our brain, and even losses to the physical structure to a limited extent), or changes in location. But for clarity, and because this is where we are in the gamete sorites, I’m just going to focus on matter, and specifically the atoms.

With this fact in hand, virtually indisputable[47], we can then go back in time and find that we believe every bit as strongly that this is true for all the time at least up to sometime before birth; C-OK still obtains as we go back in time through the history of the existence of our human body. All kinds of different changes could have come to our bodies than what actually did when we were 20 years old, or 10, or 5, or 1, or 1 week old. Even the moment after we were born, I think we all agree that whether our mother immediately started breast feeding or the doctors had immediately begun feeding us an infant formula, we would still exist right now and in all the moments between. The atoms in our body would be different, but we would still exist. How about before we were born? Surely yes. Almost everyone believes now that birth is not the moment of creation of anything, but just the movement of an existing human being from one place to another, from inside a womb to outside it. How about just after the fertilization of the ovum A, at the very start of the zygote stage? Surely yes. Our mother could have eaten a whole range of sustaining diets during our entire gestation, and our developing body could have therefore been composed of many different atoms than it actually was, and we think we would still exist right now. And surely this applies right back to the moment of conception, the moment of creation of the zygote, because any point in time between then and any later time (including the present) would be arbitrary.

How about each of the individual gametes A? Could their atoms have been changed out? Surely yes, although a few people might start to get uneasy around now when they are forced to think about it. But how could it not be true? Especially the ovum, it existed for on the order of several decades before it took part in the creation of you. Atoms came and went through that ovum, sometimes being part of it, sometimes not, during that time. Perhaps even from the time of creation to the time of fertilization all of the atoms were changed out several times over. (I don’t know the biology, and it’s too weird a question for Google to answer.) Surely this situation is the same as it is for your body right now; surely C-OK obtained from the time of creation of the ovum up to the present. And so too for the sperm then.

If you feel inclined to doubt this about the gametes, even a little, I’ll come back to you later. For what I say about the moment or period of creation of the gametes can be applied to any other time as well. To get the examination underway, we have to choose one point in time or one event to look at, and since gamete creation already sees the widest agreement (and is, I think, the least arbitrary) as a point when such changes will not make a difference to the existence of the person, we’ll look at it, and you can take it just for the sake of argument if we can find no agreement on any other reasons.

So we look at the point of creation of the gametes. Let’s switch back over to sperm A. If you believe the A1-X view, then you believe that if even one atom had been different in the creation of sperm A, then you would not exist. The person who came from sperm A1 would not be you.

So now consider an atom Y. Atom Y went into the creation of sperm A right from the beginning, and it remained in sperm A until it fertilized ovum A, and then became part of zygote A and then embryo A and then fetus A and then newborn baby A, and (let’s say) is now still part of your body. Now consider atom Z, which is of the same substance as atom Y (carbon or hydrogen or sodium or iron or whatever; we can change it to molecules Y and Z if this makes more sense to you). If atom Z were to replace atom Y in your body right now, no problem, you would still exist. If atom Z were to have replaced atom Y in your body when you were a newborn, no problem, you would still exist right now. If it had replaced atom Y in the zygote stage, no problem, you would still exist right now. If it had replaced atom Y in sperm A prior to fertilization, no problem, you would still exist right now. Therefore, if it had replaced atom Y immediately after sperm A was created, you have to think no problem, you would still exist right now. But if you hold the A1-X view, you think that if atom Z had replaced atom Y in the process immediately before sperm A was created, then this is a problem, because you wouldn’t exist right now.

After the creation of sperm A, either all of the atoms in sperm A could have remained part of sperm A and none others, or like atoms from anywhere in the universe could have replaced some or all of the ones in sperm A, in any combination imaginable, and it would have remained sperm A, the sperm to bring you into existence. This is the same as is the case for your body right now. This is C-OK. Before the creation of the gametes, the A1-X view, only the atoms that did could have gone into the creation of sperm A in order for you to come into existence; not a single atom could have replaced the atoms that went into its creation. I’ll call this fact C-NOTOK, for change not ok.

This invites the question: what is happening during that period of creation that is so special, so pivotal, as to make your existence go from being totally sensitive to the matter involved to not sensitive to it at all? What sort of event in the creation of a sperm could be the sort of thing that would cause this fact to change over from C-NOTOK to C-OK? If you remember the discussions of gamete identity the answer should be obvious, so it shouldn’t be spoiling any drama just tell you: there is nothing that could possibly or even reasonably perform this function. No event, no physical structure, nothing.

But let’s look at it closely anyway, to really heighten the absurdity. Let’s assume something that in most cases likely isn’t true: that there is at least an unambiguous moment we can point to and call it important, or at least question whether it might be important. We’ll take this to be a moment in time when atom Y “locks in” to the structure of sperm A, or more accurately, the structure in the process of becoming sperm A. This “locking-in time” I’ll call time L. Again, we’ll look at this very simply and schematically, without concerning ourselves with the actual details. The actual details are surely much more vague than what I’m going to present, and so would make things even harder for the A1-X view, so if we can show it to be absurd in the simplest and most generous telling, then this will be detrimental for all other versions as well.

So atom Y makes its way to the site of creation of sperm A. Really try to imagine it, flowing through your father’s bloodstream, disembarking at the appropriate location,[48] and just hanging around the site of creation of sperm. At some point in time it goes from being a part of something else—anything else—in your father’s body, and becomes a part of sperm A in its process of creation. It is locked into the sperm-A-in-process of creation. If, at some point in time after this locking in time L, atom Z comes swooping in and replaces atom Y in that structure, and atom Y goes off and does something else unrelated to sperm A, then we all believe that sperm A will still be sperm A, will still bring you into existence if it fertilized ovum A. “At some point in time after” is at least something everyone must agree on, because it is true of your body right now, which is indeed a point in time after time L. But let’s make it more precise (if not completely so): a point in time just after the locking in. Could be mere nanoseconds, or less. Some very short period of time after the locking in, whatever you wish it to be. (We could choose a point in time just after the completion of creation of the sperm if you find this more satisfying; it makes no difference, but I’ll mention this in a moment.)

So atom Y locks into the structure of sperm A in progress, and then atom Z swoops in and replaces it mere nanoseconds later; atom Z remains in the sperm in progress and in the completed sperm, while atom Y goes off an does something else unrelated. And you come into existence when sperm A fertilizes ovum A.

Now consider the alternative situation: atom Z instead swoops in and replaces atom Y in the process mere nanoseconds before this locking in time, and atom Z is locked into place instead, while atom Y goes off somewhere else, never being part of your body. If the resulting sperm fertilizes ovum A, you will not come into existence. This will be sperm A1, and thus person A1, which will not be you, will not cause the thing you want to obtain. Unlike now, when atom Z replacing atom Y would make no different to you existing, to the thing you want obtaining.

When I think of this situation, I imagine a diagram like this one:

A1X P.png

The line marked “Actual Events” represents exactly what has happened in the past, up to the present P, in all the events relevant to your existence. Both “events” and “relevant to your existence” may or may not be precisely definable, but we have a rough idea of what they are, as a great many events across the world and probably everything in another galaxy would not or did not affect whether you came into existence or have remained in existence (taking into account that events in another galaxy would have had to take place many years in the past to causally impinge on events on earth), while it is also clear what kind of events certainly would have. “L” is time point L, the locking in of atom Y. Before time point L the line of actual events represents the location in the universe of all of the atoms that went into the creation of sperm A, and if we go back far enough the matter that went into the creation of the gametes that created your parents, and the matter representing their existence and location, etc. It need not be precisely defined, but that is the general idea. After time point L, the line of actual events represents the course through the universe of the structures of sperm A, zygote A, then person A (you), no matter what matter makes up those structures, because that is what is relevant to your existence then; not the specific matter, but the structures. The dashed line represents what I call a “fence” around actual events. Inside that fence is C-OK; variations on actual events that would still have resulted in you coming into existence, or would have kept you in existence if you already were. Outside that fence is C-NOTOK; variations on actual events that would have resulted in you not coming into existence, or would have caused you to cease to exist if you already did exist (such as death).

You’ll notice that the amount of allowable variation in events before time point L is much less than that after time point L. I’ve made the diagram like this to reflect actual beliefs: recall that Dawkins said that “the thread of historical events by which our existence hangs is wincingly tenuous” and Nagel said “there was very little chance of my being born given the situation that obtained an hour before I was conceived, let alone a million years before.” And Dawkins says earlier in this section “you…must regard a particular instant, nine months before your birth, as the most decisive event in your personal fortunes. It is the moment when your consciousness suddenly becomes trillions of times more foreseeable than it was a split second before.” And then: “the instant at which a particular spermatozoon penetrated a particular egg was, in your private hindsight, a moment of dizzying singularity. It was then that the odds against your becoming a person dropped from astronomical to single figures.” Dawkins was talking about conception, as people usually do when talking about odds, but anyone who holds this belief must necessarily believe that the same considerations apply to the creation of the gametes to some extent or another.

 Both Dawkins’ and Nagel’s statements see wide agreement among people in general. Perhaps, upon reflection, a case could be made that it isn’t actually so that the range of possible events before the creation of gametes is much narrower than that after, but I won’t purse that further. The important thing is that at time point L, no variation is allowable. All the matter that went into the creation of sperm A, and your father as a whole human, whatever matter aside from that of sperm A he contained, had to be in the state they were at that point in time and at that location, however it got there, in order for the creation of sperm A to be the creation of sperm A. Perhaps your father could have been somewhere else at that time than he actually was and he still would have created sperm A? No matter. The point is just that there were a huge number relevant facts that could not have been different at that point in time, and very few that could have.

After time point L, or some point in time after you feel it firmly established that you exist (zygote, fetus, baby, etc.), the size of the space inside that fence of allowable variations to actual events without affecting your existence quickly becomes much larger. At this point in time, most things in the world don’t affect whether you exist, and most things that happen directly to you even don’t affect whether you exist. In our normal way of thinking about it, there are many more stretches of time in possible worlds in which you exist after the time you come into existence, than there are stretches of time in possible worlds that would bring you into existence. It is an interesting question whether this actually holds in a rigorous assessment of modality, but at least it is the way we tend to think of it (and what Dawkins unambiguously asserts, in reflection of the way we all think of it).

And now, when I imagine the situation I described about atom Y and atom Z, I imagine this diagram:

A1X ZY P.png

            Here we see atom Z swooping in and knocking out atom Y at two different points in time. In one case, it knocks it out just before time point L, and atom Z goes on and becomes part of the sperm being created instead of atom Y. This results in sperm A1, and you not coming into existence. In the other case, atom Z knocks out atom Y just after time point L. In this case, sperm A remains sperm A, and as long as it goes through and fertilizes ovum A,[49] then you come into existence.

This means, among other thing, that sperm A and sperm A1 could be essentially identical in structure at all points in time subsequent to a moment after time L, containing all the same atoms in the same configuration. But we call them different objects simply because atom Z replaced atom Y before or after this point in time. If atom Z had replaced atom Y a second or day or week after time L, it would still be sperm A. But just before time L it is sperm A1.

So here’s the crux of the matter: if you want to hold to the A1-X view, then everything I’ve just described is a belief you must own. Yet, the only reason I can imagine to hold the A1-X view is to avoid the arbitrariness of thinking that some single atom move between sperm A1 to sperm Aa would have caused you to not exist. And so, to this I must ask, how much less arbitrary is what I’ve just described than that move? I believe it is barely any less arbitrary, if at all. Why should we think that this point in time L is so special? As with so many other things we discover when we examine gametes and our own existence closely, it would seem to be imputing something really magical to a very simple physical process or structure.

And so, better to just believe that the atoms that went into the creation of sperm A could have been different without affecting whether or not you would have come into existence, just as we believe that any atoms could have replaced the atoms that went into the creation of sperm A after its creation.

And remember too that this is just the simplest way of describing it, assuming that there is a clear locking-in point for atoms. In reality, with the actual complex details of gamete creation, it seems that it would get much worse for the A1-X view. Many parts of organic structures are quite fluid, and so it’s not necessarily clear what a locking-in would be there. And the process itself in many or most cases would not admit of a clear locking in time. The atoms and molecules are there in the area of the creation of the gamete, performing different functions at different times, being moved about within the gamete, exchanged between separate structures within the gamete, and most important, exchanged back and forth between the gamete and the surrounding environment, in some cases multiple times. The fact that the creation of a gamete is not so simple or clear-cut as I’ve made it out to be only adds to this vagueness, and thereby adds to the arbitrariness of believing A1-X.

Further, it is clear that you cannot escape this by pushing the changeover from C-NOTOK to C-OK to an earlier or later time. Perhaps you would prefer the moment of “completion of sperm A”. But this is just time point L going by a different name. It has the exact same consequences as time point L.

And the moment of conception is just as arbitrary or moreso, to say nothing of the additional complications. If you believe that only the atoms that composed sperm A and ovum A could have been the ones composing them at the moment of conception (and therefore only the initial atoms in zygote A could have been the ones composing it), what do you really believe? Do you believe that before that time sperm A and ovum A could have been composed of any atoms, as long as at that exact point in time the correct atoms composed them? Or do you believe that all of the atoms from the beginning and the changes to the atoms over time had to have been the same from the time of creation of the gametes to the time of conception? Any such beliefs we find down these trails only seem to be more and more untenable.

And this arbitrariness extends to all factors in our life that we believe do not affect whether we exist, such as the location we are in, or to an extent the configuration of the matter of our body. These factors can vary both in the creation of a gamete, and in the gamete after it exists. You could exist right now on a Polynesian island. Could you exist right now if your parents had been on that Polynesian island for a month already when you were conceived?

Now to turn to the Butlerian/indexical view. The view that everything just is what it is and not another thing is easy to apply unambiguously to objects. The pencil your father made while dancing to Basement Jaxx just is what it is and not another thing. The pencil your father made in the alternate universe while dancing to salsa, with a few different atoms than the Basement Jaxx pencil, also just is what it is and not another thing. This is like sperm A and sperm A1 (or perhaps sperm A12 or sperm A946), considered just as objects. And if, after the creation of the Basement Jaxx pencil, somehow, those few atoms that were different in the salsa pencil became part of the Basement Jaxx pencil, so that the Basement Jaxx pencil was then indistinguishable as far as constitution of matter from the salsa pencil? Would the Basement Jaxx pencil then be the salsa pencil? There is obviously no question here. If the Basement Jaxx pencil undergoes any sort of transformation, it just becomes that thing. It just is what it is and not another thing at that moment. This too is like the case of sperm A, where this time atom Z replaces atom Y after sperm A is created. At that point in time, sperm A just is what it is and not another thing. Very simple, when we are considering sperm just as objects.

But this is exactly the trouble with applying the Butlerian/indexical view to your existence.  The fact is, you have been or (it is generally agreed) could have been or could be right now many different things already. You were a 10-year old child, even though the human-body object of that 10-year old child is a completely different physical object than the human-body object you are now. And your life could have gone differently; you could have been many different human-body objects. You could be the step-child of pirates living self-sufficiently on a Polynesian island right now. Now, it is true to say that the body of that 10-year old child just was what it was and not another thing, that your body right now just is what it is and not another thing, and that the body of that counterfactual person on the Polynesian island just is what it is and not another thing (or would have been what it would have been and not another thing), but they are also all you. Each one of them is or was or would be you. Or, to use the language from Part II, each one of them was the carrier of the thing you want. Or bought the thing you want into existence. And there are billions of other bodies that are not and would not have been you, on the gamete-dependence claim. And so on the gamete-dependence claim the Butlerian view breaks down when it applies to you, to your “I exist”. It is not enough just to say you are who (what) you are and not another thing, because you, what you mean when you say “I”, have been and could be many different things. There are many different objects your “I exist” has and could be. There is, in other words, allowable variation in what objects in the universe can be you. But for anything that is just an object, such as a pencil, there is no such allowable variation. This pencil A right now at time t just is pencil A right now at time t, and pencil A at time t + 1 just will be pencil A at time t + 1, and whatever identity relations we want to decide obtain between these two will be just whatever we decide to call them, for whatever purposes matter to us. But for human bodies, it is not a matter of just what we decide to say, of just deciding whether or not to call this or that possible human body you or not. Each person knows there is a fact of the matter, a real difference between a possible human body—past, future, or alternate reality—being yourself or not. That is, if you believe the gamete-dependence claim.

So there must be a sort of conceptual fence around all objects that were, are, or would have been you, and inside that fence all these various objects—you at age 10, you now, you in a counterfactual history, such as in France or on a Polynesian island—are you, while outside that fence are all the objects that were not, are not, and would not have been you (had they come to be). Further, while it may seem straightforward enough to draw that fence for yourself now, when we get down to gametes (or origins), the drawing of that fence becomes problematic. How big is the “opening” to that fence? One atom wide? In other words, how much variation is allowable to the origin of the object that that fence of things that could be you is surrounding?

In short, Butler’s simplifying and problem-dissolving dictum cannot apply to things whose existence allows for physical variation. (And perhaps the “I exist” of conscious beings is the only such thing?) Your existence, the obtaining of the thing you want, is a constant fact throughout many changes in physical structure. The Butlerian view for personal existence gives way to the fence; everything is what it is and not another thing gives way to many things are and would have been you, and many others would not have been, and not only do we not know where the fence between the two is, we haven’t any notion of what sort of criteria would suffice for placing it.

There is another point here. Vagueness or empty questions about who exists (sections b i and b ii) does not solve this, does not make the Butlerian or indexical view make any more sense. It just makes the fence fuzzy rather than precise. There is still a change from a group of things that would be you to a group of things that would not be you, for no reason at all. The Butlerian/indexical view only makes sense for entities that can only have one physical manifestation. You personal existence is not such an entity.

This is all a consequence of the gamete-dependence claim, which, as I’ve shown, necessarily involves the additional belief in a personal existence factor different from and isolated from content. This is actually what people who make the gamete-dependence claim believe, whether they admit to it or not. The gamete-dependence claim depends on it, unless you are talking about the trivial meaning of “a human-body object exists” that I brought up in DS. But that is something I think almost no one actually believes.

And so, to return to where we are in the gamete sorites, it’s only if sperm A all the way through to sperm Aa would all be you does the Butlerian/indexical view make sense. Perhaps this will get clearer as we get further along.

(And even this is not the end of the argument about the Butlerian/indexical view. There is more to come in Part IV in the section rehearsing the arguments against the gamete-dependence claim.)

c. A Spatial Sorites And Compossibility

            There’s two ways I know of to block a sorites: either claim vagueness in the concept at hand (in this case, personal existence) or deny the first move (in this case, going from sperm A to sperm A1 for example). I think I’ve satisfactorily addressed both. So in my estimation this sorites has been blocked from being blocked, and we can return to the main thread of the argument.

We have sperm Aa, which is a sperm qualitatively identical to sperm A, the sperm that produced you, and was created in the same location at the same time as sperm A, but which was made of entirely different matter. Through the gametes sorites, changing out one atom at a time, we’ve decided that sperm Aa would have caused you to come into existence anyway (had it joined with ovum A), even though it is composed of different matter.

And now that we have this sperm Aa, all the matter that actually went into the production of sperm A is free, available to be used for something. And in fact it could be used to produce another sperm. If all that matter were used to create a sperm on the same plan and from the same process as sperm A, would it be sperm A? We might wish to require that it be produced at the same time and location as sperm A. But as things stand at this point in the sorites, the production of sperm Aa still occupies the point in space and time where sperm A was created in the actual world. So let’s move the production of sperm Aa out of the way, and to make the argument as convincing as possible, let’s do so using the same sort of sorites argument that we just used on the atoms, rather than just giving it a single blunt shove, even though I think most people would find a blunt shove just as plausible.

            If sperm Aa had been created one tiny increment to the side, perhaps a Planck length, would this tiny change in location of production have caused it to become a sperm that would not have produced you, or would it still have produced you in that case? I think we should be inclined to think that it would have, for all the reasons we’ve covered in regard to the atoms, but mostly just for the reason that we would probably think that anyway in the absence of philosophizing. This is, after all, the way we treat inanimate objects. Whether I build this Ikea chest of drawers in my living room or my kitchen, we have no trouble saying it is the same chest of drawers. Whether your father cuts the wood for your cherished pencil here or over there, since it is in principle possible for him to cut the exact same portion of wood in either place, we have no problem saying that it would be the same pencil. Probably even whether the builders of the Empire State Building built it on that block or another, we would still call it the same building if it had been made of the exact same plan and with the exact same materials. And so too, I think, for location of creation of a gamete.

And so, if you believe that had sperm A been created one Planck length away from where it actually was created, then you would still have come into existence from that sperm, then by extension you must believe that if sperm Aa, which from the matter sorites you believe would have produced you, had been created one Planck length away from where it actually was created, then you would still have come into existence from that sperm. This sperm we’ll call sperm Aa,1, where the “a” subscript still means “all atoms different” and the “1” subscript now means “one unit of space over”, whatever that might mean. So from here, we can go to sperm Aa,2, sperm Aa,3, sperm Aa,6008264, etc., until we get to sperm Aa,t, where “t” means “totally different location”. And this sperm Aa,t, we now must conclude, would still be a sperm that produced you were it to fertilize ovum A. It would be absurd to postulate an arbitrary cut-off point between the location of creation of sperm Aa and the location of creation of sperm Aa,t where a change of one Planck length of distance (or whatever) in location in creation would have caused the difference between it being a sperm that created you and one that did not, whereas no other change of location in the entire process did.

            What is this location denoted by the “t” subscript? To do this thought experiment in the tiniest steps and make it most plausible, it should be far enough away that we can conceive of it being causally isolated from the original location of creation of sperm A (and sperm Aa). This stipulation is not necessary, but it will be helpful to keep things simple. Fortunately, the actual facts provided by reality make this easy enough to do, obviating the need for an argument that merely being conceivable in principle would be sufficient (which I was prepared to provide). In humans, sperm are created in seminiferous tubules, one of which is 50-60cm long. A sperm can be created continuously anywhere along the length of one of these tubules. I should think that a separation of even 1 cm between the location of creation of sperm A and that of sperm Aa,t would be more than sufficient to believe that the two are causally isolated from each other during the stretch of time in which they are created (recall that, after they are created, our current belief is that they could interact all they want without changing the fact of “who” would come into existence if they fertilized ovum A). But you can separate them by up to 60cm if you like. The total length of all the seminiferous tubules is 300m, but since these are not continuous, it would take more work to make a convincing argument of the plausibility of a sorites (though I think such an argument would be successful), so we’ll stick with the 60cm for the time being.

            With this process completed, we can get down to the question I want to ask. Sperm Aa,t was created of different matter in a causally isolated location from the location of creation of sperm A, and through a step-by step process of changing one tiny detail at a time about its origins, we have been led to believe that sperm Aa,t would take part in producing you if it fertilized ovum A, just as every possible sperm between sperm Aa,t and sperm A would have. But in this very same universe in which sperm Aa,t exists, all of the matter from which sperm A was created in this actual universe we are living in now is free. There is no particular specification of what that matter needs to be doing or be involved in in the universe in which sperm Aa,t exists. It could be on the moon, or somewhere else in your father’s body. Or it could be put into the creation of a separate, numerically different sperm from sperm Aa,t, without changing a single thing about sperm Aa,t. And in fact, of course, it could be put into the creation of a sperm at the same location and at the same time and of the same plan and from the same process as sperm A; in other words, it could be used to create sperm A, in the same universe in which sperm Aa,t was created; in other words, sperm A and sperm Aa,t could co-exist. And this results in a seeming contradiction: two rival claimants to being the sperm that would produce you.[50]

            There is still, of course, only one ovum A. But it is perfectly clear that all of this argumentation also applies to the creation of ovum A, all those many years before these events, back when your mother was an embryo. Thus, we could also have an ovum A and an ovum Aa,t in the same universe as each other and the same universe as the sperm A and sperm Aa,t. And so, setting aside the idea of cross fertilization here (for example, sperm Aa,t fertilizing ovum A), which produces an intriguing question on our original beliefs in the gamete-dependence claim but which we will soon see to be irrelevant, we have a possible situation in which sperm A fertilizes ovum A, which we feel certain would produce you because that’s what happened in reality, and sperm Aa,t fertilizes ovum Aa,t, which we additionally believe strongly would produce you, because it is implausible that one tiny change in matter or location would cause a gamete to switch from being one that would produce you to one that would produce someone else and not you, and even if that were the case, which tiny change would make that difference would be arbitrary anyway. So we have two candidates for who you would be in this single universe: person A, or person Aa,t.

            This is a problem. You cannot be both of them. The term for this situation, when two things can exist at the same time in the same universe, is compossibility. I mentioned this term at the end of Part I. Gametes A and gametes Aa,t are compossible with each other, and therefore human being A and human being Aa,t are compossible with each other. And so it is a problem that we think they should both be you. I’ll call this the problem of compossibility.

This has led most writers who consider this problem of compossibility to reject that anything like sperm Aa,t would or could be you.[51] But I believe we already know how to answer this problem, using concepts we have had in our possession for many decades already. We deal with this in the same way we deal with the split-brain problem.

d. Split-Brains


The split-brain problem is very well known in philosophy, so I don’t want to spend a great amount of time explaining it. But much hinges on it here—from this explanation follows my revised view of existence and death—and there are many people I would like to communicate with who do not know of it, so I do want to explain enough to get the gist.

            The split-brain problem rests on one fact and one intuition. The fact is that if one of the two hemispheres of a person’s brain ceases functioning, a human being can continue living. And, though there may be personality change, I think by any standard we would have to say the person continues to exist, the thing they want continues to obtain. This is true both of the way we think of them from the outside, and the way they think of themselves from the inside.

So if the left hemisphere dies, they continue living, and have a conscious existence, though it may be reduced in content and changed in aptitudes etc, based only on the functioning of the right hemisphere. If instead the right hemisphere dies, they continue living, and have a conscious existence, though it again may be reduced in content and changed in aptitudes etc., based only on the functioning of the left hemisphere. In other words, if either hemisphere dies, then the thing we want (aside from content) nonetheless continues to obtain.

That is the fact. The intuition is that, if your whole brain is transplanted into a new body (we can assume the body is qualitatively identical to yours, for the sake of clarity), then you will exist in that new body; i.e., “you” will “move” to that new body. This is something I think most people believe. But it must remain an intuition, because we cannot, at current levels of technology and technique, perform such a procedure. But, when thinking about themselves, most people believe that “they” would “travel” to the new body with their brain. They would not cease to exist, in the same way they imagine themselves ceasing to exist when they die.

So putting the fact and intuition together, we should believe all of the following:

(Case 1) If one hemisphere of your brain dies, the right lets say, then you will continue to live and have a conscious existence based just on the functioning of the left hemisphere. If this left hemisphere is then transplanted into a new body (a second body) identical to your original body, you will continue to exist from that left hemisphere in that new body, just as if your whole brain had been transplanted into a new body.

But, what if:

(Case 2) Your whole brain is functioning, and it is removed from your body, but before it is transplanted into the new body, the two hemispheres are split from each other, and the right hemisphere is destroyed? The result is the same as in (Case 1): just your left hemisphere is in a new body. It should not matter whether the right hemisphere died while still attached to your left hemisphere in your old body, or after it was detached outside your body. You should therefore believe as you did in (Case 1), that you will exist in that new body, just off the functioning of your left hemisphere.

So now, what if:

(Case 3) Your whole brain is functioning, and it is removed from your body, and the two hemispheres are split from each other (the same as the previous case so far), but instead of the right hemisphere being destroyed, it is transplanted into another (a third) body identical to your original body? From the point of view of your left hemisphere, what happens to the right hemisphere after splitting should not matter. Once the two are separated, to Lefty (which is the person who is the left hemisphere in the new body) the fate of the right hemisphere is an extrinsic fact. So, if you become Lefty in (Case 2), then you should also become Lefty in (Case 3).

            But here we have the problem, because this exact same story could be told from the perspective of Righty, and we would conclude that you should become Righty in (Case 3). There are competing claims for who you will become in (Case 3). Lefty and Righty are compossible.

            So what actually happens? You should think about this in your own first person case. Do you wake up at all after the two hemisphere transplant? And if you do, which person are you? There are differing opinions on this, and some very detailed reasoning given in support of the opinions. But I think the answer is quite simple. First, I do wake up. I do not cease to exist. The thing I want continues to obtain. If just Lefty is transplanted, then I wake up as Lefty. If just Righty is transplanted, then I wake up as Righty. But if neither hemisphere is destroyed, this is clearly not worse for my existence than if one or the other is destroyed. If both are transplanted, this clearly is not worse than if just one is. I do not cease to exist when both are transplanted if I did not cease to exist when just one or the other was. As Forbes (1980) says, if you believe that you would not be either person if both were transplanted into respectively new bodies but that you would be Righty if only the right hemisphere were transplanted and the left hemisphere destroyed, then, upon waking up as Righty in the latter situation, you could say, “Thank goodness the other half brain was destroyed, otherwise I wouldn’t have existed”. This seems to be a pretty untenable belief. Why not say the same thing if just your left hemisphere ceases functioning while your brain remains inside your own (current) head? “Thank goodness the left hemisphere of my brain just died, otherwise I would have ceased to exist.” Our left hemispheres do not cease to exist every moment of our lives, yet we still feel we continue to exist, still what we want obtains moment to moment. The situation of a transplant should be no different.

            And so, this is what I claim actually happens (and this is the fact on which everything else hinges): I experience waking up as one or the other, but there is no answer to the question beforehand of which I will wake up as, or afterward of why I became that one rather than the other one. There is no logical or metaphysical fact to be discovered; the lack of an answer is deep and fundamental and incontrovertible. There is no answer to the question of which one I will be, there is only an answer to the question of who I am now, both before and after the operation.

            And it is not the case that I am one after the operation more than the other. Both people after the operation will have the same memory of going to sleep as Joe and waking up as the person they are, Righty or Lefty. Righty wakes up from the operation and thinks “I came from that body and moved into this one.” Or, “The result of the transplant was that I became this person.” Lefty thinks the same things: “I came from that body and moved into this one” and “The result of the transplant was that I became this person”. Each thinks they just are Joe, and the fact that there is a rival claimant doesn’t affect that feeling (though it may cause them to reconceptualize it.)

            As I said, this split-brain thought experiment is already well-known within philosophy. For those who know it well and are comfortable with it, I think I’ve made my point as well as I can, and am ready to move on. But I think it will be astonishing to many people who have never encountered it before, and possibly unbelievable. For most such people I think it will require a long time of meditating upon it for it to sink in and to become acceptable (it did for me), and possibly a lot of further study. Really living with it in your own first-person case is the key to understanding why there can be no answer to the question of which person you will become, both in the split-brain problem and in the other cases I will examine shortly, and this is essential to my overall conclusions.

            In my own case, my first exposure to the split-brain problem (in Reasons and Persons) was a shock. I felt compelled to believe it, but felt a lot of resistance because I didn’t want to believe it. I think my nascent philosophizing at the time hinged on the unstated premise that there was something like a soul and that it had an irreducible unity, was indivisible. So it took awhile to accept. It was not an easy thing to fold into my beliefs about myself, and I think it wouldn’t have been even if I hadn’t had any resistance to it. It wasn’t just a desire not to believe; it was trouble just conceptualizing it. It took many years for me to really become comfortable with it, but now I am.

I cannot give you all the time and resources you would need to reach this point, but I’d like to try to give you a little help in wrapping your mind around it, as it were, to see that it is possible, to conceptualize it in your own case, and to understand what I claim would happen if it were done to you.

            One trick I’ve found I’ve been subconsciously using is to try to imagine a splitting of, not my brain per se, but just my consciousness, and it happening while I’m still awake. The splitting of consciousness can be imagined purely conceptually I think, without having to imagine a specific procedure such as brain surgery to produce it. I imagine I am looking straight ahead at any random thing, and seeing that thing as a unified single object. When the splitting begins, it starts with a sort of lateral double vision. I begin to see two instead of one, their outlines overlapping in my field of vision, just in the way we experience normal double vision. And then very quickly after that, the double image resolves into the right-hand side image one and I and the image begin to move to the right. After a certain distance is reached I can turn to my left and see, from the outside, another “me” having the same experience, and moving away in the direction of what was originally our left. It is easiest to imagine a whole qualitatively identical body for both of us, since there is no other available visual representation for seeing another “consciousness” from the outside, let alone recognizing it as your own (or, more accurately, having split from your own). But the body would just be a conceptual stand-in for consciousness itself here.

            And so, as I see this other me, this Lefty, moving to our original left, I can simply know that that person had basically the same experience I just did. He and I were the same person, the same single unified consciousness a moment ago, the same single “I”, and he and I both (which was just I at that moment) experienced the “double-vision” effect, but he experienced it resolving into just the single left image and himself moving to the left. There was only one person, one “I” before the resolving, and after there were two. I could just as easily re-imagine the splitting from the beginning, and imagine instead myself going to the left instead of the right. It would be an equally correct way to imagine it, and equally correct description of what actually happened. It would be equally true. And so there is no answer to the question of whether I, before the split, would become Lefty or Righty. I became both. And there is no answer, even in principle, to the question of why I as Righty after the split became Righty instead of Lefty. There is no mystery about it. The split-brain allows us to see how it is just a primitive fact about how this procedure functions.

            This is just a schematic way to imagine splitting of consciousness. It is not meant to reflect the actual way it would happen, if it is possible at all (surely it is at least physically possible, even if far too complex to perform) and if it is possible for it to happen while a person is awake. For one, it seems likely that there would be no period of “double vision”. Probably you would just experience, in this schematic imagining, moving to the right or left. But I think imagining the double vision is useful stepping stone toward conceptualizing consciousness splitting. (See also Parfit’s “My Physics Exam” 246-247 for a similar example of imagining this.)

            And it is important to remember too that this conceptualization reflects a prejudice we have for vision. I think when most of us think of consciousness we mostly think of being conscious of images. But many people are conscious without having access to images their brain has created from the light information collected by their eyes. Many people, in other words, are blind. There is good reason to believe that the blind construct images through other senses just as sighted people do with light (or at least that they are capable of it, though perhaps not all do). I’m thinking in particular of representations of three-dimensional space the use of through sound, as bats do with echo-location.[52] But putting that aside, I think we can imagine a splitting of consciousness without any images in our mind, but rather just during the occurrence of for example a pure sound experience. Perhaps music, or even just a single tone. And this could be done with smell and taste too, and perhaps even touch.

e. Identical Twins, Free Will and Self As The “Driver” Of The Body

            With this conceptual understanding of what it would mean, or would be like, to go from being one person to two, the next move is to point out that this concept can be applied not just to a person in midlife, but can be applied at any point in their life, all the way back to their origins. Here we leave behind brains, because there is not yet a brain at a person’s origin in gametes or a zygote, and just consider the splitting of an “I exist” or the potential for an “I exist” as a general concept. The easiest way into this is to start by considering a type of splitting that actually occurs in reality all the time and that we are forced to contend with whether we want to or not: monozygotic (identical) twins and multiples. I’ll focus just on twins to keep things simple. Unlike the gamete pairs A and Aa,t, this was already a mystery begging for an explanation to anyone who thought about it (as Dawkins and Jim Holt acknowledge in their quotes in Part I).

            Consider first the situation for most of us, not being a monozygotic twin. (If you are a monozygotic twin, you can imagine that you aren’t, or that your zygote after the split could have split again.) Sperm A fertilized ovum A, and zygote A was created and developed and became one person, person A, you. But now think, in your own case, what if zygote A had split and become two people? Would you exist right now? If so, which person would you be? Some people believe that they would not exist right now, but rather that two new people would. I think this is wrong. Considering the split-brain problem in our own first-person case gives us an easy way to conceptualize the right way to think about it. Had zygote A split, you would be one of the resulting people, but just as in the case of Righty and Lefty, there is no answer to the question of which person you would be. But, most importantly, you would not not exist in that case. A splitting zygote does not cause one person to cease to exist and two others to come into existence. It just splits what would have been one person into two people, just as the split-brain problem does.

            If you’ve already accepting the results of the split-brain problem, then this conceptualization of a splitting zygote should be quite easy to take on board. What comes next might be more difficult.

            Consider now a second situation, where you are a monozygotic twin. Even if you are not an identical twin, imagine that you are. You have an identical twin living in this world now, sitting right across from you in fact. The question you might ask yourself is, if zygote A had not split, would I exist and he/she not exist, or would he/she exist and I not exist, or would neither of us exist? The answer, I propose, is that neither of you would not exist in that case. You would both exist as person A.

            This is likely to be much more difficult to accept than the first situation for several reasons. It seems to leave us with several people, or several wills, trying to operate one body. This makes us, our “I exist” fundamentally seem like passive entities locked inside a body, which is kind of horrifying, and we might wonder what sense we could make of justice and free will if this were true.

            These supposed problems are not insurmountable though, because they follow from an incorrect foundational belief about existence and the self. Let’s look briefly at what this is.

I have affirmed that believing that you exist is the correct belief. There is sense to be made of the idea of existence, independent of the specific content of a brain or life. Though this is true, there is a danger in taking this idea and drawing unsupported conclusions from it, things that don’t necessarily follow. There is a rich history of doing this that stretches back for hundreds of years in fact. This is the specter of Cartesianism I mentioned in Part II.

I’ll switch to a colloquialism many people use as a synonym for their own existence, the term “self”. “Self” is what people often call an imagined fundamental locus of their existence, the thing under all the other factors. It might be thought of as the thing, the bare existence, under the brain-embodied content, to use my formulation. In other words, the locus of your personal existence, or “I exist”. It is an imprecise term though, and attempts to analyze it to find the core concept behind it tend to make it disappear altogether.[53] Nonetheless, a large percentage of humanity have a sense that the term “self” designates something they have or are, something inside of them, as it were, or the even the basic unit of who they are. I think this is probably acceptable in some loose sense and the term does retain some usefulness, but it can quickly lead you astray. This is the primary reason I’ve avoided using it in this essay, though it could easily have been used to label the concepts I’ve been denoting with “personal existence” and “I exist” in quotes.

One such wayward idea is that this self must be a non-physical thing, since it might be conceived as being divorced from content, or, to use Descartes’ term, is “unextended”, meaning it takes up no space. Most people call this supposed non-physical thing a soul.

I think there is no soul, and in this belief I have the support of a lot of evidence and many great arguments, a few of which I’ll explain briefly in a section at the end, after my conclusions. But no matter: the idea of the soul isn’t necessarily the essential problem in the case under discussion, the claim that two people might have been one had things gone differently. A lot of people who aren’t particularly committed to belief in something like a soul still have incorrect beliefs about their self. The foundational one is thinking of the self as the driver of your actions. Many people believe that their self, this fundamental locus of their being, the thing they are talking about when they say “I exist”, the thing that they in fact think they are, makes the decisions and tells their body what to do, such as “move my left arm” or “help that person who fell down” or “steal that bike”.

Along with this belief often comes the belief that this thing, this self, is the thing ultimately responsible for a person’s actions, and should be the subject of reward and punishment. This may be true for some people who don’t believe in a soul, but it is especially true for those who do believe in a soul. Believers in a soul often hold that reward and punishment come (or continue) into the afterlife for this soul. Perhaps heaven or hell, or reincarnation to a “higher” or “lower” being. It is perceived in fact, often without explicit statement, that there must be such an entity for the notion of responsibility to make any sense at all (and again, this goes for soul or no soul). There can be no reward or punishment without some single entity that is ultimately responsible. When, for example, we find out that some physical feature of a brain might be construed to have some responsibility for a person’s actions, we often feel that this takes some of the responsibility off of this self or soul and places it on a merely physical feature that this self perhaps had little or no control over, and this mitigates some people’s feeling of placing blame on the “person”, by which they mean the self. In other words, the person is the self or the soul; the rest is a mere human body.

We can see then how this belief in an essential self would be problematic for the idea that two people could have both existed as one person had things gone differently (had a zygote not split, in the example under examination). What sense can we make of justice or free will if two or more of us who exist now, two or more of these essential selves driving the actions of a body, making decisions and taking responsibility for them and hopefully getting their just deserts (good or bad) for them, could have been one person, could have, rather than being given each their own human body, been given just one? This is a problem even in the case of identical twins we are considering here, even though twins often share beliefs and have similar moral codes. We can imagine a case for example where my twin has done something that I find repugnant while I have taken pains (and made sacrifices) to live a good life. Should I conclude that, had we been one person, I could have possibly been “forced” into doing this thing, or dragged along as this other self occupying my body did it? We might wonder what is the use of trying to live a good life, or what the term “trying” might even mean. And would I then have to accept being locked in this body receiving whatever punishment came along with this horrible deed, even though I myself never would have done it if I’d had my own body? This is not a pleasant thought.

This is a worst-case scenario, but we don’t necessarily have to believe one of the two wills of these cohabitating essential selves would be dominant, and we don’t even have to think of situations involving moral judgment, in order to be confused or unsettled. It just seems like there would be two competing drivers, two competing wills, under the imagined case of an unsplit zygote in an alternate universe. We can simply imagine a left side trying to go one way and a right side trying to go another, each under control of a different one of the selves, for example. Or the two “selves” trying to move a single arm in different directions. This is what the scenario seems to demand.

Yet, this is not what happens in reality. We know this because every person is a non-split zygote. Even for twins who are the result of a split in a zygote, their resulting zygote could have split again. And so, if this was the correct way to look at it, then every existing person would have two, three, a hundred, in fact an infinite number of selves “inhabiting” their mind (there is in principle no limit to how many times a zygote could split). But this isn’t what happens. Everyone experiences essentially one will, or at least one will at a time. Everyone has a single unified self. (I’ll address so-called split personalities and the like in a moment.)

The answer to this puzzle is just that self as driver and decision-maker of the body is not the correct belief. The correct belief is that though there is in a sense a self, because you do indeed exist, and this is a clear and distinct difference from not existing, this self does not control or drive anything. In my formulation I would say it just is existence, in the way I’ve taken pains to describe in this essay. (Since “self” is a colloquial term rather than a technical term, this formulation is not a definitive definition of the term. It is just one way the term might be used among many.[54] This is why I chose my own terminology in personal existence and “I exist”.)

What drives our actions is not this conceptually separated “I exist” that I’ve been talking about, but the actual content of our life, as physically embodied in our brains. Memories, beliefs, desires…all of our folk psychology concepts and/or whatever neuroscientific terms they’ve been replaced with (as eliminative materialists argue for). Your brain drives your body. There is nothing else that does it. And so, unsplit zygote A has one brain and one driver, even though two brains and two drivers would have been created if it had split, and even if the two existences created in that split are contained in that one existence created by the unsplit zygote.

This view makes the “self” seem like a passive entity locked inside a body, with no power, just observing. This makes existence itself like being a prisoner. This is, as I said, horrifying. But I submit that this is still an error of reifying the self, making it into an actual object that exists in the world (this term “world” encompassing both physical things and the imagined possible non-physical things like souls and gods and heavens). All there is to us is the physical brain and its content. So there is no passive entity under that just observing what the brain drags it around doing. There is no dragging. There is just a brain, and the brain is who we are. The self is a concept, sometimes useful sometimes misleading, that we’ve invented and added to that.

To put it another way, the self exists, but it carries with it what has been called the “user illusion”, the illusion that it is the thing driving actions, that it is the “user” of the body, in the way a person is a user of a computer or machine. There has been much philosophy written on this topic, and there is even empirical evidence to back it up, for example experiments that show that by the time a person is conscious of making a decision, it has already been made. In other words, the subconscious makes a decision before the conscious “self” is aware of it, and the conscious “self” then erroneously ascribes the making of the decision to itself.

Perhaps our most visceral objection to this idea is what it does to the concept of free will. Is everything determinate? Do we actually have no choice in what we do? Is there no such thing as choice? Does the quantum world with its indeterminacy somehow give us choice? The question of free will in a purely physical world (i.e., in a world without souls) has been hashed out by philosophers for centuries, and in great depth and at great breadth in the scientific age. One of the greatest of all philosophers, Kant, thought that free will was the primitive belief and that it was one of two proofs of the existence of the noumenal, a world beyond possible experience or empirical access.

I don’t have a developed answer on what to make of free will. In this essay (and for the most part in my life as well) I’m remaining agnostic on whether we have free will, and even on what it means. I’d like to have free will, and it seems like for all practical purposes that I do, but if I analyze it reductively I cannot see how it is possible that I do, or even what free will would mean. I find this bothersome, so I try not to think about it too much. Perhaps this is a cop-out, but I want to have some measure of contentment in my life, and being bothered by metaphysical problems I don’t feel like trying to solve doesn’t accord with this goal. (Being bothered by real-world problems, such as injustice and environmental degradation, on the other hand, should be a part of life whether it disturbs your contentment or not.)

And anyway, I haven’t done much homework on it, though I am quite interested in Daniel Dennett’s concept of “freedom worth having” that he explains in Elbow Room and Freedom Evolves.[55] So I don’t have much to say about it here. One nascent thought I’ve had about free will is to think of the role that concepts play in our freedom, and the way that the concept of knowing we can acquire more concepts in order to make better decisions makes us more free. I think this is similar to some of what Dennett says. I’ve fleshed this out a little, but it would be too big a tangent at this point.

In the end, it may just be a fact that there is no free will as we usually conceptualize it. But this wouldn’t just be a fact about my view of the material world, where in alternate realities what are two separate people in our world could have been “together” in one person, it would be a fact about the world full stop, if it is indeed only a material world. My view of splitting and fusing of personal existences doesn’t change the facts of free will at all. So free will does not affect my willingness to accept the view I’ve accepted here. At most, it makes the already-existing problem of free will more stark. But it doesn’t create any new problems.

To help you tie all of this together, before we move on I’ll give you one more exercise that might help you imagine yourself and another person both existing as the same person, and might help you square how “self” and “will” or “free will” operate in a material world. We’ll step back from zygotes and go back to split brains and split consciousnesses, and apply this type of case to existing consciousnesses rather than those that have yet to come into existence.

Imagine first that in the split brain problem, Righty and Lefty are allowed to each live their lives for, say, ten years after the operation, and then another procedure is performed, whereby each brain hemisphere is taken out of its respective body and they are rejoined and placed together in a single body. They were each separate agents making their own choices for ten years, had pretty well developed identities as individual people, and then they were joined again and once again become one person. At first we might think that there would be two distinct selves each battling the other for control of the new body. But actually, I think the correct answer is just that their two selves would once again become one self, and their two wills would blend into one will. Their two sets of content would blend into one.

Next, imagine this not happening to Lefty or Righty, but to you yourself. There have been documented cases (I think) of people who have lived whole and healthy lives, and only discovered in the middle of this life that they had been functioning with only one hemisphere of their brain; the other was inert. It is especially easy to imagine this happening if these are the conditions under which the person started life, grew and matured. In the case of a hemisphere that ceases to function in midlife, often the other hemisphere will learn to perform functions the now-inert hemisphere was originally responsible for. So we can imagine that a single hemisphere would be even better at performing these functions if it had been the one doing it all along, and hadn’t had to learn it in adulthood. There are many basic functions that appear to be much easier for the brain to learn in childhood than adulthood. So you can easily imagine that right now, you are operating on only one hemisphere. Unless you have gotten a brain scan at some point in your life, you don’t know for certain.

And so the next step is to imagine another person with only the opposite hemisphere functioning to the one you have functioning, and also living a full life. And now, imagine each of the functioning hemispheres, yours and theirs, being transplanted into a new body and appropriately connected. I realize this may be an unpleasant thought for some people, so it is not necessary for you to dwell on it if you don’t wish, but if you can handle it I think it’s quite instructive.

We can make it even more stark: simply imagine a new hemisphere that was of a person who lived a full life up to the present being placed into your own head, replacing your inert one and being connected appropriately to your functioning one. This involves no difference in body to you and no subtraction of your current content, just the addition of a whole bunch of new content. Now imagine waking up as that person.

The details of how this would happen would likely vary with every single case. It is possible that a situation like this, especially if done with two unrelated people, would more often than not leave the resulting person disturbed. It is possible that in most cases it would not. I don’t know, and I won’t try to lead you through further details of what would be the result in your case. But if you wish, you can take it from here, imagining both becoming a single self with this other person, and experiencing a blending of content with them. I think this sheds light on the concepts of self and free will.

In truth, the mechanism isn’t all that important. As with the split brain, these are imaginative exercises of splitting and melding of consciousnesses. Finding an actual plausible physical mechanism for making it happen is a crutch; the real work is purely conceptual.

All of these concepts of these last two sections, including split brains, split consciousnesses, no self, no soul, no driver of the body, and no free will, are ideas I’m bringing to the table from outside of my own philosophizing. They have been around for years, and the views I’ve expressed here are widely accepted (save for what is possibly my original take on the split-brain problem), or at least well-known by those who don’t accept them. As such, I have presented only a very brief account of the arguments and evidence in favor of these views. The arguments and evidence that convinced me of their truth is much larger, and it took me many years of contemplation and assimilation to finally accept them. They are radical ideas. So I understand that if they are new to you, any one of them may be hard to understand or believe, and all of them together may seem to be an absurd offense to common sense, especially on just the sketches of them I’ve provided here. I have not aimed to convince you of their truth, but to just introduce them to you, so you can understand what I base the conclusions that follow on. If you don’t accept these ideas, you may not accept my conclusions about personal existence, or understand them well. But I will press on; you may wish to do further study on these ideas.[56]

f. Split Brains Solution to Compossibility in the Gamete Sorites

            It should be clear now what I believe about gametes A and Aa,t. Speaking in my own case, we already know that the A gametes will produce me if they are joined. They by definition did. But by impeccable reasoning we have concluded that gametes Aa,t will also produce me if joined. What to do? I cannot be both people. The answer is the same as that for split-brains and monozygotic twins: I will be one of those two people, but there is no answer to the question of which one I will be. If the A gametes join and the Aa,t gametes do not then I will be the A person. If the Aa,t gametes join and the A gametes do not then I will be the Aa,t person. And if both sets join, or if they cross-fertilize, I will be one of the two resulting people, but there is no answer to the question of which one I will be, just as in the case of monozygotic twins and split brains. And if we were living in a world right now where there had actually been a set of gametes Aa,t that produced a person under the circumstances I’ve described, I would simply say, at this moment, that it has turned out that I exist as this person rather than that one, as the result of the A gametes rather than the Aa,t gametes, and there is no answer, even in principle, to the question of why I am me rather than him. It has turned out to me that I exist as the result of the A gametes, just like it turned out to me that I became righty when Righty and Lefty were created in the split-brain problem.

            And we can see that the Aa,t gametes are actually just one possible production method for the B gametes. In other words, what we called the B gametes in PD could have been the Aa,t gametes. In other words, we could substitute the Aa,t gametes into PD, and arrive at the conclusion that in fact what we thought was your perfect doppelgänger, person B, would not be your perfect doppelgänger at all, but would simply be you. This is the conclusion we reached with TMT, but in my judgment the sorites is a much more sound and convincing argument.

So we have arrived again, after TMT, at a reason to believe, in a purely material universe, that each of us could have come into existence from a different set of gametes, in other words, could have been a different human body object. As far as I know, this has been judged to be incontrovertibly incompatible with materialism by philosophers, theoretical scientists, and others in the tradition of argumentation by which I’ve arrived at it. (There may be other communities, such as Buddhists, who have reached such a conclusion quite separately from analytic philosophy, about which I will say more later.) So I consider it a significant conclusion, if it is convincing.

It is still a limited conclusion though, having to do only with identical gametes created within the vicinity of the A gametes (which means, by your parents). There are still a great many possible origins for the B gametes I haven’t yet argued for, and there is the question of non-identical gametes as well. But even in this limitedness, the conclusion so far is significant for another reason: this first step, finding any set of gametes other than the A gametes that we could find plausible reasons to believe would have produced you, was the largest barrier in the course of the whole argument. And so the first paragraph of this section is one of the most important in this entire essay. Nonetheless, we have much to add to it yet.

There is an important point about this conclusion I want to be clear about. The Aa,t gametes, if they were to actually come into existence, would not be produced in a sorites process. They would not, in other words, be produced by a process of changing one atom at a time in the original A gametes. They would come about independently of the A gametes, having no more to do with the A gametes than any other gametes produced at that time in your parents. They would have come about just through a normal process of gamete creation, with no unusual changing of atoms and no supernatural forces or anything like it involved. The sorites process was done just to show the connection to the A gametes, but does not indicate anything about their actual creation, or any connection to the Aa,t gametes. It just happened, in this scenario, that two identical sets of gametes were produced very near each other at the same time. The sorites process itself does not exist at all in this scenario, any more than it does in any of the Vast number of scenarios that happen every day.

  1. Could You Have Had Different DNA or Different Parents?

            We’ve gotten over the biggest step, finding a completely numerically distinct object that we believe could have produced you. This was partly the biggest step because of the power of our intuitions, about tracing our existence by tracing a body through space and time, among other things, and also because, as we saw in Part I, compossibility is (or might be; I haven’t found another) the only real reason we have to believe that only one particular set of gametes could have produced you. And we have overcome compossibility (I think), at least in the limited case described in the last section. Having gotten over this biggest hurdle, I could just take the rest for free, could just assume that all of the other criteria for you coming into existence, notably parentage and DNA, must not matter either. It certainly seems this way. But I will argue for them carefully anyway, just to make sure.

So the next question is, could either of these sets of gametes that would have produced you have had any different DNA sequences than the DNA that they did have and still have produced you? In other words, could you have come into existence with different DNA, either slightly different or radically different? The typical immediate answer from most people is simply no. This belief is foundational. As I pointed out in Part I, since the discovery of DNA it has been taken as a pretty basic and straightforward scientific truth that DNA is the explanation for why you exist (or if not the then one of them, and in spite of the obvious trouble monozygotic twins causes). And so different DNA would produce a different person. But I think I have shown how, although DNA does answer the question of why a particular human body object with a certain configuration exists (or, on broader levels, why humanity or animals or life exists), it doesn’t answer the question you are really asking when you ask “why do I exist?” Specifically: we can now see that DNA determines certain things about content, but says nothing about personal existence itself. And so, in light of all this, it seems reasonable to answer this question, could you have come into existence from different DNA, with “sure, why not?”

We might want something a little more tangible than that, though, especially considering how pervasive agreement with the conventional “no” answer is. So let me offer some arguments.

a. The First Argument: DNA is Information

As I mentioned in the section on DNA in Part I, DNA is different from other supposed physical criteria for your coming into existence, because it is just information. It is physically embodied information, to be sure, but all information is (must be), and the part of DNA that is important to us is not its physical structure, but the information it is, the instructions it has for making a particular type of physical body. But it is not in an important sense a body itself. In contrast, parents and gametes are particular physical objects moving through space and time.

Physical objects can be copied, and the copies are just that: copies. They are qualitatively identical, but are not numerically identical; they do not achieve true total “identity” with the original object. No matter how much fidelity the copy has, it is still a different thing. They are separate objects. In contrast, a copy of information such as DNA just is that information. For information to be qualitatively identical is for it to be numerically identical. A copy of the information is the very same information. Dawkins relies on this point in The Blind Watchmaker when he says, “DNA molecules themselves, as physical entities, are like dewdrops. Under the right conditions they come into existence at a great rate, but no one of them has existed for long, and all will be destroyed within a few months. They are not durable like rocks. But the patterns that they bear in their sequences are as durable as the hardest rocks. They have what it takes to exist for millions of years, and that is why they are still here today.” (156)

Now, consider one of our prime motivations for believing in the gamete-dependence claim, which I mentioned in Part I: we trace our existence through space and time by tracing a physical object through space and time, our human-body object. When we trace back far enough, we come to a baby, a fetus, an embryo, a zygote, and then a pair of gametes. The gametes are created from individual molecules, so they are the last physical objects in that backward chain.

The feature of DNA that is salient to us is not a physical object. It is not even really content of a physical object. It is a creator of content of a physical object. It builds a physical object (a human body in our case) into a particular and unique shape, inside and out. That’s all it does. I use this term “shape” to refer to all aspects of the arrangement of the matter of a body, inside and out. This includes the total arrangement of matter of a brain, and so this subsumes even some features that we wouldn’t normally think of as having a shape, such as features of our psychology or personality, since these result directly from the internal “shape” of our brain (and body to some extent). Does this sound too reductive? But what else, on real physicalism, could features of our psychology or personality result from but arrangements of the stuff the physical universe is made of?

But DNA is not the only influence on that shape, of our body or brain. Environment has a huge influence. It influences the shape as it is being built (is every bit as essential as DNA to the body and brain being built at all in fact), and influences the shape as that body makes its way through the world. We’ve already in fact spent a lot of time considering environment as a factor in shaping a human body.

We know that what we conceive of as our existence is independent of content. This essay has gone to great lengths to make that distinction, and I think we should all believe it now. And it is easy to see how personal existence is independent of content created by environment. This is something everyone everywhere believes already. There is probably 100% agreement on this among humanity, a real rarity of consensus. If your parents had moved you to a distance country when you were a child, you would exist there, with very different content. (Some people deny this when put to them as a philosophical question, but I promise you if you tell such a person one day out of nowhere that their parents almost came to financial ruin when this person was five and almost sent this person to live with a family who worked as potassium miners in North Korea, this person will think “holy cow, I’m glad they didn’t do that. I would not have wanted to be a potassium miner in North Korea” rather than “holy cow, I’m glad they didn’t do that. I wouldn’t even exist right now. And it would have been a shame for that other person to have had to grow up as a potassium miner in North Korea.”[57])  Your existence is content-independent when it comes to content created by your environment.

So the question is, why should your existence not also be content-independent when it comes to DNA? You existence depends just on your brain, and your existence can obtain in many different shapes of that brain due to environment. Why could it not obtain if the cause of a difference in shape were due to DNA instead of to environment?

Consider this in terms of the actual shape of your body, and specifically the internal shape of your brain; the location and configuration and functioning of all your neurons. Your brain has a particular internal shape right now due to all the content it contains—memories, beliefs, desires, fears, etc.—accumulated over the years from interaction with your environment. Now imagine your brain if you had been raised on an isolated Polynesian island and were there right now. You would exist, but the internal shape of your brain would be quite different. In fact, though your outer body shape would different in a lot of respects as well, the internal shape of your brain would by far be the most drastic difference. But it would still be you; you would exist; the thing you want would obtain in that case due to the existence of your body, different though the shape would be.

What I am asking you to imagine with DNA is of exactly the same type. Different DNA in an alternate universe would also create a brain with a different internal shape. But since in principle you have no trouble imagining that a differently shaped brain (and body) could be you in an alternate universe if the only cause of that different shape were environmental, then you should have no trouble at least imagining in principle that a different shaped brain (and body) could be you in an alternate universe if the cause of that different shape were DNA. The outcome is the same: a differently shaped brain than the one you have in the present moment. The only difference is the cause.

This is in principle. And imagining this in principle should make us wonder why we have for so long thought that DNA was essential to our existence. That DNA made you you, that you essentially are your DNA blueprint. We’ve known it was just information all along, just content, and we’ve known all along that a particular set of content doesn’t carry your existence through the world. Your existence, the thing you want, persists through changing content every moment. So why do we think it was important at origins?

Perhaps this convinces you in principle. Perhaps you can now as easily imagine being qualitatively different through having different DNA as easily as you have always imagined being qualitatively different due to having been in a different environment. But what about in practice? We need a way, like the gamete sorites, to see that a particular gamete with different DNA would have to have been you, had things gone differently.

I’ve pointed out that our intuition tells us that what carries our persisting existence through space and time is the tracing of a particular body through space and time, all the way back to gametes, whatever shape that body might take at different times. We’ve already swapped out individual atoms from these gametes without changing the structure and examined what we believe, but now let’s make changes to the actual structure or “shape” and see what we believe. To do this, we’ll set aside DNA as information for a moment, and just consider it as a physical structure in the nucleus of a gamete as a physical object, like any other physical structure of a cell.

I would like to focus on the ovum, because what I am going to do relies on our intuition about tracing our body through time and space, and making this intuition clear makes the DS belief seem quite plausible. And for the first step of this argument, I want to find another physical structure—an organelle—inside the ovum that is not is DNA. Wikipedia tells me that sperm have organelles called vacuoles, but I don’t know if ova do. Ova do have mitochondria, but since these have their own DNA, it would be precariously close to begging the question to use them. So I will assume, for convenience, that the ovum has at least one vacuole (I won’t explain the function of vacuoles, because it doesn’t matter). If I am incorrect about this, perhaps a biologist can help me improve my example.

So let’s first think about a vacuole, an organelle in the nucleus of an ovum. We’ll call one of the vacuoles that was in the actual ovum A of our universe vacuole A. Now consider a vacuole B, any vacuole that isn’t vacuole A. Imagine that ovum A is created, same matter, time, place, plan, etc. as in our universe, but instead of vacuole A being put in this ovum, vacuole B is. In other words, the entire architecture of ovum A is built, including the follicle cells, the membrane, and the cytoplasm, and then vacuole B is put into it instead of vacuole A. This is schematic, and probably does not match how an ovum is actually made. Alternately then, we could say that ovum A is built around vacuole B instead of vacuole A. Either way is fine, and I’ll switch back and forth. In reality, the vacuoles are of course probably created in concert with the rest of the ovum, but these schematic renderings make the situation clearer.

I think a great many people would have the intuition that in some important sense the “same” ovum as ovum A could have been built around a somewhat different vacuole, or that a somewhat different vacuole could have been placed into the “same” ovum. In other words, that the existence of the entire structure of the ovum except the vacuole is enough to count it as an object that your body today could be traced back to, whether your body today was in the exact state it is in right now, or if it was in an alternate state today due to a different biography (an alternate world). It’s like anything you are building. If you are building a car, say a blue 1968 Corvette, and have two different engines, say a 427 and a 350, the way you would think about it is that you could put either engine in that car. We have already pointed out that this is just a convention of language, and doesn’t represent anything deeper about sameness, but still, that’s the way we think of it. Tracing your body through time and space is about our intuition of what objects are and are not you, so we are just testing our intuition here. What is it possible for you to believe, or easy for you to believe, would still be your body, or the “seed” of your body, in an alternate situation?

So if you bought this Corvette in 1968 from the factory, and drove it until 1982, you could say, “I’m glad I got the 427 put into this car, rather than the 350. This car is more bad-ass with the 427 than it would have been with the 350.” You can imagine them rolling out the car from the factory without an engine and saying, well Ms. Watanabe, here’s your car, now which engine do you want us to put into it?  In other words, you could trace the body (meaning the entirety of the physical structure, not just the outside portion) of this car from 1982 back to its origin in 1968 in the factory, and you could imagine an alternate scenario in which they had put a 350 into it, and then traced it back forward into the present and consider it to have been this car all along, just with a different engine. We only get in Ship of Theseus type trouble when we start imagining swapping out many different parts. But in this simple case, this one part causes us no trouble. So too then with a vacuole of ovum A.

It’s a short leap then to do this with DNA as well, taking it as just another physical structure of the ovum, with no regard to its eventual function. I’m sketchy on the details of the creation of the set of DNA that goes into an ovum, but I know it is created early on, by a process of homologous recombination in prophase I of meiosis I. This is where random portions of the two sets of alleles of each “gene” (actually nucleotides) in the DNA of the parent creating the gamete randomly switch sides (“crossing over”) and then each separate strand of DNA goes its separate way to create a gamete on its own. This is why every gamete your parents create has a different DNA structure (and although it is in principle possible for them to create two identical gametes, the odds are extremely long).

So early on we have the set of DNA, ready to be “put into” the gamete. (We’ll use “put into” just as a schematic way of looking at it, knowing that in reality it is more complicated.) And so, at minimum, we can easily believe that the crossing over of the very strand of DNA (the same physical object) that went into ovum A in our universe, had gone differently, and then one of the two resulting strands of DNA with a different nucleotide sequence than yours in the present universe had then gone and been put into ovum A, the very same ovum in every way as the ovum A of our universe. (I say “one of the two” instead of “the same” because if crossing over occurs to around 50% of the nucleotides there is no sense to be made of “same”. We could, if we had them arranged say one on the left and one on the right, say that the left one in both universes went on to be placed into ovum A, to get some sense of sameness, even though it wouldn’t really matter.)

What matters here is that the body of the ovum is the same in both cases, our universe and the alternate universe. And it really is the same, as surely as in the case of the blue Corvette. All we have is just some differences in the matter of the DNA that was put into the body. The DNA is just a slightly different object, a very small object compared to the whole of the structure of the ovum, added to the body of the ovum, just like the vacuole was. Just like getting a new heart would be now to you. And so we should have no trouble, on the method of tracing a body backward through time and space, considering this the same ovum.

If you are stickler, of course, we could use the sorites to demonstrate that in principle the specific atoms and the shape of a vacuole could change to the point of being a completely different vacuole, and show that this would force us to believe that no amount of change could affect whether the ovum still brought you into existence. Having established so firmly that an entirely different vacuole could have been in the ovum that brought you into existence, we could then transfer this conclusion to the DNA molecule as a physical object, ignoring its eventual function and information content, and assume the same thing. (A DNA sorites is more complicated, as I will explain in the next section.) And so it’s easy to imagine the same ovum, the same body we are tracing to all the way back from the present, having been given a different DNA molecule.

What happens then? After fertilization, the resulting combined DNA molecule goes to work building a body upward from that original seed of a body. But the information of the DNA molecule builds a very different body shape for it. It is, on the body tracing criteria, the same body, it’s just built into a different shape. Exactly the way we already agree that the environment could have built it, the same body, you, into a different shape. And so, we should believe that the resulting person in either case would be you, exactly the same way we believe the person would be you in the case of alternate universe differences that were due only to environment.[58]

b. The Second Argument: A DNA Sorites

So that’s one argument. Let’s start over and look at a different one, a sort of DNA sorites, ignoring for the moment the previous argument.

With the gamete sorites so far, we didn’t change any content when we changed the matter and moved its location. With DNA, the very thing we want to change is content. And so we have to use units of that content in our sorites; we can’t just take it atom for atom. DNA as content functions at several different levels of discrete units that could be changed, so it will help to get the facts about these discrete units straight first so as to make the argument credible.

The smallest discrete unit of information (content) in DNA is a nucleotide molecule[59]; these are the A, C, T and G molecules (known as nucleobases) that make up the informational portion of a strand of DNA. The next level up of discrete units are codons, also called triplets, which consist of three nucleotides in a particular sequence, CTG or AAA for example. Each codon is the code for creating one specific amino acid, or is a stop signal, and all 64 possible codons code for something. Amino acids are the constituent parts of whole protein molecules, and protein comprises almost the entirety of the structure of your body (by mass, your body is mostly water of course, but the water is irrelevant for our purposes).

The next level up of discrete units in DNA are genes. These are composed of a sequence of codons (and consequently a sequence of nucleotides; there is actually no difference in the gap between codons and the gap between the nucleotides of a codon), each codon coding for one amino acid or a stop signal, and so each gene codes for one whole protein molecule, built from the amino acids that the codons in the gene coded for. So one of the main functions of DNA is to provide the instructions for making the proteins that make your body. The length of a gene varies widely; one gene can be between a few thousand to over two million nucleotides long (and thus up to a little less than a million codons long). An apt and often used analogy is the relationship between letters, words, and sentences. Nucleotides would be letters, codons would be three letter words, and genes would be sentences composed of these three letter words. The entire DNA molecule, or chromosome, would then on this analogy be a book, and a whole genome, all of the chromosomes of an organism together, a multi-volume set. The human genome has 23 volumes.

So from this we can judge it acceptable to use as the unit of our sorites a nucleotide, one single A, C, T or G. (They are actually paired up with each other in DNA, but in practice we can treat them each as single units.) No matter what the codon (three letter word), it will code for something, so any change in any one of the three letters of a codon will still result in a codon that codes for something. The new codon could code for the same amino acid (some amino acids have more than one codon that codes for them), or (more likely) it could code for a different amino, or it could code for a stop signal, in other words a signal saying “this protein is done, starting with the next codon we’ll be making a new protein” (this is the basic idea, though the reality is more complicated). This change in a single nucleotide is called single-nucleotide polymorphism, or SNP, an abbreviation I will use occasionally below.

There is also a lot of DNA that, as far as we know right now, doesn’t appear to do anything—is biochemically inactive. In other words, though it consists of codons that would code for some amino acid or a stop signal if they were put to use, they are never put to use. At present scientists think at least 80% of human DNA is biochemically active, meaning we don’t know what 20% does, and all or some of that may do nothing. Such stretches of DNA could be changed willy-nilly without making any difference to the resulting organism.

It should be clear from this that in some cases even a change to even a single nucleotide, a single letter, of biochemically active DNA would be disastrous for the resulting organism. A single nucleotide swap (changing an A to a T for example) could in principle cause an organism to change from being an organism that will grow into a full adult human being that lives a long and full life, to being an unviable organism that will not grow at all past the first few moments after conception. Or some shortened life span in between immediate death and a long full life, or some other type of health problem. So, when we change a single nucleotide and ask whether the resulting person would still be you, we cannot make the changes in any possible way, because some changes will for practical purposes be nobody, will produce a zygote that would never produce a human with a brain to be somebody. We have to limit ourselves to changes that would still result in a viable organism, and preferably an organism that would still live a long life, long enough at least to be conscious, and ideally though not necessarily, to have the types of philosophical thoughts I’ve been discussing in this essay.[60]

The smallest possible step we could take in an argument would I think be a change in a single nucleotide in non-biochemically active DNA. If sperm A were to have come into existence with one different nucleotide of its non-biochemically active DNA (assuming there really is such DNA), the resulting person would have been phenotypically identical to you in every way (phenotype meaning the actual characteristics of the resulting body, like hair color, facial shape, inclinations of the brain, etc.) Would you be that person? Is “sure, why not?” a good enough answer for you? I think that’s the best we can get here, but I think it’s pretty strong anyway. If you think DNA matters to whether or not you would exist, you should ask yourself whether it matters because of differences in the body it produces, or whether differences in the DNA matter in themselves.

I include this smallest step because it might be significant to some people. Some people might have a knee-jerk intuition that this type of change to DNA, with no change in the resulting body, would still cause them to come into existence, but if they were instead asked out of nowhere whether a DNA change that resulted in a different phenotype, some different characteristic in the resulting body, would still cause them to come into existence, might have a knee-jerk intuition that it wouldn’t. So for some people it might be significant to note that in principle they can imagine their gametes having come into existence with different DNA and themselves still existing as the resulting person, if there truly is non-biochemically active DNA. And if there is 20% of it, then by a sorites they would believe that an entire 1/5 of their DNA could in principle have been different and they would still exist as that person. This might open the door for them to entertain the possibility that their biochemically active DNA could have been different as well.

But to me it makes no difference whether the change is biochemically active or not. I believe the same in either case. So let’s consider some biochemically active DNA instead. Let’s start with the classic example, eye color. The eye color of a resulting person can be changed by a change in just a single nucleotide in a single gene, OCA2. Such a change would be slight, and to account for all the possible eye colors that exist in humans, and the drastic differences in eye color we easily observe (between blue and brown for example) we have to consider more SNPs in this gene, OCA2, and also some SNPs in other genes. But as our first minimal change, let’s just ask this question: if sperm A had had one different nucleobase (A, C, T or G) in the relevant location in its OCA2,[61] would it still have produced you? In other words, could you have had a (slightly) different eye color? Or would this have resulted in a different person coming into existence, very similar to you but with a slightly different eye color, and you not existing?

How does the answer of “sure, why not?” sound here? Once again, I think it’s the best we can do here, but given the fact that we’ve already decided that a whole different set of gametes could have produced you, and that we can’t name a single thing that links DNA to your existence, to the question we are actually asking here, to the phenomenon that is actually under examination, I think it is a very strong answer, in my judgment stronger than the alternative, stronger than the “no” answer. Much stronger.

 It’s not as strong as the “yes” we gave to the similar questions in the matter and spatial soriteses though. The leap is bigger and more significant than just a single atom, both in physical fact and conceptually. And unlike with the matter sorites, there is no essential arbitrariness, either obvious or hidden, in thinking any change to a single nucleotide in your DNA would have resulted in not you but someone else coming into existence. (This is because your DNA does not change throughout your life, unlike the matter and configuration of your body.) I think you could decide just to answer “no” to this question and not be inviting the type of philosophical difficulty into your life that follows you around staring you in the face and not letting you rest.

But I do feel quite strongly about it, that the answer is surely “yes”, because the change is still so small, even if bigger than a single atom, and because of all of the other reasons we’ve encountered in this essay. I could have been born with a different eye color. Had one nucleotide been different to the OCA2 gene of my sperm or ovum A (whichever was relevant to it)—in other words, had the crossing over event of the creation of that half of my DNA gone just one nucleotide different—I would exist right now as this person, maybe having led essentially the same life, with differently colored eyes. I know my parents had in their two genomes the required allelic variations, because my full brother does have (very) differently colored eyes.

So I let this variation into the field of possibilities for things that could have been me, and I think you should too, for things that could have been you. And we’ve done this type of thing enough now that we can see where this is going, so I’ll skip ahead to the end: if we do this, if we allow even a single biochemically active nucleotide to change and still bring you into existence, then this opens the door to all manner of variations in your DNA. In other words, you should believe that you (you yourself) could have been a genetically very different person. Very different in appearance and mental capacities, and have had (or had different) genetic disorders.

c. Conclusions on DNA

Taking these two arguments together with the matter and spatial sorites above, we have moved our conclusion forward to this: you should believe that you could have come into existence from a different set of gametes with a different set of DNA. In other words, from a completely different set of gametes than the A gametes. In other words, any set of gametes that you believe could have produced you if they had had the same DNA as the A gametes, could have produced you if they had had different DNA. In an alternate universe, you could have not only been a different person who was genetically identical to you, but you could have been a completely different person, full stop. Numerically different. Qualitatively different.

This is, I hope, quite shocking. It is radically different from what materialists have thought permissible to believe in the past.

Note that I said only a different set of gametes. I didn’t say any different set of gametes. I’ve only argued for gametes produced by your parents, for example. And only some of them. I never addressed the different seminiferous tubules in your father, for example. And I haven’t mentioned time, because it produces complications which I don’t want to address until Part IV. So we’ll keep time and space vague for the moment.

With this, we should say, any other gametes that your parents produced around the time and near the location of the production of the A gametes could have also produced you. But this gets us to an important new point in itself: since your parents actually did produce a whole bunch of different gametes that met these conditions, this makes the split-brain exercise we did for gametes A and Aa,t, whereby we decided you would be one of the two but there was no answer to the question of which, no longer just an imaginative exercise for a very improbable case, but the truth of reality as it actually happened. Whatever other gametes your parents produced that met those conditions, you could have been one of them, no matter what the DNA, and there is no answer to the question, even in principle, of which one you would be had more than one set united and become a person. And after the fact, there would be no answer to the question of why you are this one rather than that one (your brother or sister). Just as in the split brain and monozygotic twins cases.

But surely, once we’ve gotten to other gametes produced by your parents at a nearby time and location, it is silly to limit ourselves to these factors. I think it is. Just establishing that some numerically and qualitatively different set of gametes could have brought you into existence immediately gets us to all other gametes. The point of the sorites is just to show that some factor that we thought mattered doesn’t actually matter at all. We thought the matter or location of creation or DNA of a gamete could dictate whether or not a gamete could bring you into existence. But now we see that it does not, because we have counterexamples. Once we have even one counterexample, the criteria falls away, and we get all manner of variation in matter and location and DNA for free. If you now do indeed believe there is some group of gametes numerically and qualitatively different than the A gametes that could have brought you into existence, then I think you’d be hard-pressed to find a reason why all different gametes shouldn’t also count under the same conclusion. I think the burden of proof shifts: give me a reason why this difference (parentage, for example) should be excluded.

For example, if a difference could not be reached by a sorites, would that be a good reason to exclude that difference from possibilities that could have brought you into existence? We have such a difference: sex. An X chromosome in a sperm creates a female, and a Y chromosome in a sperm creates a male. (All ova carry X chromosomes to combine with either of these, so that XX is female and XY is male.) The X chromosome is 156 million base pairs long (1805 genes), and the Y chromosome is 57 million base pairs long (458 genes), or about 1/3 the length of the Y chromosome. There is no intermediate between these two, in actual human beings. There is no genetic intermediate between male and female (though there are phenotypic intermediates). There is no sorites that can be done between male and female.

Should we then believe that you could have been a genetically different person, but only one of the same genetic sex you are now? This seems like an extravagant and unnecessary belief.

Remember that the sorites process is never actually performed. There is never any switching out of atoms or genes one at a time, or “rerunning of history” with slight variations. It is just the case that two gametes are created independently of each other, and we believe that either could have brought you into existence. The sorites convinces us of this, but once we are convinced, the sorites disappears. We no longer think of it, it is not something that has to be done to make a gamete be one that produces you. It just convinces us that one could. And once we have one, that is all the work there is to it. Getting to one different gamete convinces us that the factors we thought were important aren’t important after all. And we can then apply that conclusion to all variations on those differences. The sorites is just a form of permission for believing what otherwise might seem incredible.

I doubt there is really anyone who has accepted the sorites arguments up until now but stops short at the leap from one genetic sex to another. But let me really drive the point home, with a sorites of sorites, so to speak. In other words, a smaller DNA leap than genetic sex.

The DNA sorites relies on the assumption that every possible genome of a viable organism of the same sex was reachable one step at a time from your genome, where every genome in between was also a viable organism, like when you change the word “STILL” to “PLATE” one letter at a time with each word being a real English word:







It seems that this is likely true for the human genome, but perhaps it is not. Perhaps, in order to get from you to certain other people of your same genetic sex one nucleotide at a time, there is inevitably one sequence that does not produce a viable human being. If this were the case, would it matter? You’d have to convince me that it does. If it were true, this would be a contingent fact. Just pure happenstance. And it could change, if humanity evolved. The gap could disappear. And the fact of this gap would have nothing whatsoever to do with either of a set of sperm on either side of this “gap” in the sorites. Again, the sorites is never actually performed. These two sperm just come into existence independently of each other. Would you really want to believe that, if they could be connected through some elaborate invention of our minds, the sorites, that they could both be candidates to be you, but if not, then only one could? And so, if you accept that two sperm of the same sex unconnectable by a sorites (if there were such sperm) could have produced you, then there is no reason not to accept that a sperm of a different sex could have produced you.

And so this all applies to the criteria of parentage as well. I believe I could have come into existence from different parents, and the reasons I just gave are the reasons I believe this. I don’t need an additional argument for parentage at this point. I don’t need a sorites of parentage.

But one can be done, actually. And I’ll show you how to do it, even though I think it doesn’t much matter. I’ll do this because I want to squeeze every last drop of usefulness out of the sorites. Also, because parentage is one of the three main generally accepted criteria of coming into existence that we established in Part I, and so perhaps some people have a lingering sense that parentage does matter, independently of all other considerations.

I warn you though, this section really is tedious. Mercifully, it is also short. At least, much shorter than I could have made it.

d. Total Spatial Sorites: Other Parents


“[Y]ou can change anything to anything by easy stages through some connecting series of possible worlds.” –W.V.O. Quine

I’ll start with a simpler exercise before I get to different parents: the seminiferous tubule. So far in the spatial sorites, we have only reached a sperm produced in the same tubule as the A sperm, and maybe a similar case for ovum A. We could not do a sorites to a different tubule so easily. Our trouble is that, though the total length of all the seminiferous tubules is 300m, they are discontinuous, each being about 60cm. So strictly speaking a spatial sorites cannot be done “around the bend” so to speak from one tubule to another. And there is another, even greater gap I haven’t yet brought up: men, of course, have two completely separate testicles.[62]

First, tubules within a single testicle. We can do a sorites transforming one tubule into another, at least within a single testicle. As in, “if tubule X had been just one increment in this direction, and/or been composed of just one different atom, would it still be the ‘same’ tubule, in other words, have been a tubule that could have produced a sperm that could have produced you?” Eventually, we get to a point where tubule X in this alternate universe is in every way identical to some other tubule in our own universe, say tubule Y, and so a) what started out as tubule X is tubule Y for all intents and purposes and b) now the original tubule X can exist right beside it in its original position in our own universe. And at every step from tubule X to tubule Y, one of our sorites sperm could have been produced that we have concluded would have produced you, while the original tubule X would still be a tubule that could have produced a sperm that could have produced you.

I told you it was tedious. It’s a small question, whether a sperm from a whole different seminiferous tubule could have produced you, and only arises because of contingent facts about the actual method of production of sperm (and maybe ova). And the same is true of the separate testicles. But demonstrating this tubule sorites helps us with the leap to different parents. (I won’t bother considering the separate testicles on their own, since different parents will subsume that conclusion.)

First, remember that you held the parents criteria mainly because you unreflectively assumed that only your parents could have produced your sequence of DNA. But we now know that this isn’t strictly true. Other, genetically different parents could have produced the DNA sequences of each of the gametes that produced you, though the odds are astoundingly long. And your DNA sequence could have been produced artificially in a gamete. So the main reason for taking parents as a criteria is already out the window. And now we know that DNA is no longer a criteria anyway. So even the reason that parentage was a reason is out the window too. But let me sketch the idea of you how to do a parentage sorites anyway.

Consider two men of the same age sitting next to each other. They have to be men, because we want them both to be producing gametes right now, and women produce all their ova when they are fetuses, and so could not be sitting, though they could be next to each other if they were sisters, but we don’t want to talk about sisters, we want to talk about completely unrelated people. Anyway.

It should be easy to see how, for a single moment frozen in time, a spatial, matter, and configuration sorites could be done between man A and man B to transform one into the other. We’ll just transform A into B, and assume the original B disappears somewhere along the line. And we’re just doing this to the body; we will not then reflect on whether this new person B would be person A “inside”, but just go from one body to the other via a sorites.

Encompassed within this sorites of the whole person, will be a sorites of any sperm that man A was creating. This sperm sorites will then be just like the sorites I laboriously performed in section 1 above, only over a much longer distance. And so, if man A was your father and was at that moment producing sperm A, a sperm that produced you, then the man B he “becomes” will at that moment still be producing a sperm that would produce you.

Perhaps this is too easy for you? Don’t the histories of these two men matter? Isn’t that what makes the parentage intuition powerful, that the identity of the man who was your father depended on his origin, not just on the fact that someone with his exact configuration was occupying that space and time? It matters that the man we called man A at the end of the sorites got there in the same way your father did, and that man B did not. After all, on belief in the gamete-dependence claim, we found that we could not definitively answer the question of whether you would exist if one of your parents had been a perfect doppelgänger. So this sorites begs that question, if you’re not already convinced that the gamete-dependence claim is wrong.

True. But it’s a first step to conceiving the whole thing. We can also do a sorites of time, throughout all the history of this universe and alternative histories of this universe. Consider all the “moments” that have happened since, say a few weeks before you were conceived. I put “moments” in quotes because there may be no precise meaning to a single moment. But we can imagine what it means to say, stop time right now and just consider this moment. At this moment, all the matter in the universe is in one configuration. But let’s go easier on ourselves, and just consider all the matter on earth. It is in one configuration at this moment. And the previous moment, it was in a slightly different configuration, and the moment before that… etc. all the way back to a few weeks before your conception. I’ll call these “moment slices”, the configuration of all the matter on earth at a particular moment. Each moment slice has two adjacent moment slices in the time we are experiencing.

Each moment slice also has adjacent moment slices in space: two slices of the same time, but of different possibilities for what could be obtaining at this very time. If you don’t believe in the multiverse (particularly the quantum multiverse), then these moment slices adjacent to this moment slice in space aren’t actual, but are only possible.  If you believe in the multiverse, they are actual also. But I’ll stick with assumption that most people hold, that they are not actual. Even with these moment slices being only possible, this still defines a four-dimensional conceptual space (three dimensions of space and one of time) of a Vast number of moment slices each surrounded by a Vast number of moment slices only a single sorites step away. And in this way, you could follow a sorites of your father through time and space, both actual and possible, as he gets created into any different person at any time, and thereby remains, one small change at a time, a man who could bring you into existence, on belief that parentage matters.

There is an apparent gap in this four-dimensional sorites. In order to honor the origin and history of the human beings, we appear to have to trace your father back to before he started sperm production, in order to go forward as a different human being. In this case, rather than asking “is a particular sperm he is producing a sperm that could have produced you?”, we have to ask, “is that human being still a human being that could eventually produce you?” If you follow the sorites, it will be. Since we already have the conclusion under out belts that you could have come from a numerically and qualitatively different sperm from your actual father, then a supposed potential to generate you within him appears to be the only remaining factor he has making those sperm special. And so we should see this potential then carry over into any other man he can be connected to by a sorites, which is to say, all men.

This is the method at least. I won’t walk you through all the details, because, as I said, I don’t find this total spatial sorites particularly interesting or important. I would believe in coming into existence from other parents even without it. I just wanted to show how the method can be done, if you want to play with it. Perhaps there are other problems with it? I haven’t thought it through enough to find them, but please do bring them to my attention if you do.

One might wonder, if we had the conceptual space of the total spatial sorites available to us all along, why we bothered with all the other stuff. It is because the total spatial sorites is a bit glib, and I think most people wouldn’t take it very seriously on its own. Quine meant his statement I quoted at the start of the last section as an insult.[63] A sorites or other such argument of small increments can be a sort of joke if we don’t have independent reasons to believe its conclusions.

But we do have many independent reasons. We have all the incredible beliefs and contradictions that follow from belief in the gamete-dependence claim in Part I.[64] So the conclusion from the sorites becomes appealing. And we discover that a very simple sorites, like the ones for space and matter on the gametes, is easy to believe. Once we have this, all else falls away.

To sum up then, this is our new, previously incredible belief: There are compelling reasons to believe I could have come into existence as any number of different human beings, both numerically and qualitatively different, and from any source, and this is a much better belief than the alternate one that I could not have been anyone but this human body which came from that one particular set of gametes, because this alternate belief leads to us to make ambiguous choices between what could and could not be me, and it offers no reasons for believing it other than the brute fact that I exist as this person now. But we need good reasons to believe things could not have been otherwise. Simply that we know they are that way now is not enough. I don’t think we have such good reasons. The problem of compossibility was thought to be one, but we can see now that it can be overcome through the conceptualization of splitting consciousnesses and therefore splitting existences that the split-brain problem provides a crutch toward understanding. And so compossibility is not a problem after all, and so it is not a reason to not believe what we are otherwise compelled to believe, that I could have come into existence as any number of human beings from any source.

In Part IV I will examine some of the implications, complications, and consequences of this new belief.

Part IV: Better Beliefs About Your Personal Existence

  1. The Minimal Conclusion: If Things Had Gone Differently

a. The Minimal Conclusion

            The world could have gone quite differently than it has. We believe this in our bones. Even if we see no way around total universal determinism, we still believe this, and live every moment of our lives as though it is true. And so I give you the following story.

            Imagine that starting on January 1st in the year 1900 things had begun to go slightly differently than they actually did in our world. Everything up to 1900 went exactly as it actually did for all of human history, all the history of the universe in fact, but in the year 1900 small changes from what actually did happen happened instead. And by this passive “happened” I mean that people did different things.[65] A woman in Gothenburg who in our actual world left her house at 11:31am to do her shopping, in this alternate world leaves at 11:32. That apple she grabbed in our world was nabbed 30 seconds before she set eyes on it in this alternate world, and so she buys a different one. A farmer in Turkestan leaves the last bite of his breakfast on the plate, instead of eating it like he did in the actual universe. His wife eats it while washing up. A herdsman in Bolivia wakes a minute earlier and thereby catches a glimpse of a wound on the shank of one of his alpacas. He goes over to inspect it straight away, putting off relieving himself behind the bush for a minute longer than he did in our world, where he didn’t notice that wound until after 9:00, because that alpaca had been turned the other way when he woke in our universe. A little girl in Mozambique runs outside and mis-steps just slightly, tripping over a root. She is okay, just a little scratch, but it’s a scratch she never got in our world, because she was surer footed at that moment in our world.

            Every person throughout the world does something just slightly differently on this day in this alternate world. For some, their Monday, January 1st 1900 is still about the same on the whole; the changes are minor details, and they end the day much as they started it. For others these tiny changes in their lives and the lives of everyone around them lead to a drastically different day by the end of it. In either case, though, every one of these changes, small and large, has a very big impact in one way: by that evening, and in most cases much earlier, every person in the world having sex that day does it at a very slightly different time and in a very slightly different way than they did in our actual universe. Consequently, in every case in which a conception occurs in both worlds, a different sperm fertilizes the ovum (this is not what would necessarily happen in every case, but it is certainly possible and not unlikely, so let’s say that it does), and in many cases conceptions occur there where they didn’t here or not there where they did here. What’s more, a few people find for very small reasons that the ostensible “completion of the act” or perhaps even any part of the act itself, is not be attained in this world, where it was in our world, and others who for whatever reason in our universe did not have sex at all, or found some impediment in the middle of the act that prevented this so-called “completion”, find that they do complete it in this alternate universe. The consequence of all this is that every human being who is born nine or so months later or after in this alternate world is a human being that doesn’t exist in our world, taking “human being” here to mean just a particular human body object with a particular genetic code, and no human being conceived on or after January 1st 1900 in our world exists in this alternate world.

The differences between our world and that one compound every day after January 1st, long before any different children are born even. Further, in less than two decades human beings who don’t even exist in our world at all begin having children of their own in this alternate world. And so, all the human beings conceived on or after January 1st in the year 1900 in this alternate world and for all of subsequent history are different from any that existed in our world. By the present date of writing, records indicate that this alternate world shares only three or four human beings with our world, the oldest human beings on the planet, conceived in 1898 or 1899. There may be a few others in places without birth records, but it is likely that by the time you read this there will be none at all.

            What has happened and is happening in this alternate world? The year 1900 is well after most of the principle actors of both World War I and II were born. So let’s assume both happen, and with the same main characters. Hitler and Churchill and Roosevelt and Mussolini all go head to head in Europe. Only poor Hirohito in Japan does not exist. A different human being becomes Emperor of Japan after the Taisho emperor dies. But all of the Japanese generals of WWII do exist, and so we are free to assume that Japan behaves more or less similarly during this time.

            But most of the soldiers in WWII are different human beings. As are their wives. And Rosie the Rivetter may exist in this alternate world, but if she was inspired by a real human being, it is a different human being in that world.

            But let’s say, for no other reason than to be vivid, that the broad currents of history even in the 2nd half of the 20th century go basically the same way that they did in ours, just with different people enacting them. There was no Rosa Parks or Dr. Martin Luther King, Jr. or Malcolm X, but there was an African-American civil rights movement. Singapore becomes an independent state on the tip of the Malaysian peninsula, but there was no Lee Kuan Yew. The Cultural Revolution in China happens (Mao was born in 1893), and then the country embraces capitalism in the 1980s, but all of this is done by and happens to almost entirely different people. There is a counterculture of the 60s in America and elsewhere, with hippies and drugs and all the rest, and there is rock music, but there is no Chuck Berry or Elvis, no Beatles, no Jimi Hendrix; there’s a completely different set of songs and compositions and performances by different writers and musicians, though stylistically they are quite similar and many of them bear uncanny resemblances here and there to the ones we have. Japan makes great cars and electronics, but none of them are called Honda or Sony. There is no Star Wars or Jaws, but films, and especially blockbuster special effects films, become a huge part of worldwide culture anyway. Somebody walks on the moon, at some point.

            And so we look at this alternate universe in 2016. There’s well over 7 billion human beings on the planet, and these 7 billion human beings, entirely different than any that exist in our world (save for those few oldest), have the internet and handheld computers and global warming and some of the rich and powerful countries engage in hegemonic aggression and some of the less so engage in terrorism, some along religious lines.

            And here’s what I believe about those 7 billion human beings in that alternate world: I am one of them. I exist in this alternate universe. I am some person, one of those 7 billion. That world would not be going about its business without me in it as an observer, just as I am in our world. I have different genes in this alternate world, and different parents, and a different upbringing, and consequently I am very different in content. But I am someone.

Who am I? Which person am I? Even if we had a list of every human being who exists there and knew everything about where they came from tracing all the way back to the morning of January 1st 1900, we could provide no answer to this question, not even in principle. It is the same as the case of the split brains. If my brain had been split last year, or if my zygote had split after conception to form identical twins, there is no answer to the question of which of the resulting people I would be. But I would be one of them, just in the sense that I would exist. I would not not exist. The thing that I want, the very thing I want, that obtains right now in this universe and has obtained during the lifetime of my human body and that I have every reason to think will continue to obtain in the future of my body, would obtain in that alternate universe. In exactly the same way it would obtain had the world and me only begun to differ last year rather than in 1900, and so the human body called Joe Kern was only slightly different than it is now.

And I mean all of this as being the case in a purely material world.

This, I think, is the inevitable conclusion of everything I’ve argued for so far.

If I were being as careful as I should be, I would be talking about being any conscious organisms here, or even any physically embodied consciousness (and I believe that physical embodiment is the only way for consciousness to exist), not just human beings. But that is a complication I’d rather leave until later. So I will focus just on being a human being that came into existence in the normal way, via gametes, here in these first few sections, this “minimal conclusion”, and you can carry with you through them the understanding that in the end I mean more than that.

Is this really a new conclusion? It may appear that some well-known philosophers have predicted this belief, or even taken it to be an integral part of their system, or would take it to be an obvious consequence of their system, if not explicitly stated. Two example I can think of are David K. Lewis and his counterpart theory and Daniel Dennett and his reduction of consciousness. But I don’t think this is so. I’ll save my discussion of this for part V though.

I would almost think that Parfit’s well-known and thoroughly argued views on personal identity entail it, a point I will also explore in section 2c. But in fact Parfit explicitly denies it, immediately after stating and affirming the gamete-dependence claim (which he called the Time-Dependence Claim). He takes a quote from the memoir Period Piece by Gwen Raverat, granddaughter of Charles Darwin. She says:

It is always fascinating to speculate on who we would have been if our parents had married other people.

Parfit replies:

In wondering who she would have been, this woman ignores the answer: ‘No one’.

But even without this explicit denial, the gamete-dependence claim itself would be a denial of it. But it is convenient that Parfit so explicitly denies it (rather than having to rely on the more tortuous DS acid test to ascertain his belief). Being explicit about it gave the clear chance for someone to challenge it. But no one ever did, as far as I know.

Some people, as I’ve said, would claim belief in the gamete-dependence claim and also accept this belief. But the two are irreconcilably incompatible. So no careful thinker would allow him or herself that.

Dawkins gives almost as explicit a denial of it as Parfit does, in the quote I gave in Part I. And all the other writers I mentioned in Part I indicate that they would explicitly deny it if it were put to them. I think no materialist, in the Western scientific and analytic tradition of materialism at least (I will talk about Buddhism later), has held this belief before. So again, I think it is indeed quite new.

And I will go further: I think this belief, that I would be one of the people if the world had gone differently, is necessarily so. It is necessary that I would be one of the people in that situation. In other words, it is impossible that I would not have been one of the people that situation.

Why necessary? Perhaps, even before reading this essay, you would have thought you could have been one of the people in such an alternate situation, though you had no reasons for thinking one way or the other. We do this all the time, and quite naturally; if you read or watch and alternate history such as The Man In The High Castle, you imagine yourself in that world, even if the difference (the Axis winning WW II) would have prevented the particular human being you are from being conceived. We do this with all fiction, but alternate histories are particularly stark. So the idea has been in your mind all along, even if you never analyzed it. And then, after reading this essay, you may find you now have many good reasons for believing you could have been one of these people. And so you find it easy to believe, understanding why and even sort of understanding how it comes about. Perhaps you even find it very difficult to believe that you could not have been one of those people, to believe that it was impossible for you to have been one of those people. But to believe that it was necessary for you to be one of them, that it is not possible that the world would be populated with any group of 7 billion human beings and you not to be one of them, seems too extreme, too absolute. How could it really be necessary?

Because if it is possible for you to be someone else, it must be necessary that you would have been if your particular human body hadn’t come into existence. Otherwise, you will have to argue that you would be someone else in some situations where other human beings other than the one you are now exist, but not others. You can probably see immediately how arbitrary this would be. You would have to find some criteria, some reason, for existing in some situations but not others. Something that caused you to exist in some situations but not others. I can appeal to the failure that I’ve already demonstrated of finding such causes, the failure of finding such reasons that a particular human body should or should not bring you into existence. But you might not be feeling those reasons so strongly at the moment, and they might be too tangentially related anyway. We can just focus on the situation at hand, though. What would be necessary in the description of an alternate world (including its history) such as the one I’ve described for you to feel sure that you would be in it, or even to feel that there was a chance you would be in it? Or what would be a red flag in a description of such an alternate world that would indicate to you that you could not be in it? There could be no such thing. Either you absolutely would not be in it, as is believed on the gamete-dependence claim, or it is necessary that you would be in it.

But you are correct that this seems extreme. It seems obvious—too obvious to even remark on—that of course it could be the case that there were a group of 7 billion human beings and you were not one of them. After all, imagining other people existing and you not being one of them is the easiest thing in the world. And so if necessity follows from possibility, then maybe possibility really is wrong after all. Maybe the gamete-dependence claim should not be denied after all.

This is a natural reaction. And so we should rehearse the reasons that we denied the gamete-dependence claim, if we really want to convince ourselves that it is not so hard to believe that it is necessary that I and you would be someone in the alternate world I just described.

b. The Arguments Against the Gamete-Dependence Claim, Rehearsed


            We start in the middle, with the fact that you do exist now, which I established in Part II. The thing you pick out when you say “I exist”, the thing you want, obtains right now. It must, by definition, and it cannot be diminished by calling it imaginary or any other such thing. And it obtains throughout the life of your body, as long as your brain is conscious, and this cannot be diminished by calling into question any connections between your body now and your body at different times.

            So we then look for a reason that this obtains right now. It didn’t have to. There are many possible ways the world could be right now where this does not obtain. Originally, on belief in the gamete-dependence claim, this was obvious. We didn’t even need PD; any world in which the A gametes weren’t created or didn’t join was a world in which you didn’t exist. PD just made this stark, by showing that your existence could be abstracted as a different object of examination than the content of your life. In other words, that your exact same content could exist while you didn’t; someone else could have had your content. But now the gamete-dependence claim is in question, so if we can we should avoid relying on it to establish that, though you do exist now, you might not have. And we can.

            If there were no human beings in the world, no conscious life, then you would not exist. You did not exist during the billion or so years after the big bang, at least, when there was no life on earth (and presumably nowhere else either). That is a long stretch of time in which you definitively did not exist. And, the world could have gone different than it has. This is true starting in 1900, and it’s true starting all the way back then. The universe could have gone such that it would contain no conscious life at all right now. In which case you would not exist right now.[66]

            But you do. And so this is something that requires explanation. In other words, something that must have an explanation. There must be a reason for it. Something that caused the fact to go from being one way, you do not exist, to the other, you do exist. There would have to be one. Nothing changes without a reason, or explanation. Without a cause, no change happens. Things just stay the same. The fact could not go from you not existing to you existing without a reason.[67] So there must be an explanation.

            If we deny the gamete-dependence claim, the explanation is easy. You exist because conscious organisms exist, and you will exist whenever conscious organisms exist. And we know well the explanation for the existence of conscious organisms. (I will cover it briefly at the end for those who don’t.)

            But we are reviewing the reasons we are denying the gamete-dependence claim, for the very fact that we find this result hard to believe, so we cannot take this easy way out. We have to see why the gamete-dependence claim does not answer this question of why you exist right now rather than not.

            So on the gamete-dependence claim, the only thing that has to happen for you to not exist is for the A gametes to never be created or to never join. Any number of human beings can come into existence before, during and after the time the A gametes were created and joined in our universe, but if none of them come from the A gametes, then you will not exist and never will. That was your only chance. No other possible event throughout the rest of the time of the universe, and no other possible event in any other universes, could have brought this existence about.

            So there are cases where you exist, and those where you do not. What distinguishes the two? Just the A gametes. So what is the explanation for this? Why do the A gametes distinguish these two situations? What is it that makes these A gametes bring you into existence? Why are these the ones, but no others?

            And here we recall the attempt to find such reasons from Part I. We recall that we could find no such reasons. Before this essay, DNA and parentage were frequently given as reasons. But now we remember that they are no such thing. There is nothing about DNA that can explain why you exist. A human being of your exact DNA could come into existence and not be you, on the gamete-dependence claim. Or it could be you. (One was). What is the difference between the two? What is it that caused the fact to be one way rather than the other? There is nothing that can be found. Parentage falls to the same fate. Neither thing is the sort of thing that could explain why a particular object brings you into existence rather than not.

            There were other hidden criteria for the gametes that we brought to the surface. Things like time and location of creation, or the matter used in creation. But we recall now that none of these had any more explanatory power for your existence than DNA and parentage did. Pointing at gametes with a specific set of properties and saying you exist because these existed is no better than pointing at your human body now and saying you exist because this exists. We can see that, okay, it is true, but it is no explanation. It is not an answer to the question we want an answer to. An infinite number of gametes identical to your A gametes could exist, and it must be the case that either one pair of them would bring you into existence, or none of them would. What would be the factor to either make it the case that one pair would bring you into existence, or the case that none would? And if one pair did, what would be the factor that made that one bring you into existence rather than any of the others?

            So we remember that on the gamete-dependence claim, though there are clear cases where human beings exist and you do exist and many other clear cases where human being do exist but you do not, there is no explanation for why some situations (or one situation, depending on how you think about the time before the creation of the A gametes) did or would have brought you into existence but others wouldn’t have. There is no cause to be found.

            And then we remember that there was a purported explanation for this: the indexical view. I gave this another name, the Butlerian view: everything just is what it is and not another thing. But I will focus on the indexical version this time. This is just that “I exist” just marks out one point in time and space from which there is one perspective observing. The analogy is that we do not need to ask why now is now. It is not an amazing fact. Every moment it has to be some time and not any others. The indexical view claims that “I exist” is just the same. Every conscious being at every moment, or every observing perspective at every moment, has to be marked out by an “I exist”. It would be impossible for there to be one without that (whether the conscious being had language to express it or not).

            And so I say: I agree with this. Existence is an indexical fact. But this belief is coherent only if we deny the gamete-dependence claim. It fails if we try to hold onto the gamete-dependence claim. I will remind you of why.

            For the indexical view to be true, all of the “I exists” that exist now or ever have existed or ever could exist must be marking out different instances of exactly the same thing, just like time does. There are no breaks in time, where one category of time is going along for awhile, and then suddenly that one stops and another one starts. And this is true for transworld times too. It is all the same thing. But on the gamete-dependence claim, existence does have these breaks. There are portions of actual and conceptual space where many different indexical points of “I exist” are all the same person, the same thing, are the thing you want besides content obtaining, equally throughout that conceptual space. For you, these are your past, your future, and all of the alternate lives you didn’t live (such as going to France, or a Polynesian island, or having got up an hour ago to get a cup of coffee). These are all the same “I exist”. Within this frame of possible and actual events, your “I exist” is just like time. It is the same thing just at different points. It is an indexical. And so to make all of the “I exists” be simple indexical facts, we have to make them all be this same “I exist”. If indexicality is to be an explanation to you of your own existence, then the “I exist” of all these other human beings has to have the same status to you as your present, past, future, and alternate lives that you didn’t live. Otherwise it is not an explanation of why you exist. The question of why you exist remains unexplained, on the gamete-dependence claim.

            When I think of this, I picture a diagram like this:

Life Curves.png

            Each line within each enclosed shape represents the actual life of that person. All of the empty space represents possible lives of that person that they did not or will not live. (It’s a pity about Person G.) A diagram such as this makes it quite clear: within each enclosed space, each point represents the same thing, the same “I exist” (the same thing that person wants obtaining). But when we get to a point in a different enclosure, it is a completely different “I exist”. This is the belief of the gamete-dependence claim. It is clear that indexicality could never be used to explain such a phenomenon, this “I exist”.[68]

In other words, on the gamete-dependence claim, there are many other “I exists” that are completely different things. (This is the very content of the gamete-dependence claim, after all.) But indexicality cannot be the explanation for two different things like this, where one is the same thing over one broad spectrum of possibilities and the other is the same thing over another. Indexicality doesn’t explain between those two things. It only explains within each one.

In other words, the indexical concept works only if there is literally no difference between you and another person besides content, in exactly the same way as a different time of your life or alternate life (or just simply a different on a timeline of the universe). The gamete-dependence claim clearly and definitely adds something aside from content. In order for the indexical idea to work as an explanation, there must be no difference between a) the possible you in an alternate situation where, for example, you had skipped work this morning instead of coming to work, and b) any person who might have existed but didn’t, or c) the alternate biographies of any existing person, aside from all these human beings having different content than you, to differing degrees. There must be no additional concept to add to that content. But on the gamete-dependence claim, there is. In alternate situations after the creation of your gametes and zygote and child, etc., there is a same thing that obtains, your personal existence, in many different objects. In alternate situation before the creation of your gametes, this thing does not obtain. So this personal existence is a different entity, an additional entity, to these objects. And this is true of all human beings. Conceptual space is full of fences surrounding spaces of possible objects that are all one personal existence. So, on the gamete-dependence claim, personal existence is not an indexical concept, because it obtains at more than just one point, but not at every point. The only way to make it an indexical concept is for it to obtain at all points.

And so we should treat all “I exists” just as we do our own, as the same thing as our own.

            But we might wonder how we can do this. What sort of mechanism would allow us to? One is the sorites. We recall doing the sorites, changing the creation of the gametes by one atom and one increment of space at a time, and finding that, in order to believe that a completely different set of gametes would not have brought you into existence, we have to select a completely arbitrary point along this continuum and say that that is the point where you would no longer come into existence. This arbitrariness is very unappealing in itself, and even more so given the fact that on the gamete-dependence claim there is no explanation for your existence anyway, and so we have no strong reason to want to pick out a place, whether it was arbitrary or not.

The sorites also reminds us that we don’t even know what we mean when we say “these gametes” anyway. We don’t know what criteria we should use to make sure they are those gametes. This is a problem because all kinds of change to the physical object of your body (all the way back to the zygote stage) is admitted while your existence still obtains, but no change would be admitted to the creation of the gametes while they still brought you into existence. And so, to select even one atom difference to be the change that would cause the gametes to not bring you into existence is arbitrary, even though at first it might seem it would not be.

            And then we recall that the idea of fading existence as a gamete changes from one to another is hard to understand and problematic. And I can add something new: it doesn’t help us explain your existence anyway. It doesn’t solve the mystery of why you exist from these gametes and no other, or why you exist from these gametes rather than not existing at all from any gametes. It still places your existence within a fence, though one with vague/fading borders.

            And so, remembering all the reasons that the gamete-dependence claim should fall, we now understand that denying it means that it is possible for you to have come into existence from a different set of gametes. Possibility means that there is at least one other set of gametes that could have brought you into existence. And it is then easy to see how this possibility then leads to necessity. It would be arbitrary to conclude that one or some other gametes would or could bring you into existence, but not others. One way of seeing this is the universal sorites, but I think we don’t even need that, once we understand the principle. We need a reason not to believe some set of gametes fall within the category of things that would or could bring you into existence, rather than a reason to believe it. Or a reason to believe that no gametes at all would bring you into existence in certain situations. I think no such reasons will be found. So we are back at necessity. Any set of gametes could bring you into existence just as much as any other, and so whatever set of gametes there are, you will exist as one of the resulting people.

But still, we can see all this and still feel that this claim of necessity seems too strong. We see all the trouble with not believing it, and all the connections, but it is hard to believe in our bones in this necessity.

Part of the trouble is that, as I said, it is after all very easy to imagine there being people but you not being one of them. We start by just imagining no people or any kind of conscious organisms existing at all. It is a fact that this was once the case. Long ago, there were no conscious organisms at all. And so none of us existed then, though the universe did. So, given any stretch of time, it is not necessary that you exist there. Your non-existence is still a thing, a thing that has obtained in the past and may again in the future.

            So how can it be necessary that you would exist as soon as conscious organisms exist? How could it be impossible that you would not be one of them? You simply imagine some people coming into existence, but not you. There they are, you are nowhere. This is how you live your life all the time. Any place there are people but not you, there they are but there you are not. (Omaha, Lyon, Mito, Almaty, Ndola, take your pick.) There are many such places in the universe right now where you are not. So it is easy enough to just subtract one more, where you are now, and give it the same status as all these other. To go from “you are in one place while other people are in other places” to “you are in no place while other people are in places”. This seems like the easiest move in the world.

            But then we remember the thing that made you come into existence, the creation of the human body you are now. And you remember what you imagine of all these other human bodies that are not you: when they come into existence, they do not bring you into existence. They exist right now but you do not. And you find that you can just as easily imagine this of your own human body as of any other human body, can just as easily imagine that your human body came into existence without you coming into existence. That your human body exists right now without you existing. Something is fishy here.

            This is the sort of fishiness Nagel described, that loses some of its resonance when we try to put it into words. One way to put it into words would be that it is no more or less necessary for you to have come into existence with this human body than with any other. Therefore, if, as actual reality has shown, it was necessary for you to have come into existence with this human body, then it was for any human body. I think this is true, but stated as a dispassionate proposition with a conclusion, it loses some force. It almost seems glib, or sophistic. I don’t think it is, but it can seem that way. Better is just the inchoate fishiness of the previous paragraph.

            And finally, we remember the split-brain/split-consciousness solution to the problem of which person you would be. If all gametes have equal status as being gametes that could bring you into existence, then how does it get decided which you will be? It doesn’t get decided. There is no such thing. There is no answer even in principle of which you will be, or why you became who you are. Just as there is no answer of which person you would be right now if your zygote had split, or why you would be that person and not your twin. And the same is true of the splitting of the hemispheres of your brain, though the possibility of such an operation is controversial. It doesn’t need to be true, it just needs to be something we can conceptualize. The splitting of the brain was just a crutch to help us conceptualize it, and can be discarded after we do.

            And so we find many reasons to deny the gamete-dependence claim, and to embrace the idea that you could have been anyone, and would have been someone else if your gametes had never been created or never joined. And so the thought enters our mind: maybe, just maybe, the gamete-dependence claim is actually a more extreme and untenable belief than the belief that as long as any consciousness exists you would necessarily be one of them.

            I think it is. But you may still be skeptical. There is more work to do on it. We have not solved all the problems with the new view. This is just a summary of what is wrong with the gamete-dependence claim, what we have said so far about how to overcome it and what the content of our new belief should be, and therefore how we have come to find it much easier not to believe in the gamete-dependence claim.

            I will enumerate some of these problems in part c and then deal with them when I come to talk about death in section 2. But first, a slight digression, offering another reason to believe as I have argued for so far.

c. Truly Facing The Odds of Existence


            What are the odds that you would have come into existence? If you believe as I’ve argued for, you should now think that, if conscious life exists, then the odds are 100%. What are the odds that conscious life would exist? That’s a whole other question. If we are restricting ourselves just to our present universe, with the physical laws and constants it has and the matter it has, then presumably a complete science could answer such a thing, though such an answer is unimaginably beyond our own abilities at present. (Although, it is a good question whether there are enough potential available computation resources in the universe to figure this anyway.) But perhaps the odds are very good. Maybe the odds of life of any sort never arising in our universe are very small (1000:1) or extremely small (1 billion to 1) or even infinitesimally small (10100 to 1). Or maybe they are about even, 50% chance for, 50% against. Or maybe it is unlikely that life would have ever arose, though it happened that it did. Any of these things could be the case.

            But what if, as many cosmologists now think, our universe is only one of many? Perhaps an infinite number of big bangs and big collapses creating an infinite number of universes in “succession” or “side by side”. If that is the case, then it seems reasonable to conclude that it is 100% certain that life would arise at some point and at some place, and if life, then in some of those cases, conscious life. Which would mean that your existence was certain. Your existence does indeed inhere in the universe, in the totality of everything. You are a necessary part of the universe, not just a random, contingent, accidental part of it. It was certain that you would exist.

            This is a very appealing belief. Emotionally appealing, for sure, which is important, and which I will discuss later. But it is rationally appealing as well. It simplifies everything. It sweeps away all of the troubles I’ve been laboring over in this essay, and many more besides. So I think we should believe it. Count it as just another among many check marks in favor of my view of personal existence.

            And I’ll give you another check mark in favor. Sweep aside everything I’ve told you, everything I’ve argued for, and go back to the simple belief in the gamete-dependence claim you held at the beginning of this essay. What are the odds that you would exist, if the gamete-dependence claim were true?

            We know they would be extremely long. We knew that before this essay, and many of the exercises of this essay have made that vivid. I’ve been troubled by these odds for a long time. Not troubled at how long they are, but just that on some intuitive level, it seems ridiculous to believe in them. Before I came up with the accoutrements and apparatus of this essay, I recall presenting people with a simple argument from incredulity: you can’t really believe in the gamete-dependence claim because the odds are too absurdly long that you would come into existence. I mean really, just absurdly long.

            You have to first appreciate what it really means to not exist. What we mean when we say non-existence. To never exist, now or at any other time in this universe, and in no other universe. To just never ever ever exist. On the gamete-dependence claim, this is what we believe would be the case had that one moment, that one opportunity for the A gametes to be created, passed by without creating them. Or had they been created, and that A sperm lost the race to the ovum against its compatriots. Or had a different ovum been ovulated that month than the A ovum. Even if the A ovum had been ovulated the previous month or the next month, there is nothing that could have been the A sperm during those times to fertilize it (unless the A sperm had been frozen), not even an identical one. And so, had that one tiny (in both the time and space dimensions) window of opportunity passed by without the right things happening, you would not and would never exist. What do we mean by this, not existing, on the gamete-dependence claim? Never mind whether you will continue to exist after you die, just no you to ever even wonder that, and no chance of it at all. (Why do we worry about death so much, if we really believe the odds of our existence were so long? Wanting desperately to not die is like wanting desperately to win the lottery a 2nd time. Do people really believe that a) it was massively contingent that they would come into existence and b) now that they do exist, that existence will or should obtain for all eternity as a soul? Do they not feel doubly bad for all the people for whom existence passed by, never to be retrieved? If existence is really eternal, as a soul, why should there be such a tiny window of opportunity for it to come to be?)

Non-existence is not quite comprehensible. This has been remarked before. It seems comprehensible when we don’t think about it too hard, but digging really deep it then seems to not be so. My own not existing is exactly the same to me as the universe not and never existing. If your A gametes had never been created and never met, it would be just as if the universe had never existed at all, as if there were nothing rather than something, for all the difference it would make to you. This is seriously hard to take. And if we go back to the beginning of the universe and all the different ways things could have gone since then, never mind the different ways things could have gone 100 years ago or yesterday even, the fact is that the odds must be much greater than 1 in 10,000,000,000,000,000,000,000 add zeros ad nauseam, or any absurdly large number you can think of to write down.

And yet here I am.

So yes, I do feel quite incredulous about this.

            Of course, this will get you nowhere with most people who pride themselves on being rational and unsentimental. On strictly logical grounds, the hole in this “argument” from incredulity is manifest. No matter how long the odds are against something, it is still possible. If you find yourself confronted with something that was so extremely unlikely, such as your own existence on the gamete-dependence claim, you cannot retroactively declare that the odds must not have been so long after all. If you try to argue that this violates some intuition you have, some deep feeling in your gut, you will be dismissed as irrational, allowing sentimentality to cloud your judgment. (You just want to exist too much, are too afraid of non-existence, and are not thinking straight, for example.) And rightly so. You have to be able to give reasons for believing things. Incredulity, no matter how true that feeling in your gut that something is wrong seems, is not a good reason in itself, for anyone else at least. To anyone else, you are just one in a range of possible human beings; you are not perceived as a possible personal existence. And so, to anyone else, they can rightly say, well, whatever human beings existed, they could just as easily ask the same question. And yet there is nothing to be amazed about when a new human being comes into existence (these days).

            Of course, my gut feeling of incredulity really came from something I would not clarify to myself for some time afterward, that the trouble with those odds is not that they are so long, but that we believe in them for no reason. We believe in the gamete-dependence claim for no reason. Looking at the odds helps us to see this. So there was a 1 in 10,000,000,000,000,000,000,000 etc. chance of you coming into existence? So what exactly was so special about that one sequence of events and no other? How does that sequence of events connect to your existence? How does it explain your existence? I didn’t have all these words or concepts at first. But the gut feeling of incredulity was definitely a motivator for me to find them.

            Here’s some thought exercises, to see if I can make you feel as incredulous as I do about it.

            Go out and take a walk for a few minutes, in your neighborhood. Get an idea of how much space there is, even in your infinitesimally tiny corner of it. Really do this, don’t just stay inside reading. When all you have is your thoughts and the space between you and the book you are reading occupying your attention, it is easy to underestimate space. So step outside for a few minutes and take a walk. (I actually know no one will do this, so what I’m really asking you to do is to remember this thought next time you go out, and to spend some time contemplating it.)

            In our cultures of sexual taboo what I’m going to ask you to imagine next is easily the most disgusting thing I’ve asked of you yet. Or funny, depending on your temperament.

            Step outside and walk through your neighborhood. Walk for ten minutes or fifteen minutes or so. Up the street, around the corner, up a hill, past a park. Feel the space. Stretch your arms. Touch a tree or a building. Consider going left, and then at the last second go right, leaving all that space to the left behind you.

            After ten or fifteen minutes of this, stop for a second and look around you, holding all the space you can see and all the space you’ve passed through in your mind. Got it?

            Okay, now imagine all of this space filled to the brim with human gametes. Just filled, every nook and cranny, as far as the eye can see (when its empty), with tiny tiny microscopic human sperm and ova. Just absolutely everywhere.

            Now imagine that of all those gametes in all that space you’ve just walked through (which you would obviously not be walking through if it were filled with gametes), in there buried like two needles in a hayplanet, are the A gametes, the A ovum and the A sperm, the two gametes that produced you. They could be anywhere in there. The ovum somewhere near where you started, the sperm somewhere near where you ended. Or they could be closer. Their location relative to all the other gametes is completely random. And of all the gametes in that massive pool of gametes, these two have to join in order for you to come into existence. If they do not, if they die without joining at all, or join with any other gamete at all (assuming you don’t believe in DS), then you will not and never ever ever ever come into existence. What are the chances of that? Because this is the real conceptual space of the odds against you coming into existence.

            I’m just kidding. Of course it isn’t. The space I just described is laughably small. You haven’t even covered much of our own planet by walking through that space, let alone the universe. So you should expand this conceptual space to include the whole earth; nay, the whole solar system; nay, the whole galaxy; nay, the whole universe, really. Well, smaller than the whole universe. There isn’t near enough matter in the universe to fill the universe. So instead, just imagine all the matter in the universe made into human gametes. I don’t know how much space this would fill. These are all the possible gametes that could have existed at the time your A gametes were created. And only one pair could be the A gametes. And they have to meet to produce you. This is the conceptual space of all the possible human gametes that could have come into existence that would not produce you. And yet, of all those possible gametes, the one pair that would produce you did come into existence and did join. Are you feeling incredulous yet?

            We shan’t stop there. All those human gametes filling the universe, they presumably all have different DNA sequences. So we need to multiply the possibilities Vastly beyond even this universe filled with gametes. One possibility for a universe filled with gametes is that they are identical to the A gametes. Another possibility is that they are all identical to the A gametes with one difference (one nucleobase pair difference). Another possibility is that they are all identical to the gametes that produced the person sitting next to you, and another to your sister, or to your brother. Each possible human genome represents one possibility of a universe filled with gametes. So we multiply the number of gametes that would fit into the universe by the number of possible different human DNA sequences. And of all those gametes, only one pair would bring you into existence. In other words, only one pair out of the universe of gametes identical to the A gametes, and no pairs of any of the other universes of gametes. Those are the actual odds, one in that many.

            Kidding, kidding. Those still aren’t the odds. We then have to multiply this by the amount of time the universe has existed, and how many different sets of gametes could have died, and the matter from the dead gametes used to create new gametes, in that stretch of time. This is a vague number, because who can put a number to how long is required for a set of gametes to come into existence, die, and the matter used to create a new gamete? And then of all that time and space, only one pair that come to be at one moment will bring you into existence. No other pair before or after or at the same time, or of any other DNA, could have brought you into existence. If that one pair pops in and out of existence without joining to each other, then you will not and never ever ever exist, in this or any other universe.

It is tempting to solve this problem, the time problem, by saying the following: if gamete pair X would produce you if they were joined, then if instead of joining, gamete pair X were destroyed but the same matter later used to create gamete pair Y of the same configuration (including DNA) as gamete pair X, then gamete pair Y will also produce you. Such a small victory it would be anyway, given the size that remains of the other dimensions. But it is in fact not a victory at all, as it produces the same problem of compossibility as any other deviation from the gamete-dependence claim. Because gamete pair X could produce a human being, and then the matter that was in gamete pair X taken out after that human being exists, and used to create another gamete pair qualitatively identical to the X gametes (whether we call them the Y gametes or not is not important, as the hypothesis is that any such recreated qualitatively identical gametes would produce you). If human being X had not come into existence, then these recreated gametes supposedly would have brought you into existence, but if human being X does come into existence and bring you into existence, those recreated gametes now bring someone else into existence. We have to solve that compossibility if we are to believe this. And if we can solve the problem of compossibility (as we have), there is no further motivation for believing the gamete-dependence claim.

            And the same for another tempting solution: we just say that the DNA is the one essential property after all. Any gametes having the DNA of the A gametes would bring you into existence, never mind the arguments against DNA as an essential property. This would indeed be a big victory if it were at all, because it would cut down the odds to an actual manageable number. The odds of you coming into existence would just be the odds of a particular DNA sequence coming into existence. Long, to be sure, but not incomprehensible or absurd. And we don’t even have to worry about cross-fertilization. Of an all-the-matter-in-the-universe collection of potential gametes identical to the A gametes, every one would produce you, and so it would be certain that you would exist if any of them brought a human being into existence.

            But to accept this, to take this victory in the battle against the absurdity of the odds, is again already to deny what made the gamete-dependence claim appealing in the first place. Because we have again allowed the problem of compossibility to enter in. And we need a solution to it. And once we have a solution to it, of how to conceive of it and how it works in practice, such as split brains/split consciousness, then all the work for denying the gamete-dependence claim has been done, and there is no need to think DNA is essential. Figuring out how to deal with more than one possible physical object bringing you into existence was the hardest part, and conceiving of this was the hardest thing to conceive. So why care about DNA at all after the hardest work has been done, especially when there are the independent arguments against it that I have offered (DNA as mere information, and the DNA sorites)? And so if we let DNA be the only essential property, then there is no reason to have essential properties at all. And we arrive at my conclusion: any pair of gametes could have brought you into existence. Every pair of gametes has equal status as a candidate to bring you into existence, including the pair that actually did.

So we are back to all or nothing. Either deny the gamete-dependence claim entirely, and conclude as I have, or accept it entirely, and all the difficulties with it that I’ve pointed out.

Let’s go back to believing in the gamete-dependence claim, and figuring odds.

All this multiplying may be moot anyway, if the universe is infinite either in size or time. Then there are an infinite number of possible gametes of even a single sequence of DNA. And how can we calculate the odds at all then? Of an infinite number of pairs of gametes, only one will produce you. So the odds are 1 in infinity? Isn’t that the same as impossible? (It probably isn’t, but it sounds nice.) And we come to the problem we are actually looking at, which isn’t odds, but is the fact that there’s no reason for one pair to bring you into existence but not another anyway. Considering an infinite number really makes this stark.

            So this is the real conceptual space of the odds of coming into existence on the gamete dependence claim. One tiny point in space and time of all the points in space and time of the universe, multiplied by all the different possible DNA configurations (which is a vague number, as we would have to stipulate whether to include only DNA that would bring a human being into existence, or any conscious being into existence, or any animal at all, or any organism at all, or any sequence at all, the borders of all of which are vague as well.)[69]

            And here you are now, existing, against those odds.

            Now do you feel incredulous?

            I sure do.


            There is another issue. We feel we must be free. We believe in our bones that we are. Whether we can find a physical account for this supposed free will or not, we believe it. It is essential to the way we go through our life. Thus: we believe that things could have gone differently than they did, at least since human beings with this supposed free will have existed.

            We also believe, on the gamete-dependence claim, that each of us might not have existed. But we don’t think much about the many ways in which that non-existence might have come about. We don’t analyze it, the way I did above. It is just a vague possibility that might have obtained. But—luck of lucks!—it did not. The right things happened and we now exist.

            And now that we exist, we, each of us, can do anything. Anything is possible for us, any decision, any movement through the world. We can go here, or go there, to Italy or Polynesia or Zambia or into a submarine near the bottom of the ocean. And if we have a sexual partner, we can have sex however and whenever we both please. And we can find such a sexual partner out of any of the millions of available people in the world. The possibilities are seemingly endless. Because we, each of us, are free.

            Each of us believes this about ourselves. But to what extent do we believe it about others? More to the point, to what extent do we believe it about our parents, and their parents before them, and their parents before them? If put to us directly, we would answer we believe in it just as much as we do for ourselves. But subconsciously, we deny this.

            When we believe in the gamete-dependence claim, in order to get the benefit of the free will that is so essential to our well-being, yet to avoid the horror of non-existence, or at least the horror of how unlikely our existence actually was, we seem to tacitly, sub-consciously, have two different beliefs about freedom, depending on when we are talking about. In order to go through the world with a relative measure of well-being, we subconsciously discount the freedom that our parents and the people that came before us had. Before us, we tacitly believe, there wasn’t actually that much freedom. Sure, there was some. But not all that much. There was some sense of inevitability about how things happened before we came into existence. Nobody claims this explicitly of course, but this is our tacit belief. And then, after we came into existence, after we become conscious and start thinking for ourselves, total freedom enters the picture. Each of us has billions of options ramifying at each moment. Our parents, well sure they did, but really, the way things went was sort of predictable, wasn’t it, given all the facts at the time? So sure, the odds against us coming into existence were long, but were they really?

            What we really want is determinism before our conception, and freedom after it. We don’t examine it too closely, and this allows us to sort of believe in this illusion. This illusion, which we avoid confronting head on and thus avoid having to criticize and thereby risk losing, is what allows us to go through the world with relative ease. With this tidily tucked away, our only existential worry then is death. We secured existence, and now we have to think about what it means to lose it again.

            Consider again the past, on the gamete-dependence claim. This time the recent past. And a very specific past: just that of your father. Never mind the history of the universe, or the Vast conceptual space of possible gametes. Just consider the day that your father and mother copulated and produced you. There is your father, a few hours before your conception, walking down the proverbial street. One step, next step, next step. Where does the 1,288th step of that walk land? In our actual universe, right there in that spot. But your father could have made a split second decision to place it just one centimeter to left. For any reason at all. He was free, as free as you are. And surely you believe you could do this. Or it could have happened for reasons external to him, just as for you. (A cat could have popped into his peripheral vision.) But lucky for you, it did not. The 1288th step of your father’s on that day landed just where it needed to to bring you into existence. If it had not, that would have changed everything. (Not necessarily, but we’ll just say it would have; there are certainly many such changes that would have.) When your father met up with your mother later that day, and they got romantic and/or frisky, the act would have resulted in a different sperm fertilizing that ovum, if any did at all. And therefore, a different person coming into existence, and you not existing at all, ever, at any other time or place in this or any other universe.

            And how many such tiny decisions were there in your father’s single day? Uncountable. Even for a single day.

            Of course, it is countable, because on that day, it is likely that your father had already produced the sperm that produced you (and your mother had certainly already ovulated the ovum). So the odds are as they are usually calculated, the odds of that one sperm beating out all the others to fertilize the ovum. 1 in 250 million. Actually less, because many of those are unviable. But actually greater, because it was certainly not certain that one sperm would fertilize that ovum at all. But at any rate, the odds look to be not too bad now, in comparison to the other calculations I tried to make.

            But we simply reverse in time a day or two or three or more. Same scenario. Your father is going about his day. He does one particular thing. But he could have done it just slightly differently. Every single thing he does every moment of that day affects which sperm he will produce, and therefore whether or not he produces sperm A (assuming any sense could even be made of identity in these cases, which it cannot). And this is true for every single day of his life before the production of sperm A. And every single day of the life of every person that came before him, and every ancestral organism before them, and every event on earth before that.

            And as a by-product of these attempts at accounting for odds, both in number of possible gametes and number of ways things could have gone differently, the absurdity of the idea that we can assign an identity to gametes at all really becomes vivid. And yet, on the gamete-dependence claim, whether or not you come into existence absolutely depends on this identity. Depends on there being this identity. Depends on this identity being a real thing. Something that we can trace and pick out.

            I will say it again, for the last time, and finally with the amount of force it truly deserves:

            The gamete-dependence claim cannot possibly be true.


So we stop believing in the gamete-dependence claim. This solves all these existential problems. But creates some new ones, both for rationality and for our emotional response. One of the latter has to do with odds again.

            Who you are is just as radically contingent on disbelief in the gamete-dependence claim as whether you exist at all is on the gamete-dependence claim. And by who, I mean what human being. What content you have. What DNA sequence you have.

            Confronting how truly radically contingent it is that you have the DNA sequence you have can be disturbing. Because it is much more radically contingent than any significant life-shaping or identity-shaping (identity in the sense of content) even that has happened since you were born. Whether your parents put you up for adoption, or what town or country they raised you in, or what was their parenting style or philosophy or what was their emotional engagement with you, whether they survived your childhood, or other things such as how you were educated or what religion you had, all these things are deeply important to your identity (in the sense of content), to who you are, to what matters to you in your life. And yet the contingency of these things is a drop of water in all the seas of the world compared to the contingency of what your DNA sequence is.

            And there is more. Who you know is just as radically contingent as that. In other words, which other human beings exist in addition to you is extremely radically contingent.

            Our lives are filled with human beings. They are, for most of us, by far the most important things in our life. They define our life. We have brothers and sisters, nieces and nephews, co-workers, bosses, acquaintances, friends and best friends, social circles, classmates, and all the rest. If we leave personal existence aside and just focus on the “content” of these people, their genetic makeup, and therefore what they look like (most importantly for human beings, their face) and much about their personality, we have to confront the fact that every single person we know is radically, obscenely contingent. Much more contingent than whether or not we got that job, or got accepted to that school, or moved across town when we were 15, or stopped off at the pub last night, all occasions where we tend to meet the people who fill our lives. Much more contingent, in other words, than whether we would even meet these people in cases where they do exist (non-family members), is whether these human beings would have existed at all for us to meet.

            And we know that if these human beings hadn’t existed, we would have met others, and filled our life with them instead. And there is no reason to think that if we hadn’t met them, we would have met the person their parents had in their stead. That we would have met a transworld sibling of them. In some cases we would have, such as when you are placed in alphabetical order in school. In others, this is much less likely, such as at work or your local bar.

Again, I’m not asking whether they would somehow be the “same people” inside. Your friends in this world would still have their personal existence in that other world, but there is no answer to the question of whether they’d be the “same person” as you know in this world just with a different genetic body. Any more than there would be an answer to the question of which person they’d be if their zygote had split and produced twins. So set aside personal existence, and just think about how you experience them, as human beings from the outside. In other words, just their characteristics (content).

            So this is how different our social life could be. It is radically contingent. And radically contingent for each person, multiplied by each person we know. We know this without even thinking about the gamete-dependence claim. The gamete-dependence claim has nothing to do with this. It is just a fact of our life we’ve always known, yet never confront.

            You were walking down the street with your brother, before he had any children. He took that 1,298th step. Here, or 1 cm to the left? That moment determined whether your niece or nephew was the human being that exists now, or whether a completely different human being came to be as their offspring. It was a completely random selection among all the possible genetic combinations he and his partner could have produced. And it was determined by what happened and what he chose to do every moment of every day up until the production of that sperm and his copulation with the mother of your niece or nephew. This is not a metaphysical speculation. This is a simple statistical fact.[70]

            And so too with every other person you know. Your best friend, your life partner.

            And your own children. I do not have children, but I think most people subconsciously assume a certain inevitability about what human beings they sire. That, it was destined. If not 100%, then maybe mostly. Maybe just the gender and general characteristics of each child. But it was not. Any more than it was destined that you would make your cup of tea in exactly the way you just did. Put the teabag in here, or half a centimeter to the left? Steep it for 45 seconds, or 46? Shake it twice, or three times when removing? In relation to your offspring, every one of those motions results in a completely different human being, completely randomly selected from among all the possible combinations of you and your partner’s DNA. The sperm are randomly distributed—there is almost a 50/50 chance as to whether the sperm that would have fused with the ova had one tiny thing been different in the actions of your father would have resulted in a male or female human being. And the configuration of the rest of the DNA was just a completely random assortment of the possibilities your father could have produced, so that there isn’t a gradient of similarity as we move further from the exact set of circumstances that produced you. No, one tiny change it’s a completely different sperm, as different as any sperm could be that was produced by the same person. Same ova, for that month. But though the ova all already exist, which one is ovulated each month likely has a great sensitivity to these minute differences as well, if not as much as sperm production and selection does.

            All this is true whether you believe the gamete-dependence claim or my more radical metaphysics, because we only experience the content of other people, not their “inner existence”, or which inner existence they are. But if we deny the gamete-dependence claim, then, again, this all applies to you yourself. What DNA you ended up as (or with) is as radically contingent as anything else. You could have been anyone, any human being with any sequence of DNA, with the tiniest of tiny differences at any point up until the time you were conceived.

d. Complications

I called the story I told at the beginning of Part IV the minimal conclusion. I call it minimal because I think, with the story spun this way, it is the easiest possible version to believe. That world is very similar to ours, and so it requires little else to imagine besides being another human being. And since all the people are different, we can pick any one to imagine being. There is no principle at all to guide us to one or the other. In truth, of course, nothing hangs on all the details being so similar in the present and the last century and more of history. It just makes the story most vivid, and I had fun telling it that way. And if we then rehearse all the arguments against the gamete-dependence claim, and consider the odds argument as well, we find it pretty easy to believe, and should properly feel compelled to believe it.

But if I had told the story as much more similar to our own world, it would have brought up complications. What if things hadn’t started changing until, say, two months before you were conceived? Your parents would have existed. If they were already together then, then perhaps they still would have conceived a child around when they conceived you. Then you would be strongly tempted to identify yourself as that child. But this would be wrong. In principle you can’t say if you would be that child or any other. But still, we would be drawn toward this conclusion. So this raises a complication, and makes us think too hard about who we would be, and to question the whole premise. So the more different but not-too-different world is easier to believe.

Or I could have made the alternate world much more different. It could be a world with only 100 people left, after some catastrophe. Then we are reminded that, if you have to place yourself as one of those 100 people, then so do all of the other 7 billion people on earth now. That is a big wrench in an easy story. We know how to overcome it, with the idea of splitting and fusing of consciousnesses, but being confronted with it so starkly definitely makes it harder to believe than if we can vaguely imagine a roughly one-to-one matchup of human beings in an alternate world. (That vagueness is essential to our ease of imagining; it was never stipulated that there was exactly the same number of people in this alternate situation anyway.)

And we can make it worse: what if all of these 100 people are 20 or more years older than you actually are right now? Perhaps there was a Children of Men-type catastrophe that made having children impossible. But these people would all be old enough to have been your parents if we consider a variation on that world in which that catastrophe hadn’t happened, and those 100 people had had children. If you look at that slight variation in isolation, the one with children, you might most naturally place yourself as one of their offspring, around your same age, rather than as one of the 100 people of the original world. But then if you look at the original world in isolation, you have to place yourself as one of them. So in one world you are one of the parents of the person you would be in a slight variation of that world. Complications galore.

Or what if all the people who were left were exactly five years younger than your age now? If, in other words, all the people that existed before them had died already. (Catastrophes: such a rich source of puzzles.) Then we simply imagine a slight variation on this world, where all those people hadn’t died. If you place yourself in that slight variation on that world as someone who was your age, then that person would have died by the present in the original world, and you’d have to re-place yourself as someone who already existed when the person you placed yourself as in slight variation had died. Complications galore.

We can see the complications clearly in the most extreme case. There are two people, a man and a woman. You are one of them. They have a child. Then they die, and the child is left alone. If the necessity I’ve argued for is correct, then in a world with two human beings you must be one of them. In a world one human being you must be that human being. So in this scenario, first you are one of the parents, and then you become the child when the parent dies.[71]

And what of the child who comes to be? There were two people, and then three for awhile. If the new person, the child, wasn’t a whole new and separate existence from the adults, what was he or she? It certainly seems that he or she was not a branch of the existence of his or her parents, as would be the case in splitting zygotes or split brains, but an entirely new existence. After all, the parents still exist. They haven’t branched. And how could the split-consciousness solution to compossibility have any relevance here?

Or possibly worst of all: I find I still hold a strong intuition that if the A gametes had come into existence, I would be the resulting person. And with this comes the belief that I will follow them wherever they go, just as I follow my body. If the A gametes had been brought to a spaceship and joined and the resulting person was living out on a distance space station now, I feel that that’s where I would be right now, as sure as if I’d been brought to that space station when I was a newborn, or ten years old, or last year. Or if the A gametes had been frozen for five years, then I’d be wherever that human being is right now, five years younger.[72] I know this goes against other convictions I claim to have, but this contradiction is not problematic in the normal course of things. In the normal course of things, if sperm A does not fertilize an ovum, it will soon die, as will the ovum if it is not fertilized. In my mind, the death of either one of these gametes (not believing in DS) “frees me up” to be another human being, because “I” will not have to be “waiting in the wings” ready to be the resulting person if they are joined, which could happen at any time. But what if sperm A does not die? What if, horror of horrors, it and ovum A are frozen for all of eternity? Will I be “locked” in them forever, and never come into existence again, unless they are destroyed and my existence is then “freed” to go and obtain in another organism? And if I say I will become someone else if they are not joined, then they can just be joined after I become that other human being. Then that human being who came from the A gametes, my gametes with my DNA in the world you and I are in now, will be a different person. I could even meet him someday.

This is another reason that the minimal conclusion is easier to believe than other conclusions. The A gametes of this universe don’t exist anywhere there, and could not exist. Even if identical gametes happened to come into existence from different parents or a different method, they wouldn’t be the A gametes. I’d have no more incentive to identify myself with that human being than any other. But with the A gametes in existence, I still feel compelled to identify my existence with them, wherever they go. This must be wrong, given what else I claim to believe, but I still feel drawn toward it. As surely as I feel drawn toward the belief that I will find myself wherever the human body called Joe Kern goes from here on out, until it dies.

            These situations certainly seem to be a complete breakdown in the idea that the splitting of consciousnesses is a solution to the problem of compossibility. This is why I chose to express the minimal conclusion first. Perhaps now we wish to backtrack and deny even the minimal conclusion. If we do that, then we are back at belief in the gamete-dependence claim, and we have to deny some of my claims and arguments against the gamete-dependence claim. I find I cannot. I will repeat what I promised not to: it is simply impossible for the gamete-dependence claim to be true.[73]  Think just of the minimal conclusion, with the seven billion completely different human beings, and decide for yourself, are you there, or are you not? Do you exist, or do you not exist and never ever ever will under any circumstances? Given everything we have considered, I find I must believe that I would have to be there. But this doesn’t make the above difficulties any easier to take, or comprehend.

So it appears that we do not yet have a complete and satisfactory new view of existence. The final key will be understanding how to view death, which will also help us to understand all these other complications.

  1. The Maximal Conclusion: At Last, We Get To Death


Being brave

Lets no one off the grave

Death is no different whined at than withstood

-Philip Larkin, Aubade


a. New Age Dreams


            The gamete-dependence claim is only about coming into existence. Compared to what follows, its limited scope makes it easy to handle, and easy to dispense with. After all is said and done, it might seem like a small thing to decide that your coming into existence wasn’t dependent on gametes, given all the arguments we have brought to bear against this view. It is a simple, single shift in one concept. But dispensing with it has consequences outside of coming into existence. In particular, it has consequences for how we think about death. These consequences are mostly welcome on an emotional level, but they are harder to grasp, and harder to accept on a rational level.

            I’ve mostly been ignoring the time dimension so far. In my minimal conclusion, I told a story about an alternate history and ended it at the present, and said I would be there right now in that situation, as a different human being, as would you. But of course, if we throw it wide open to any set of gametes being ones that could bring you into existence, then we cannot limit ourselves just to the present, or to gametes that were produced at the same time as the gametes that produced you. Any set of gametes, at any time, are candidates for bringing you into existence. When I asked you to imagine a universe filled with identical gametes coming into and out of existence in succession at every moment, this became obvious, if it wasn’t already. If we deny that just one set of those gametes coming into existence at one moment would bring you into existence, as we clearly should, then not only all the other gametes at that moment, but all the gametes before and after, become candidates to bring you into existence. All the way back to the beginning of the universe, and all the way forward to the end. We can do a simple time sorites on the creation of gametes, just as we did a space sorites, if we need to, but I suspect most people wouldn’t need that to see this point. There just could not be anything special about the time of creation of your gametes, any more than any other feature of gametes, such as location or matter of creation, and therefore there could not be anything special about the time you came into existence. There is no reason to think that the point in or span of time you came into existence is essential to your existence. If it were, we would still have the unanswerable question, why would your existence be “discharged” at this time rather than any other? If your personal existence really were limited in such a way, what could possibly be so special about this time in which you exist, or came into existence? And besides, thinking that time was an essential property would reintroduce problems already solved, such as the problem of fences in indexicality.

            And so this means that you not only would be someone at present in that alternate story, but you would have been someone on January 1st, 1900, when I started the story.

But we don’t need the story anymore, the hypothetical alternate universe. And the start of the story took place in our actual universe anyway. What we should say is that you actually were someone on January 1st, 1900. And that you were someone in 1950 in our universe (and would have been in the alternate universe). And 1800. And 100 years before that. And 1000 years before that. And 10,000 years before that.

            And you will be someone else 100 years from now. And 10,000 years from now. And, if conscious beings still exist, 1 billion years from now.

This is an inevitable consequence of denial of the gamete-dependence claim. And the gamete-dependence claim, I remind you, could not possibly be true. (So says me.)

            So I was someone in the past. I was a lot of people in the past. In fact, I was a lot of beings in the past. Of any organisms that attained a brain complex enough to qualify as a mind, or as conscious, whatever that might mean (I’ll get to that later), I was one of them. And so it will be in the future. After this human being Joe Kern dies, I will be another conscious being.

            We might like to just help ourselves to this conclusion without any further worries. It is quite appealing in most ways, and if it really does follow from denying the gamete-dependence claim, then case closed. But it is also a much more complicated belief than the simple story about coming into existence that I’ve already told. I would be dishonest if I didn’t confront those complications in all their guises head on.

            First, just on the face of it the belief that you will be someone else after you die stretches what we think we should be allowed to believe well beyond breaking, pretty much throws it out the door. We’re talking about a material universe here. There are no souls. There is no “thing” to go from being inside one body to the next. It’s just material, just atoms. This “being” which supposedly travels from body to body is not an energy, not a spirit, not a piece of material. There is no “being” to do the traveling at all. Just completely different and separate organisms. If it is true, it is just a simple fact about the material universe, and specifically about being a conscious being in this universe (and surely in any possible universe). But it is certainly stretching credulity to think that such a thing could be a fact about the universe, let alone a necessary fact. It is nothing at all like other things we take to be facts about the universe, such as the physical constants or laws of nature or mathematics or the evolution towards complexity via natural selection of replicable molecules.

            More seriously, it causes a lot of problems for trying to draw up an account of what it actually means on a practical level. It seems that there must be something that happens when a person dies. If I exist after I die, there must be an account of where “I” go, or at least of going somewhere, even if in principle we can’t say where. But trying to give such a precise account of a single person does nothing to increase the credence of this belief for anyone really committed to a materialist worldview. It makes it seem all the more ridiculous.

            For example, when I die, do I “go” into an already existing human being, like a full grown adult? (Maybe the nearest one?) Or do I go into the next-to-be conceived human being? Or the next-to-be conscious? Or maybe I don’t become just one other person in the next moment in the unidirectional flow of time, but I go back in time and become the very next human being to be conceived after I (the human being Joe Kern) was. (Add as many scare quotes as you like to those sentences.) This would mean personal existence involves becoming every human being, every conscious being actually, that ever existed in “succession” with no regard to time.

            It’s really difficult to see what any of these accounts could have to do with materialism, let alone any kind of serious and rigorous philosophy. These are all fanciful stories, or wishful scenarios. The sort of fantasies that are simply asserted as true in comforting New-Age[74] spiritualties without giving much in the way of reasons or evidence. They gain popularity not because there are good reasons to believe them, but because they make people feel good, or are thought to incline people toward ethical behavior. They are satisfying beliefs.

            And it doesn’t help us much to retreat to the truism I’ve been hammering away at about coming into existence, that it doesn’t make sense even in principle to ask which person I would be. I think this is true. But, while the split consciousness solution to compossibility might help me to understand coming into existence under different circumstances, especially where my A gametes and the human being Joe Kern never exists, it seems harder to implement in understanding death and “what happens” after death.

            But I reiterate to myself my commitment to denying the gamete-dependence claim, and all my reasons for doing so. And so I believe this re-existence or continued existence after death as another human being (or just conscious being) as long as at least one such being exists must be the case, even if I were unable to make sense of it. Even just remaining a bafflement, it would be more appealing on a rational level than the gamete-dependence claim.[75]

Fortunately, I can make some inroads toward making sense of it. Once again, we return to Parfit, this time to one of the very many things I think he got right.

b. Series Persons

            Parfit asks us to imagine another strange case: what if the reality of your life was that every night while you were asleep, your body and brain were destroyed (you were killed) nonviolently and painlessly (instantaneously), and then a new body and brain identical to yours at that point of destruction, with all of your memories of the past and desires and goals and anxieties etc. for the future, was immediately created and woke up that next morning.[76] Parfit calls this a series person, and each instance of the series person is called a day person. Our natural, pre-philosophical reaction is to think that in that situation, one person ceases to exist, and another comes into existence. One person dies, never to exist again, and another person comes into existence.

But now imagine if this was the actual case of your actual life right now, you who are reading this sentence at this very moment, but you didn’t know this was the case. You didn’t know the body you are was created just last night, and would be destroyed tonight. You didn’t know that all the memories you have now of all of your life are actually copies in a new brain and body of the lived experiences and memories of a series of bodies that each existed for one day and were then destroyed. You didn’t know any of this.

It is possible that this actually is the case for you right now reading this. Not technologically possible by a long shot, of course, nor even reasonable that someone or some nefarious group would be carrying this out, but logically possible. You could be a person who was created (by what process no-one knows) in the middle of the night last night, just after another body and brain exactly like yours was destroyed. And whose body will be destroyed tonight, with another body exactly like yours is tonight (with all of the memories etc. you accumulated today) created in your place. Because if there were such a day person in existence right now, it would be someone, someone who could be reading this text right now. Even if there had been thousands of other someones who had been this series person in the past, at this moment, it would be someone. And so it could be you. Or you could be it. These could be the actual circumstances of your existence right now.

So imagine that this whole process had gone on for all this time, all these years, and you didn’t know. None of the bodies and brains before knew, and you don’t know today, right now, that you are just a day person of this series person. And if things kept going as normal, tomorrow that next human being would wake up and live a day, with the memories you accumulated today in his or her mind, not knowing.

But now imagine that, after all these years of this being the case, and you not knowing this was the case and none of the previous bodies knowing this was the case, you find out right now that this is the case, that these are the actual facts of who you are right now. Someone tells you, say, and for whatever reason you believe them completely. So that right now, at this moment, you learn this fact, and you know it as well and certainly as you know anything. You are convinced of it, that it is true.

Does this change the way you view your life? And are you afraid to go to sleep?

At first, it probably would. You would be afraid to go to sleep. The destruction of your body would for you be death, your ceasing to exist. And it is not what you want, to have another body created to live the life you would have. Even though the content of your life would be maintained in that case, that is not the thing you really want. You want to exist, and most definitely do not want to not exist. And you want to be the person with that content. It is not enough that someone else would have it.

But then you think of another thought. You think, wow, what a coincidence that of all the times this series person could have found out that this was the case, he/I found out now, when it was me that existed. This information was imparted to us/me on the one day that I existed! I didn’t exist before this morning and won’t exist tomorrow (all that time before and all the time hence will be just as if nothing existed at all, for as much the existence of the universe during those times will matter to me), but the one day I exist is the day we/I find out about this! If they had waited just one more day to tell this series person, then I would never know about it, since I won’t exist at all tomorrow.

But then you reflect that, if it turned out that they were lying to you, and you really had been the same human body object all this time, then you wouldn’t think it to be such a coincidence at all that they told you today. It would be a ridiculous thought. You would see that this is just a case of being amazed by a simple indexical fact. In other words, you would see that if it was going to happen to you, it had to happen at some time, and so there is nothing more amazing about it happening on this day than any other day. The only way an indexical fact like this begins to seem amazing is when we think our existence is limited to this one case (day) of consciousness and no others. If this one case of consciousness uniquely brought you into existence, where no other would. If you today, over the whole day, is a different category of thing than any other consciousness.

Then you think another thought. You know they are not lying to you. You are a series person. And you reflect that nonetheless the thing you want obtained all that time in the past. You are assured that your memories of existing in the past are correct, as correct as any human memories could be, and you believe this. And so there is nothing you really regret about the past. Sure, when you think about it, you feel bad that it wasn’t actually you who did all of those things, but that you are just one in a series of copies of the series person who did those things. But in pre-reflective reality, you just feel in your bones that the thing you want obtained during all those times in the past, even if you know that the brain that is thinking and feeling this was just created this morning with these memories. And all those times in the past you/that person did not fear ceasing to exist in the middle of the night, and everything has turned out okay in the present, even though you/that person didn’t know it. And so you reflect that the acquisition of this new knowledge should not change your attitude about tonight, should not give you a different attitude about tonight than those people/you had about any other night.

Then you read this essay up to now. And you recall how there is nothing to explain why you came into existence in the first place. Not DNA, not gametes, nor parents, explain this fact. But you know you do exist now. That is unquestionable. The thing you want obtains right now. But why this human body should have brought that about, you realize, has no answer. And being a series person makes this stark. Why should this human body on this day have brought you into existence, rather than one of the thousands of others? Why did all those others bring someone else (many someone elses) into existence? Why was your potential for existence “discharged” finally on this day and no other? And so you meditate on the conclusion in Part I, “how can I know I will cease to exist when this body is destroyed, when I don’t know why this body brought me into existence in the first place?” You take some comfort from this, and are just about convinced that you will wake up in the morning.

But still, night comes and you are afraid to go to sleep. But you put it off as long as possible, and eventually you do go to sleep.

This what I believe about myself: In the actual case, were this to actually happen to me right now, being told or being convinced that I was a day person, I might in fact fear death tonight. In fact, I know I would. But I believe very strongly that I should not. And at any rate I would have to go to sleep at some point, and when I did, and my body was destroyed and a new body created, I believe I would have the subjective experience of waking up the next morning just as I have always done, and it would be “I” in the sense that it would be indistinguishable in any way from what actually happens in our world when I wake up. So even if I went to bed tonight with fear, I would wake up tomorrow. And I would wake up tomorrow with the memory of having feared going to sleep. And then I would see that I still existed, and I would reflect that I’d had nothing to be scared of after all, and this would make me much less fearful of going to sleep the next night, until eventually after a series of these I would forget it was the case at all, and continue living as I always have.

This is what I believe would happen. But I would still be scared of dying tonight, of ceasing to exist, if I were to find out this was the case right now.

If this is hard to believe, consider another way to look at this. Rather than your body being destroyed and a new identical one built every night, imagine it happening every second, through some fantastical process. One body is instantaneously and non-violently destroyed (“dissolution” would probably be the right word) and another is instantaneously created the very next moment, in the space your body was occupying. And someone tells you that this is the case right now. That this is happening every second in the present. In this case, you wouldn’t even have time to hear the whole fact let alone contemplate the horror of it before you the series person had been destroyed and rebuilt several times. By the time you did contemplate the horror of it, you would immediately reflect, well, this doesn’t seem to be too bad. So I’m just a one-second person? It still seems like I’m a continuously existing person, and I guess, when I reflect on the things I’ve learned in the essay “Personal Existence and its Absence”, this is all I really want anyway. For it to seem like I’m a continually existing person.

What is the alternative to this interpretation? That, in the minute or so it would take to convey that fact and for the series-person to really take it in, 60 different people, different existences, had participated in the hearing and understanding of the fact, each one with faux-memories of what had happened up to that point? And what would be the experience of being a one-second person in that case? For you personally, if you could only be one of those one-second people, throughout all of eternity, if you were ever anyone at all? How would you experience existing for only one second, your activity for that one second consisting of one second’s worth of listening and/or contemplation? On the normal belief, it would be the same as you just popping into existence for one second, in the middle of a sentence someone was telling you, and then popping back out, with no other people coming before or after you. (What I mean is, to the person making the explanation, it would involve beginning an explanation to empty space or a wall, and in the middle of it, a person appearing before her eyes for one second and then disappearing, once again leaving behind empty space.) What would the experience of that be? Just existing for one second with a full complement of memories and full consciousness etc.? When we place such a being into the context of a series person, it seems much better to just call it all one person, and assume you, you yourself, would experience the whole thing continuously.

(Studies of the brain and consciousness already show that such things that should be gaps in our experience—eye saccades, for example—are not consciously noticed because the brain composes whole seamless experiences out of gappy input.[77] We simply don’t notice a great many breaks in our “stream” of consciousness already. So, if such instantaneous dissolution and recreation were to somehow occur, experiencing it seamlessly is not so far-fetched. It is basically what we do already.)

Now consider the possibility of a nanosecond person. Or a Planck-time person. And then consider the possibility that, on the most advanced understanding of physics, this series-person scenario could be the correct way to view all of reality, on the level of Planck-times. That everything disappears and reappears every moment. I don’t know if it is. If it isn’t, we can imagine a universe in which the laws of physics were this way. On a macroscopic level it could be identical to ours. And how surprised would you be if it was? And then reflect that this would change nothing at all about how you view yourself.[78]

So I believe this is the fact of existence. There is, in other words, no difference between “me” waking up tomorrow in this body or “another person” waking up tomorrow in a body identical to the one I go to bed with tonight. But, I also know that that wouldn’t stop me from being uneasy if I were to find out right now that this is true. But I think I shouldn’t be uneasy about it. There would be nothing lost for me in this case. I would not lose my personal existence. Nor would I lost my content.

That is the first half of my conclusion, and I’ll mark it off right now as essentially what Parfit believes as well, so I can discuss our differences in a moment. Before I do that, I want to finish describing here what I think is the right view. It is at this point that me and Parfit (may) diverge.

I believe that if I were a day-length series person, I would wake up tomorrow as that person just as I will in reality as we know it now. My personal existence, the thing I want, would remain in the world, continue to obtain. The next point then is easy to see: how does my personal existence continuing to obtain depend on the content of the recreated person being identical? It is clear that it does not at all, and could not.

The most basic way to see the truth of this particular situation would be to resort to the sorites again. We just change one small factor about the human being that wakes up tomorrow. If you would wake up as an identical copy, then why not as an identical copy save for this one tiny difference? Would one tiny difference, say a very small change in a memory or intention, cause that to be a different person and you to cease to exist? Or we can put it in physical terms rather than mind terms: would one difference in a cell, even a neuron, cause that to be a different person and you to not exist? We should answer no.

But the sorites is becoming facile and unsatisfying. It is better not to rely on it. So lets not think of the sorites any longer.

Instead, just think about the content of the belief that you would show up tomorrow if your body were destroyed and another identical one created. On our old belief, we would have thought that only content was preserved in that case. But something was lost, this personal existence. (True, “personal existence” is a concept I’ve only brought out in this essay, but I claim people had it before it was made clear, and they believed this would have been lost in that case.) But on the new belief, personal existence is not lost in this case. It is preserved. Content is preserved, and personal existence is preserved as well. And personal existence is preserved not by some magical or spiritual process, but just by the physical facts. Just by the recreation of the human body.

So now we have the thought, what if the recreation of that human body was not a copy at all, but an entirely different human body? A random collection of characteristics, say, selected from among all the possible features of human beings. What I mean is, you go to sleep tonight, and your body is destroyed, and immediately a new body is created in the space your body occupied just the moment before. And this new body is completely different to your old body, randomly so. The question then is, if the first scenario of an exact copy preserved your personal existence, why should this scenario not also preserve your personal existence? What would prevent it from doing so?

I’ve hashed over this many times already: what is the connection between content and personal existence? There is none. But we need not rely on the details of this old argument. We can simply see now that the content being identical tomorrow is not the thing that “carries” your personal existence forward. So, if you have been convinced that you could be a series person of any time length (day person, one-second person, nanosecond person, etc.), that a series person would carry your personal existence forward, then if your body were destroyed tonight and a new, completely different person created in that same space, you should just as much believe that your personal existence would obtain in that human being, just as it would in an exact copy of you.

This seems very strange, until you think about what you already believe. As I said, you already believe that if you had gotten a new job in a new city last year, you would be there now, doing that job. And so you already believe that if the newborn you had been adopted by parents in a distant land, you would be there now, living that life. You believe, in other words, that your personal existence would obtain in that human being, even though that human being would be very different in content. You already believe in this idea, that your personal existence can obtain in a human being that is very different in content. So this idea that your personal existence might obtain in a very different human being created in the middle of the night tonight is really not so strange. It should be easy to imagine being that person, as easy as to imagine a different life for the human body you are now. It is true, the DNA is different in this case, and that is a big difference, but DNA is just content just as experience is. If you try, you can imagine feeling, from the inside as it were, that different DNA, being a body made from the instructions of that different DNA, just as easily as you can imagine feeling having had totally different life experiences, such as growing up on a distant island living off the land, with the same body, the same DNA, you have now. So this is not as radical a step as it at first seems.

So then the next step is to realize that this new human body, whether identical to yours now or completely different, need not occupy the same space as yours is occupying. There is nothing essential to your personal existence about the space your human body occupies. So if your clone is created on your sofa in the other room, instead of in the space your body occupied a moment before, then you will wake up as the clone. And the same is true as for the completely different person, if that were created instead.

And then the next step, of course, is to see that two human beings could be created, if the space they occupy doesn’t matter anyway. Two identical human beings. Or two randomly different human beings. In the past, we would have the problem of deciding which human being you would be. This would have rendered this whole line of reasoning untenable. But now we can conceive of it, just the same way we conceived of identical twins coming into existence. You would be one of the two people. There is just in principle no answer to the question of which one you would be. But your personal existence would obtain.

And the next step is to see that there is nothing important about them being created within the rooms of your home. They could be created next door, or across town, or across the world. And there is no limit to the number that could be created. There could be a thousand created all over the world.

The final step is to ask, is there anything hanging on the fact that these new human beings are newly created at that moment at all? Not if we still follow the series-person reasoning that got us this far. Remember that we are postulating that the newly created people that you could become are created with a full store of memories and everything just as if they had lived a full life up to that point. So at the moment you “become” that person, there is no physical difference between him or her and a human being that actually did live a full life. So what factor exists to prevent you from becoming a human being that already existed? I say there is none.

I can think of one objection to this final move. It is not really an argument per se, but more of a knee-jerk reaction. This is that there is already a person “occupying” that already existing human being, and so you cannot become that person. In contrast, the newly created human being needs, in addition to being created, a person to occupy it, so “you” could fill that “void”. This is tempting, but of course it is just a soul view, the idea that a the physical body of a human being needs something above and beyond just the organization of matter that makes it up in order to be conscious or alive or a person or whatever. But I believe this is not so. And if there is nothing more to a human being than the material constitution of its body, then there is no gap that is or is not filled for “who” that person is. If a human being shaped piece of matter comes into existence it automatically becomes someone. This may seem to be in conflict with the view I’m advocating, but I think it is not. I hope the reasons why will be clearer by the end of the essay.

One point I can make now is to remind you that in the case of fusion we had no trouble (or I think should have had no trouble at least) imagining two people becoming one. This is also what we imagine when we imagine who the resulting person would be if the zygote of identical twins hadn’t split, or if two people who existed for a time each with one brain hemisphere of a prior singleton were rejoined. This gets us part of the way to believing that if you could become a newly created person, then you could become an existing person. (I’m tempted to use scare quotes on “become” here, but am resisting.)

What all of this means, if we believe it, is that if you were to die today, you should imagine that you will become another human being. Which human being? I return to the repeated refrain: there is no answer to that question, even in principle. And in this case, as in the case of coming into existence, there is no restriction on which human beings should be included in the set of possibilities. This is in contrast to the cases of the split zygote or split brain, where we limited ourselves to those who were physically continuous with the original singleton. But now the field of possibility has been thrown wide open. Any human being is within the set. We can’t even say whether it will be a full-grown human being already in existence, or a human being coming into its first consciousness, or a human being just being conceived, or, perhaps, just a potentiality “inhering” in a gamete or pair of gametes.

            I think this will seem quite literally unbelievable to a great many people. Many will think our conclusions have gotten far too radical, far too quickly. That this argument has really gone off the rails altogether now, if this is where it ends up. Perhaps you are having a very strong inclination right now to just scrap this chain of reasoning (or perhaps to bury it, out of sight out of mind, if one doesn’t feel it can be denied) as a failed experiment and retreat to some simpler belief. I can imagine that even the gamete-dependence claim, problematic though it may be, will seem easier to believe than this to a great many people. Surely the gamete-dependence claim has fewer costs than this?

            That is a point worth debating. I welcome your case. But let me state this supposedly extravagant belief in simpler terms to see if it can be made more credible for the time being:

At any given time, if there is conscious life anywhere, you will be one of them


This is, to be sure, still a radical belief, some might still call it extravagant. But perhaps it sounds less extravagant than the belief I just built up to about what happens to you after death? I think it does. It is in essence just the belief I started Part IV out with, that if the world had gone differently and there were all different human beings on the earth right now, you would still be one of them. That still seems to me much more reasonable than the gamete-dependence claim. The above statement just adds one more factor, time. I am simply claiming that, if the conclusion holds that right now you would be someone if all different human beings existed, then this necessarily holds for any time. There is nothing special about now that makes it essential to your existence. There is no time-essentialism to your existence.

And if you will exist whenever there is conscious life, then we need some way of thinking about what happens when you die. And this is exactly what my argument about series persons and becoming any other human being gives us, extravagant and unbelievable though it may seem. It is, as far as I can see, an inevitable consequence of the denial of the gamete-dependence claim. You will exist at any time there is conscious life. Therefore, you will exist after your human body dies. Not as a spirit, but as another person. But as who? There is no answer to that question. It is, to coin a term, a sort of materialist reincarnation. No souls jump from body to body. It is just the nature of the purely physical universe and of the experience of existence, or of what the referent of the term existence is.

What I am proposing then is reincarnation with no mechanism. It just is. And I agree, it sound implausible on the face of it. I have a hard time wrapping my head around it myself, a hard time really believing it. But I have a diagnosis for myself: I think I must have a wrong idea in my bones of what personal existence is. I think I have argued rationally to the right idea here, but still, buried deep in my subconscious, the wrong idea remains. Where it came from, I can’t be sure. Perhaps it was culturally instilled by my Christian upbringing and the notion imbibed early on that I am a soul and therefore that a soul would be necessary for this or any sort of survival of death. Or perhaps there is something instilled in humans by evolution that makes a soul seem necessary for any sort of survival.[79] But when I’m not thinking of the arguments I’ve laid out in this essay, this pre-reflective belief holds sway and makes my conclusion here, without the careful arguments forefront in my mind, seem ridiculous, impossible. It is emotionally appealing, to be sure, but it doesn’t seem rationally tenable, to my unreflective mind. Only desirable. Often I just let the desire hold sway and accept that the reasoning must be correct in a happy-go-lucky way. But in my more skeptical moments, I switch, and wonder how it could possibly be true. But then I go back to my arguments, and I again think it must be.

This at least is my process, recurring over and over. (And is this conclusion really desirable? I’ll talk about that a little later.) The more I go over it though, the more convinced I become of the truth of this materialist reincarnation, and the less sway my pre-reflective gut reaction has. And therefore the more I become convinced that I’m conceiving of my personal existence incorrectly. I’ll try to make a little more sense of this in a later section.

My statement of this new view is almost complete, but not quite totally. The final statements I have to make about this new belief are even more “out there” than what I concluded with in this section though, so I’d like to take a slight detour to consider another point, which I think might help keep us grounded.

c. Isn’t This Belief The Same as The No Self View?


            I wondered above whether the denial of the gamete-dependence claim might have already existed in philosophical views held by others. In later sections, after I’ve sketched out the final aspect of my view below, I’ll compare it with those of the specific philosophers David K. Lewis and Daniel Dennett, and will also, of course, give some comments on how I think Parfit’s views compare to my own. Here I will just take up what might be a broad criticism of the conclusion I’ve reached.

Let me briefly substitute the more common term, “self”, for personal existence or “I exist”. What I’ve done in this essay is abstracted the notion of self to such an extent now that “your” self becomes the exact same self as all the others that have ever or will ever exist. This condition is what is needed to make indexicality the correct explanation for why you exist. Your self needs to become the same thing as all selves, literally the same, not just a token of a type. Or, we can just remove the word “indexicality” and say the same thing: this condition is what is needed to explain why your self exists, rather than not. Or, add in the word evolution: this condition is what is needed in order for evolution to explain why your self exists. (Or, substitute the word “consciousness”, which I will discuss later.) In all these cases, the only way to explain why your self exists rather than not (on any version of that question, any place in the hierarchy from Part I), we simply have to believe that your self would exist as long as consciousness exists. Wherever there are persons, you will be one of them.

This is the objection: Can this belief really mean anything? If this is the true nature of the self, then wouldn’t it be just as accurate to say that it doesn’t exist at all, as a great many people have been maintaining already for quite some time? This is the “no self” or “I don’t exist” view. If yes, then my view isn’t really new at all. It’s just a new way of saying an old view, and (some might say) a way that makes no difference.

            I can almost accept this if you want to say this. In fact, I once was willing to concede it outright. Recall that before I had any of the ideas beyond Part I, I was resting on the mysterian conclusion of “how can I know I will cease to exist when I die if I don’t know what brought me into existence in the first place?” This included in it a prefiguring of the oneness of all personal existences I’ve argued for above, but in this case it was a more mystical notion, like some sort of disembodied universal soul, or a god that we all were or would eventually become. My formulation was something like: there could only be one existence, and we all shared in it. When I had found this conclusion and felt satisfied in it for a time, I also had the vaguely conceived idea that “perhaps saying I don’t exist is exactly the same as saying I exist necessarily/as everyone”. After all, both in their own way remove the need to talk about a self, or personal existence, and leave just content as the only real object of discussion.

            But now that I’m on solid materialist ground and have a clear notion of what I think personal existence is and what this oneness and supposed materialist reincarnation are, I think the idea that my view and the no self view are the same is less plausible. I think, in order to really believe that my belief is the same as the belief in no self, you have to believe the following: your next moment is exactly the same as death. If there is no sense to be made of a self or of personal existence, if they are truly not things at all, then the death of a human being is no different than the next moment of the life of a human being. This is because there is nothing that persists from one moment to another in the life of a human being, because content changes moment to moment in the life of a human being. Or, more esoterically, on the indexical view, there is nothing that can be consistent within a single life that is not consistent—the exact same thing—within all other lives as well. We cannot demarcate one thing persisting in a single life and ending with that life, if we deny the self, or personal existence. The indexical view breaks down if we try that.

            So on the no self view, the death of a human being is the same as the continued life of a human being, save for changes in content; you will note that this is exactly the same conclusion I’ve come to, except that, inasmuch as I affirm that there is something that persists moment to moment in the life of a human being, and persists 100% through the normal changes of that human being, that being the thing you want when you say “I exist”, then I affirm that it must persist as long as any conscious organisms or other such things exist at all. In other words, it—the exact same thing, not just another token of the type—persists after death, in other conscious organisms and other such things. Or, to use the language of origins, it—that thing itself, not a token of a type—shows up wherever conscious organisms and other such things show up.

            So either it is no thing at all, and content is the only thing that changes moment to moment, or it is a thing and remains the same thing always, and therefore content is the only thing that changes moment to moment. There is no in between. If you want to take this as a difference that makes no difference, that is fine, and if you want to continue to insist that you don’t exist, that is fine as well. Just don’t believe you will lose something in death besides content. And don’t believe in the gamete-dependence claim either. Because the gamete-dependence claim adds a self or personal existence back in.

            But I think many people who claim they believe in no self surreptitiously do believe they will lose something in death besides content, something that they have maintained all along while alive besides content, even if they refuse to name it. And many of these people also believe in the gamete-dependence claim, that they would not exist if their parents had never met/gametes had never joined etc., in a different way than they supposedly do not exist now. They proclaim with their words that there is no self, no such thing as what I’ve called personal existence, but some essential parts of their philosophizing or worldview center around this surreptitious belief that there is. It remains hidden because they never state it explicitly, but it is nonetheless a premise of their beliefs. It is as though they are saying:

There is no self. And you lose it when you die.


There is no self. And a unique one came into existence when you were born (conceived, etc).

(Remember that I am using the word “self” here as a translation of my term “personal existence”.)

            The point about origins is important, because some might claim that there is no self but there is still a difference with death, namely how drastic the change is. Regular changes within a life are incremental and connected. So this is why the next moment in a person’s life is not the same as death. The incremental change gives the appearance of a persistent self. But this argument cannot be used to explain the origin of a person, on the gamete-dependence claim. What gives “the appearance” of the creation of one self rather than another, as was clarified by PD? The term “appearance” loses its meaning here.

            Recall what Jim Stone said, which I quoted in Part II. First, he says “To put the matter paradoxically, we need to face the fact that we don’t exist. There is simply nothing in nature for us to be.” Then a little later he says,

[I]f we exist at all we come and go in a moment…I suspect that this is the truth about us and that it is the inevitable consequence of science and empiricism, but how one comes to live with the truth I don’t know.

The question I would like to put to him is, why would coming to decide he doesn’t exist, or exists only for a moment, change anything for him? It changes nothing about his life to switch from one belief to the other. It just means he has one less thing to lose in death. He has no existence to lose, so he will not lose it. He will only lose his content. But he probably would have believed he would lose his content anyway even without the belief that he didn’t exist. Claiming to believe the words “I don’t exist” changes nothing about his life, because it changes nothing about his actual beliefs of his life. He still believes, deep inside, that the thing he wants obtains now and will continue to obtain through the life of his body, whether he puts words to it or not.

            If Stone were to disagree with this assessment, I’d be curious to know the answer to this question (I don’t know if he is still alive, so this may be rhetorical): what did you want out of existence that you’re not getting without it, that makes you depressed about the fact that you don’t have it? What disappeared when you decided you didn’t have it?

I think Stone only finds this hard to live with because he does actually believe he exists, and has existed since the start of his human body, and will exist until he dies. If he didn’t, he’d have nothing to be depressed about, because there would be nothing to be lost, either in death or from moment to moment.

I’ll say more in a similar vein to this topic in the sections on Lewis, Dennett and Parfit. My assessment of the no self view is a general consideration that applies to in some ways to all of their own specific views as well.

There is another way to put this objection. Some might affirm my argument, but say that the abrupt cessation of all their content in death, and the “materialist reincarnation” as another human (or otherwise) being with completely different content, is just as good as, or the same as, not existing again. That this sort of re-existing is no good to them at all. And that therefore it is better, correct, to say that they will not exist again. My argument, though affirmed, has not changed their beliefs in any way.

But this belief is the belief that your existence is only content. If your content ceases to exist, then you cease to exist. And if you believe your existence is only content—that your existence right now just is the existence of the content of your life right now, and that there is nothing more to existence—then you must believe that, had the life of the human being you are right now gone very differently from birth, then you would not exist, because the content of that human being would be very different. And you must believe that this “not existing” is you not existing in exactly the same way that your gametes never being created or never joining, but rather other gametes joining, is you not existing. Because if you believe it is not existing in any way differently, then that is adding something to existence besides content. Thus, your belief that your existence just is the existence of your content makes an exact equivalence between these two types of not existing. And this equivalence is all that I want. It’s all that I need to make my belief correct. Because the former case of non-existence—the human being I call me right now having had a different life—is the same as existence to me, and common sense and most people’s beliefs affirm this. Are you ready to deny that you would exist had your life gone differently from birth? This is the cost of your belief that content is all there is to your existence, and that therefore that this supposed re-existence with all new content is not you yourself existing at all. But if you do believe that you would still exist had the human being you call yourself right now had a different life, then on the original equivalence, you must believe that you would exist as a human being from a different set of gametes, i.e., deny the gamete-dependence claim. And this leads inevitably to belief in materialist reincarnation, crazy as it might sound. So my new view does make a difference.

d. Is The New Age Dream The Correct Belief After All?

So now we can face the question, if we want to, what really happens to you when you die, if you don’t cease to exist? (This question is in some senses optional, for reasons I will come to.) If you are “here” in the body you’re in now, from moment to moment, which I think is a solid intuition that should be respected, then where do you go the very next moment after death? In some ways I’m breaking my rule here by asking this. I perhaps should just stick with what I’ve already said, that in principle there is no answer to who you become, and by extension “what happens”, and leave it at that. At this point, the internal view or subjective view I’ve been adhering to/insisting on all along may no longer be relevant, or may really not make any true philosophical difference. And as you will see, some of the speculating I do in this section does sound pretty goofy, taken just on its own. But I’ve given it a lot of thought anyway, not necessarily on purpose, and I do have some ideas about what is the best way to look at this. And in fact, the way we look at the following situation may have some repercussions, for example for morality, so it might matter which view we choose anyway.

            So how, specifically, should we view this so-called materialist reincarnation? What should you think will happen when you die? You will become someone else. But what other people are in the category of beings you might become? The way I see it, we have two choices. We can either demand adherence to time’s arrow, and say you can only become a person in the next succession of time after you die, or we can plead the unreality of time, and say that time has nothing to do with who you become next. In this latter view then, you could become anyone throughout history.

            As I said, I have always known that both of these views, or any case of trying to nail down exactly “who” you become on the belief in materialist reincarnation, will sound unserious, airy-headed. Pleasant fictions of New-Age dreams. But initially I thought that respecting time’s arrow sounded less unserious and more plausible. It is after all the thing that follows most simply and directly from my last argument, the series person. If your body is destroyed, you will become someone else at the next instant, with no answer to the question of who it would be. I believe that that conclusion is on pretty firm foundation.

            But this view causes some problems, or at least raises some questions that it seems like we should have answers to, but probably could not possibly have answers to. For example, let’s take up this question first: if we insist, contra what I said above, that you have to jump to the beginning of another human being’s life, rather than in the middle, we might wonder whether you “jump to”, say, the next person being conceived, or the next person having their first consciousness, as in the memory I described before of grabbing the toy from the other kid when I was two. This, to me, has always seemed to be when I really started to “exist”. I have no memory of being a baby before that, so it seems just like I didn’t exist. This is probably well enough for our everyday usage, but it breaks down here if we try to come up with a serious account of this materialist reincarnation I’m arguing for. It is just arbitrary to say that you immediately “jump to” someone having their first moment of consciousness. (Again, I’ll talk about the status of this supposed first moment later, when I talk about consciousness itself below.)

            So it’s better to say that you become the next in line conceptus (zygote). Or is it? There is no brain in a zygote, not even a hint of one. How could that “be” you in any way shape or form? And if we are inclined to believe we “jump to” an object like that, in other words, that we should trace our own existence through space and time from that object, then what of the gametes? Our original intuition, the gamete-dependence claim, was to trace a personal existence from those gametes. If we instead choose to start at the zygote, does that mean that the A gametes wouldn’t have brought you into existence if they’d be joined earlier or later, but instead someone else (someone who had died just before their joining), and that you would be a different human being right now (a human being created from gametes that join just after your death)? So maybe instead you, or your potentiality, does jump to gametes after all.

            Or maybe it’s not both gametes. Maybe only the ovum. Maybe you “jump to” an ovum, and just wait around for a sperm to fertilize you and find out what the other half of your genetic profile is going to be. But even this is bothersome, for a number of reasons. First, an ovum is created decades before it ever is fertilized. It was created when your mother was a fetus. So, if you jump to an ovum, do you just sit in there all those decades, on the off chance that you’ll be fertilized and finally get to grow a brain and be somebody? That’s unpleasant. And if it was random which ovum you jumped into, then the odds of you being fertilized are exceedingly low. One or two or three in 300,000. Even the odds of you being ovulated at all, and not being fertilized but rather being flushed out and dying are quite low.

            This brings up an intriguing point and disturbing thought. (Perhaps you find imagining being a menstruated ovum disturbing already, but that is only some biological squickiness that perhaps we should get over.) I actually still have the strong intuition that, despite the fact that the A gametes weren’t essential to my existence, in other words that I could have existed without them, that if they had come into existence and joined I would nonetheless still right now be wherever the result of those gametes joining was, no matter where or when. So, if they had been frozen and brought out onto a space station somewhere, and then joined five years later and the resulting person were alive right now, I would be there right now, five years younger than I am. I know professing to believe this sounds like a retraction of everything I’ve said, but in the end it is not, which I will explain next when I get to what I think is the correct view. But for now, just think of the consequences of denying this claim, that you would be wherever your gametes had been taken. I find it still an unassailable fact (or intuition, if you prefer) that if I had gone to grab a bite to eat at the restaurant across the street fifteen minutes ago instead of staying here writing, then I would be there right now, eating. I would be there, right now. No question about it. So I believe that my existence is currently following this body around wherever it goes. Therefore, I have to trace my existence as being in this body whenever it existed, and wherever it went or could have gone. And I have to trace it all the way back to the start. What is the start of this body? The zygote? I pointed out the problem with that above. It seems we have to believe either in both gametes, or in the ovum. Just the ovum seems like the more appealing candidate to me, being that it is the body, and we are tracing a body, but in either case there are problems. Similarly to what happens naturally to ova, what if both your gametes had been frozen, as is done these days with modern technology. Are you “locked in” there until they are either unfrozen and joined, or die? Seems arbitrary, number one. But number two, there is this horror: what if they were frozen for all of eternity? Would you be locked in there for all of eternity? There you were, all set to live a succession of lives for millions of years, just materially reincarnating from one to the next, but whoops, you jumped to a pair of gametes that were frozen, and now you are stuck there, not existing. What a tragedy. Now the rest of the universe will go for as long as it does without you in it. It was just your bad luck to jump into a pair of gametes that were frozen and never died. If only they had died! The death of those gametes would have “freed you up” to jump into another pair of gametes, or another organism!

            None of this seems even remotely sensible. I’m not even getting into every problem with this view. There are so many more. And it doesn’t respect the intuitions we’ve worked hard at arriving at or of preserving in this essay even. (Just think of split zygotes or split consciousness.) So we push it forward, and say you come into existence from the first inkling of a brain after all. Or from when there is enough of a brain to be somebody. Or the first memory. But of course, all of these are arbitrary, with vague boundaries. But, if we insist on sticking with the succession of time, that you can only become someone existing in the next moment after your death, and not anyone at any time, then one of them must be true, no? Yet, none of them are appealing.

            And there is another point: if we therefore deny that we must jump to some sort of origin or beginning but still insist on respecting the arrow of time, and therefore say as I did before that there is no reason you couldn’t jump into an already existing person with some years behind him or her, this gives us a loophole out of the arrow of time anyway. If you become someone when they are 30 years old, what is the status of all the time they lived before that to you? It’s just like time that you lived anyway. It is identical in status to your personal existence as the status to your personal existence of the time you have already lived is to you right now: once you “jump to” that human being, the thing you want obtained during all that time in that new human being, all 30 years of it, just like it did for the human being you are right now. In other words, it is your time, just as much as, and in the same way as, all the time lived by the human being you call yourself now is yours. In other words, you lived it. In other words, if you were to die right now and “jump” into the body of a 30-old person, then there is no difference between you having lived all of those 30 years up to that point and you having not lived them. The thing you want obtained in that 30-year old person during all the life of that human being, all 30 years or so of it.

            So we should reject the insistence on sticking to time’s arrow. Everything I said above before the last paragraph sounds ridiculous. The trouble with trying to make sense of materialist reincarnation while respecting the arrow of time is that forces you to really reify your single personal existence beyond credulity. And this trouble arises because we are trying to put constraints on it—that it must respect time’s arrow and therefore be only one human being at any given time—that force us to make it something too specific, with too many identifying characteristics. Instead, we should accept the broadest possible type of materialist reincarnation. I think it should be something like this:

You are/have been/will be every conscious being the universe has ever brought or will ever bring into existence.

            But we cannot understand the idea of being multiple people all at once. Of actually right now being all the people who exist right now. Each of us is only one person. So we need a crutch to help us understand this, a crutch that relies on our experience of time, even if it is to help us understand a phenomenon that should be thought of as out of time. So to aid in understanding the above statement, we can append “in succession” to the end of it. By this I mean, what you can imagine, if you must imagine something, is that, when you die, you “go back” and become the very next person to come into existence after you came into existence. (Still a minor vestige of the respect for time’s arrow.) And here we see one advantage already: on this belief, we don’t need any account or definition of what time in the development of an organism “coming into existence” occurs. It all works out the same no matter what supposed origin point you choose.

So in this way, you “eventually” exist as all conscious life. To be sure, it takes a long time, as it were. Consider that, if you were to live just one year in the life of every human being alive right now, it would take longer than the age of the earth. To make a tangential empathic and ego-deflating point: that’s a lot of experiencing being done, that is almost entirely inaccessible to you. And each experiencer is exactly equal in importance to yours. Just think about that. And that’s just one year at one point in time. To live two years in the life of every human being alive right now would take longer than the universe has existed, which is 13.8 billion years. And if you were to live the entire life of every human being that ever existed, estimated to be 100 billion people, it would take several trillion years, or the age of the universe 200-300 times over.[80]

And there is no reason to stop just at humans. The vagueness in the notion of when the first human being came into existence, and therefore where that number 100 billion comes from, makes this clear. We should also consider that animals, at least all “conscious” animals, whatever that means, are included in this succession, this journey we are all taking. We, of course, is the wrong term now. There is only one of us. I am we and you are we together.

I think this view has the highest problems solved to problems created ratio of any theory of existence that I know. It should not be as surprising as it is either. There is an embedded prejudice between the choice of being only single people in the succession of time, or just throwing your hands up and saying to hell with it, we’re all everyone. Often, when faced with such choices, the most extreme is the preferable to any compromise position. Just give in to throwing wide open every parameter you possibly can. This is, it seems to me, the principle behind whatever success David K. Lewis’s argument for believing in his plurality of worlds enjoys. Any compromise requires lines in the sand, which when analyzed will come out quite arbitrary or otherwise leave the theory incomplete. We saw this in the gamete sorites. The compromise position that you could have been the result of some other numerically distinct sets of gametes but not others, requires more work and argument than the position that you could have/would have been any other set, including at any time, because you have to delineate the difference between the two categories. So too here. To demand adherence to the arrow of time requires that you be just one person at one time, meaning you “become” just one person at a time. There would still be billions of people you would never be. It is easier, cleaner, to just include all people always within the category of people you will be. It solves all of these problems.

And all of the other problems as well. The perfect doppelgänger ends up not being a challenge to materialism. It turns out that there are no perfect doppelgängers after all. You would be person B, because you are/will be everyone. And so the intuition from TMT is correct. We should believe in transworld material transmigration, though it is subsumed by the concept of materialist reincarnation, so we can discard the term (I say with both sadness and relief). And the problem of the continued existence of person A on the ship in TMT is no longer a problem, since now you can just say you would be both of them.

And there is no mystery to whether your mother’s perfect doppelgänger would give birth to you. She would. (This is still possibly my favorite single puzzle to come from this work. Without my new view, I see no solution to it at all, and no possibility of denying its validity.) And frozen gametes for all of eternity? No problem. You are not stuck in there. No one is. You are living a whole life as someone else at that time—all the other lives in fact. And if they are unfrozen while you are living another life? No problem, you just live the life of that unfrozen gamete person “later”. You live all the lives. I do too. We are the same personal existence. Not just the same type. We are the same one. The same token. There is only one token of personal existence.

So I say you are/have been/will be everyone. But this imagining of it as “in succession” is a crutch, probably. We should take the verb tense to be an illusion of some sort. It should be dispensed with, but unfortunately English doesn’t allow that. (Unless “you be everyone” conveys it, but I’m not sure it does.) I don’t have a philosophy of time to offer you to explain this, but both modern physics and modern philosophy have much to say about how time can’t be what we think it is, but is only a thing that seems a certain way to each of us as individual organisms and to humanity as a whole, for a multitude of reasons. But we could just as easily say, you are everyone right now, rather than you will be or have been everyone in succession. I can’t make any sense of this, and so I too rely on the crutch, but it may be a more correct way to say it.

But I am sure that none of this will be easy to swallow for anyone who fancies themselves a sober-minded or rigorous thinker. I wouldn’t expect it to be. Confronted with the sorts of answers that come when you ask “what happens next” after death, you may just wish to refuse to answer. I can respect this. Or you may wish to retreat from the internal view altogether, to say that it is somehow an error. I don’t think this is possible. I think we can only ignore it, but not make it disappear, not make a non-thing.

            So that is it. That is essentially the completion of my argument on personal existence, from the internal point of view at least. This is how I think you should view your own existence, your life and your death.

            But I hasten to add: I do not consider this a completed work yet. It is a draft, and I welcome comments and criticisms from all quarters. In particular, the likelihood of error is quite high for some of my attempts to understand and comment on the contemporary philosophy. At the time of this writing I’ve never been mentored in this field (never done any graduate work or even undergraduate work in philosophy), so there is undoubtedly some lacking in my attempts.

The argument can be broadly divided into two parts: the statement of the problem in Part I, and the solution I’ve offered to this problem in Parts III and IV. You may find my solution far too wild to accept. But rejecting the solution on whatever grounds doesn’t necessarily demonstrate that there is no problem. I feel I have built the argument up in a hierarchical manner, from least controversial conclusions to most. So if I lost you somewhere in my argument, I’d like to know at what point I lost you. Was it at materialist reincarnation? Or that you would definitely be someone else had the world gone differently? Or that we can learn something from the sorites? Or just that there is a problem with the gamete-dependence claim? Or perhaps I lost you at the very start, with my demonstration that existence can be conceptually separated from content. In other words, with the perfect doppelgänger thought experiment. If I lost you there, we may never see eye to eye. We may try to discuss existence together, even be cordial about it, but we may be having two different conversations, each of us changing the subject back to our own topic when it is our turn to speak.

            But that is no great tragedy. A great many questions in philosophy are optional, and I consider this to be one of them. (It is not an emergency, like climate change or the oppression and invisibility of some groups of people.) I look forward to the discussions on the ideas I’ve presented here, whatever form they may take.

            In the next section I want to write on the consequences of my theory, if it were really true. There are a great many, and I’m quite eager to explore them all at length. I’ve found that adopting my view has really transformed my attitudes in many profound ways, especially in finding meaning and contentment with my life, annihilating the pernicious sides of my ego, and greatly expanding the scope of my self-interest to include everyone and everything. I haven’t yet written my thoughts on these things fully in this draft though. For the time being, I offer instead just some main idea statements and sketches of some themes.

Part V: Some Thoughts On Life The Universe And Everything

            Makes Rawls’ original position not just a thought experiment, but actual reality.


            Harmonizes two concepts in Buddhism that seem contradictory: no self and reincarnation. I suspect the Buddhist philosophers who came up with these concepts were operating from an intuitive sense of the truth of what I have tried to reach here analytically. They just saw intuitively that it made no sense to think of your existence as having come into being sui generis at some moment in time due the creation of some particular organism. It seems to me that my view is the truth of what the content of the no self view has been all along.


Materialist reincarnation means you’re going to be reincarnated whether you like it or not, whether you’re good to other people or not, and whether you make the world better or worse. And being good doesn’t ensure you are only reincarnated as other good people, or receive a “reward reincarnation” as a higher being. You only chance at making all of your lives as good as possible is to work from each one at making the whole world as good as possible. (I take “world” here to mean any part of the universe that affects the lives of people.)


Ultimate Golden Rule: Do unto others as you would do unto your future self. (A lot of people are neglectful of their future selves, but few who are not actively harmful to their present selves are actively harmful to their future selves.)


Every time we have a joy to experience that will be at the expense of someone else (even if its just something as simple as a meal in a cheap restaurant, where the staff are overworked and underpaid), it turns the moral question into a selfish question: what we have to ask ourselves is, how much and what kind of suffering are you yourself willing to experience in order to achieve this joy? Because you will be/were the staff at that restaurant. This should have been the question all along, but the idea that it will be you on the other side of that counter one day makes it very vivid.


            Materialist reincarnation doesn’t just apply to organisms created in the normal way, but also applies to artificial intelligence and, if such things ever come to be, spontaneously generated organisms (such as by 3D printing of an adult human being).


            This conclusion removes my last resistance to materialism. There is no longer anything about my existence that I think remains unexplained by materialism. My misgivings about the possibility of a materialist basis for consciousness were actually a displacement for the concerns raised—and solved—in this essay. Some materialist explanation of consciousness, for example Daniel Dennett’s multiple drafts model, is correct, or on the right track. I’m interested to find out if it does the same for anyone else. I found that all the talk of zombies, qualia, Chinese rooms, panpsychism, and the rest, which I thought were getting to the point of my problems with the materialist view of consciousness, were actually red herrings for the problem I’ve discussed and solved here. I no longer find any of those other problems vexing. I’m curious if anyone else will find this as well.


The mention of consciousness brings up an important point. What in the material world really is this “I exist” I’ve been going on about? It is only a brain that has created consciousness.

I’ve spent this essay sticking rigidly to the internal first-person view: the only question of my inquiry has been “what happens to me?” (or you or anyone), asked from the inside of my own head (or yours or anyone’s). The answer I have come up with I think is the most correct answer that can be given when asking those questions. But I have not yet demanded or even acknowledged the need for any account of why objective reality should behave this way, why this should be the truth. The material world creates brains and beings that are conscious, brains and beings that are manifestly separate and countable, and these beings are inevitably, in some sense, all one single “being” when reflecting on itself. Why should this be the case? It seems to really cause problems for my view. Perhaps it does. It doesn’t vex me at the moment, but perhaps it will. But I think such an account is needed.

            I have one phrase that, as some of what I said above, seems too hippy-dippy to take seriously: each person (each “I exist”) is the universe experiencing itself. I am deeply ambivalent on the possibility of being quoted on that. But this leads to another serviceable metaphor: each person’s existence is like an eye, and the universe has billions of them. One opens, another closes, it is just a vantage that is gained or lost, nothing more. Or: each existence is a portal. These don’t quite get it right either, because they imply that there is one knower behind these eyes or portals, and I do not think we have any good reason to think there is.

But they feel like a start to me, to finding an objective reason for why you should you find yourself as another conscious being when you die. For finding an objective, third-person way of conceiving of it. It is impossible to be a non-experiencer, a non-existent. When one perspective blinks out of being, all that is left is the others, and so the sum total of experiencing in the universe just shifts to those that remain. This is what it means to “become” another of those experiencers. And it has the same status as remaining the one you are into the next moment.

Whenever I begin to think my ideas sound crazy, for example when I try to see it from the objective point of view, I remember that I find myself this conscious life right now, and that that fact is so incredibly unreasonable as to boggle the mind—unreasonable odds and total lack of reason for being anyone at all—if I think that this is the only life form I could have ever been, and that if I hadn’t been this one then I would never be at all. So, sometimes, just the fact that I am someone now is enough to convince me that I would be someone as long there were someones to be.


I suppose many people would find it laughable that I’m treating the objective view as a minor side detail to be worked out later, but this is not the case. First, I do not consider it a minor side detail. I just don’t have a complete answer myself, or have not yet come up with words to explain what I think the correct answer is. Second, I am only flipping the script on the way most philosophers operate when they talk about human existence. Most philosophers work out an objective view of personal existence and take the subjective/internal view as irrelevant, or barely bother with it. Or if they do take up the internal view at first or even for a substantial portion of their philosophy, they ultimately abandon it anyway, in favor of a rigorous and respectable objective view. I’m simply filling this lacuna, but not in the process denying the need for an objective view.


            What are the limits to “who” or “what” you will exist as? One of the famous running jokes in transworld identity is (or was) the question of whether you could have been a poached egg. I get this from David K. Lewis. Lewis’ counterpart relation is loose—he says your counterpart in another world (an alternate history of our world) could be almost anyone, depending on the relations of similarity you wish to emphasize. It is not necessary that it be from the same gametes. (I have written an essay on the relationship between my view and Lewis’ counterpart theory, which is available on request. Superficially, it seems that Lewis’ counterparts might be the same thing as my view, but I don’t think this is the case.) Without such a limitation, your counterpart could be anyone, or even anything. Could it be a poached egg? In other words, could you have been a poached egg?

            Of course not. A poached egg has no brain, and so no consciousness, and so is not anyone. But where to draw the line then? What counts as something with an existence? After all, consciousness is not a yes or no proposition around the edges. Both in the development of a single organism, and in the evolution of species, there is not always an answer to the question of whether an organism is conscious. On the broadest view of materialist reincarnation, being everyone, this is not a problem, because you just become those things/organisms that are someone, when they are someone, and are not them when they are not. As I said is something that makes it appealing to me. But still we might want to know, could you be a cockroach? Is part of materialist reincarnation existing as every cockroach that ever lived? Because I think that would kind of suck.

            But I think not. There is surely not nearly enough cognition in a cockroach to count as being anyone, as being an “I exist”. We often think that we don’t know, or can’t say for sure, whether some animal is “conscious” or not. But I think we can know more than we think we know. We all have access to what it is like to be a being with a much lower level of knowledge and cognition than we have now. We all were such a being, as children. And many of us have access to some memories from this time. It varies from person to person. As I said, my first memory is from when I was 2 (I think; I don’t actually know how or when that meta-data arrived in my mind, but I feel it was quite early). I’ve met people who thought their first memory was as late as age 5 or 7.

            But let me consider my memory. I remember going up and grabbing the toy from the other kid, and being scolded, and then crying and feeling terrible. (I believe I felt bad not only for being scolded, but because I reflected on what I did, and knew it was wrong, knew in some sense that I had hurt someone. This is a good chance to reflect on free will. From my current vantage, I feel that I absolutely did not have free will then. I was just doing what I did, by instinct or whatever else. But as my memories get successively later I begin to feel more and more that I was free, that I could have chosen otherwise.)

            But back to this first flickering of a memory. First, however limited in relation to me now, there was still an awful lot of cognition and brain power in me at the time of that memory. And that’s (ostensibly) my first memory. In some sense, we can say that that is how much cognition is required to be conscious. In the time of Joe Kern before that, there was not enough to be conscious, even though there was quite a lot (much more than a cockroach).

But I have a counterpoint to that: I don’t feel like I was unconscious before that time, and just popped into consciousness then. What is actually significant about that moment is just that I have memory access to it now (see next section.). But I think I was in some sense conscious before that. But not for the entire time of the existence of the human being Joe Kern before that. Certainly not at the zygote stage. (Again, no brain.) And not even much later, when some brain was present. I must have faded into consciousness (note that this is saying something different than saying I faded into being an “I exist”), and then started having memories of it. That’s the account that seems most plausible to me at least. But the main thing to draw from my first memory is that an awful lot of cognition and knowledge is requires before anything even approaching consciousness is reached.

            I sometimes compare this first memory of mine with the consciousness of an adult deer. For some reason this story resonates with me, though I haven’t yet worked out all the implications and aspects. I imagine being a deer. I specifically imagine being a deer who was just spooked and is running. I more specifically imagine just the moment right after being spooked, hopping over a mostly buried mid-size rock (the size of 2 or 3 basketballs). What I’m actually imaging though is not doing this, but having a memory of doing this later. And I mean, being a deer having this memory. But what would it mean to have this memory? I, as the deer, must be contemplating it. Is this something deer can do? Possibly, but possibly not. But I feel sure that chimpanzees and gorillas can do it, and that cockroaches cannot. Somewhere in between this ability to “contemplate” or reflect on a memory simply ceases. I suspect some deer might have it in a very limited way. But anyway, let’s just say that this deer can do it. When I think of this deer memory, this flash of “consciousness” of jumping over a rock just after being spooked, I am relying on my earliest memories of being a human. So what does this sort of memory consist in? I think it consists in something like suddenly becoming aware that I am doing an action, rather than just acting, as I did all the times before. This is what I feel my first memory consists in. It is noticing that I am doing something. Asking the question of myself, though not in words, “what am I doing? What is happening? Why am I doing this? Because I’ve been spooked.” Though, not having a memory necessarily even of what spooked me.

Some people think language is the necessary ingredient for this. But I think chimpanzees and gorillas have these thoughts, have these specific memories, and not just the vague subconscious body memories that cause conditioned response.

I don’t have a specific point to any of this. I just want to conclude by saying that some people would find it detrimental to my theory that what I’m calling personal existence is, in the reductive end, just consciousness, and that there is no clear line of demarcation between what is and is not conscious, whether going down the chain of complexity in species or backward in the development of an individual human. But I do not. I will be whoever is someone, a personal existence (humans, chimps, maybe deer), to whatever extent they are, and whenever they are or become, and not be whatever is not anyone (cockroach, poached egg). We don’t need a clear line between the two, nor do we need to know how to demarcate it.


            There is also the idea that total psychological change within a single persisting physically continuous (through time) human being (for example, through total amnesia) would be the same as the death of one human being and the coming into existence of another. This I affirm. Before, I denied it, because I thought the persistence of a human being or brain, no matter what changes in content it undergoes, preserved something, a personal existence, that the destruction of that human being or brain would make disappear. But on my new view, I see that the destruction of a brain or human being doesn’t make that thing disappear, as long as other consciousnesses exist. So it truly is the same, to change completely the content of one persistent human being, or to destroy that human being and create a different one anew. But not because the total change of content of the persisting human being destroys that persons existence—it does not—but because the death of that human being doesn’t destroy it either. It is the existence of any conscious being at all that preserves personal existence.

            The idea that total psychological change is the same as death and the birth of a new person has been affirmed before, but never in conjunction with denial of the gamete-dependence claim. But it seems to me tenable only on that denial. Denial of the gamete-dependence claim was the true content of this belief all along.

            At the very least, the gamete-dependence claim can be said to have no meaning at all on this belief. Because if total psychological change results in the pre-change person not existing, then a totally different life from the outside (e.g., pirates kidnapping an infant after delivery) also results in that exact same pre-change person in our world not existing. Yes he or she comes from the same gametes as the infant kidnapped at birth. So it doesn’t carry much meaning to say “I wouldn’t exist if those gametes hadn’t joined”, because what you really mean is “I wouldn’t exist unless everything had gone exactly as it had up to the present.” (Or, probably such a person would affirm partial existence, since to them existence is just content, and say “I would only somewhat exist or not exist at all unless everything had gone exactly as it had up to the present.”)  What such a person actually believes is the everything-dependence claim, not the gamete-dependence claim. The gamete-dependence stand in relation to this belief the same as the Napoleon-dependence claim does to the gamete-dependence claim (“had Napoleon not lost at Waterloo…”). In other words, on the gamete-dependence claim, everything before the gametes determined whether you would exist as well. The T’ang-Dynasty dependence claim, the Carmen-Miranda dependence claim, and the Jimi-Hendrix dependence claim would also hold on the gamete-dependence claim, but we don’t mention believing in them. So too would a person who believes as I have described have to believe about the gamete-dependence claim. There would be nothing special about it to your existence, that all other events before the present didn’t also share.


            So what is a single existence then, on my view? In other words, what is my existence through the lifetime of the human body Joe Kern, if the “I exist” of the Joe Kern of the past and the future has the same relationship to my present “I exist” as the “I exist” of any other human being? A single existence is just one with memory access to its other parts. I have memory access to the internal life of the Joe Kern of the past, and so that’s what makes me/us call it a single existence. But it’s just a convention of language. One wisely chosen, to be sure, as there is much to be gained from calling an object one thing when it is physically continuous through time, in most cases at least.

            But this lets us see another point. If there were a period of the life of Joe Kern that I had no memory access to right now (if I had amnesia about that period), then the personal existence of the person of that period would be identical in relationship to my present personal existence as the personal existence of all other people. Other people are just cases of my personal existence to which I have no internal memory access either.

            Sometimes people drink a lot of alcohol and black out. This is where they continue to move about and speak and interact with people, but when they wake up the next morning they have no memory of it at all. It’s just cut out of their stream of time. When told of their exploits, they might say “I was unconscious that whole time”. But I don’t think this is right. I think the person was conscious. They just forgot everything they were conscious of at the time. (I’ve never experienced this type of black out.) But they existed then, they were conscious, were a person.

            And so too, as I said, about our youngest selves. We shouldn’t think that our first memory was our first moment of consciousness. Rather, it is the first one that we have memory access to today.


With my new view, we have (as far as I’m concerned) a complete understanding of our own existence, from the big bang to the accidental creation of replicating molecules which turned into genes which turned into conscious organisms[81], and now we (or at least I) understand why the coming to be of any consciousness necessarily entails the coming to be of me. I find this amazing. I was born into a world of mysticism, souls and God and heaven, where fundamental questions were just assumed to be beyond our ken, and it was even thought that removing the mystery would be terrifying or at minimum make things quite boring, and in the period of half of my life (if I’m lucky), have come to live in a world where we actually do understand ourselves, and many of us find it not terrifying at all, but relieving and comforting. We know what we are. We know the answer to the question, what are people? I can look at the whole universe and know my place in it, why I am here and where I came from. There is no essential mystery to it. This a tremendous and powerful thing.


And so we seek to find meaning in this material world. It is the only world we will ever have, and each of us will have it not just for our own life, but as long as conscious life exists. Thus we can put our efforts into making it the best world we can, and therein find meaning.

            In the past many people have found this unsatisfactory. They have found this world to be meaningless, but have found comforting the thought of god and an afterlife to save them from this meaningless. But I think it is not any particular facts about what god and the afterlife are that give them the feeling of meaning, it is the mystery itself of god and the afterlife. God is an unimaginable being, and so all of the mysteries we find on earth we can just say, well God knows, so I don’t have to worry about it.

In other words, people think that mystery equals meaning. But this is a mistake. Finding meaning only in mystery just means that we don’t have a sense of what meaning would look like if we found it. It is not finding meaning at all, but refusing to find it, putting it off.

But we can find meaning, just in facing up to the truth of what we really are, situating ourselves in reality in a completely honest way. There’s several ways.

            I agree with David Deutsch that we should consider ourselves at the beginning of infinity. We are not just some insignificant scum on a rock floating in space. As knowledge-creating beings we are already among the most powerful forces in the universe. And given millions or billions more years, we/our evolutionary descendants could become more powerful than any force in the universe. We could master time and space. The idea that this “we” necessarily includes you and I both existing there makes these facts even more meaningful to our present selves than they would be otherwise..

            Perhaps, in our great wisdom at that time, we would decide to let the universe end. Perhaps we will long for the naivety of simpler organisms. But wherever conscious life arises, including in other universes after ours ends, you and I and we will be there. Far from our existences being precarious, we cannot annihilate ourselves, for even if we do, the multitude of universes, if it is infinite and eternal, will by happenstance produce other conscious beings eventually, and we will find ourselves there once again. Your existence is not precarious, it is inevitable. (The question of why does something exist rather than nothing not withstanding.)

            But I don’t want to make this sound like a power fantasy. When I say we are powerful, and can shape our reality, not just socially but through actual manipulation of the physical universe, I don’t mean it in an egocentric or dominating way. I just mean that we are not insignificant. We are incredibly unique and special, and in conceptual space quite large, even if tiny in comparison to the physical size of the universe. The effects we can have, by organizing matter through the implementation of knowledge in ways an unthinking universe would never do[82], are significant even now. The configurations of matter that now exist on earth are absolutely unique in the entire universe (assuming we are the only knowledge-creating beings in the universe). And given time, they may become as large as astronomical objects. Whether this is good or bad is a matter for debate. But we are not insignificant.


And if the progress of mankind, either moral or scientific, does not give you a sense of meaning, no matter. You are free to indulge in the better side of your animal nature, and just love and enjoy the company of others, or take joy in having children and your family life, just appreciating each moment as it is. I do not think this a lesser way of being than finding meaning in making progress. There is no basis to judge one or the other as superior.

Or you can find meaning in appreciating the creations of art, and/or in creating them yourself. This is a matter that one might say admits of some progress. Or if not progress, then just change, reactions to the new. One can just find meaning in the moment in the creativity of humanity, or one can fine meaning in seeking progress and the new in these creations.

I find both in my greatest artistic love, music. I love re-listening to the classic songs of my youth, and I love seeing how new artists keep evolving new sounds and idioms. I can spend many hours just focus on these things in the moment they are happening, and find all the meaning I need from the universe during those times.

In any case, you don’t have to take the broad view (future, progress) in order to be satisfied with a purely material existence. Just focusing on the moment is enough, if that’s all you want to do.


            On my new view of existence, I no longer have such great concern that my own life go as well as possible, or that I fulfill any potential I might have to the greatest extent possible. This physical world is the only world I will ever have, but my own existence isn’t my only chance to exist. I am not a thing that popped into existence and then will pop out again. I am one small piece in a great flow of matter and knowledge, and I need only do my part, to improve the knowledge of this flow, or the contentment of the members. I will have successes and failures, but in the scheme of things losses and missed opportunities are not so great a tragedy. The whole is much more important than just my part of it. Feeling myself a part of the flow of everything, and existing as that flow, rather than just locked inside this one precarious thing (this body), has completely changed what it is that matters to me.


            Why not believe in a soul, if the materialist reincarnation solution to the problem with the gamete-dependence claim is too far-fetched? Why not stop at Part I, and the mystery? I think there’s a lot of reasons not to believe in a soul, some of which have come out here already. The divisibility of a single consciousness, as in a split brain, is one such reason.

The fact that we know that content is embodied in a brain is another. So if there were a soul, I would insist that it would be a featureless one, just a raw existence, with content written on it by a brain.

            But there are still problems. What if right now your soul vacated your brain and body, carrying with it no content, and a new one came to be in its place, immediately adopting all the content of your brain? What difference would this make? I think none at all. It could not be detected, and would make no difference to any human being. If your personal existence vacated your body and went into that of the nearest person to you, adopting all the memories and other content of that human being, you would not experience suddenly being that person. This idea of a featureless soul is a concept that has no function. I think other philosophers have mentioned similar points. (Possibly Kant?)

            There is another point, that I haven’t seen elsewhere, and it is hard to put into words, and I suspect my words will be insufficient to get many people to grasp what I mean. It is one of those things that came to me in a flash of insight, a eureka moment about how incoherent the notion of a soul really is.

Say there was a God out there creating souls to put into bodies, as I know many Christians believe and possibly people of other religions as well. When God created one particular one, yours for example, what would he be creating? What would he have in mind that would make it you? There he is out there creating soul after soul. So, after creating, say, a million souls, a million people, what would then be the content of his next thought: “okay, now I’m going to create [or insert your name]”. What would he be picturing, before he created you, that would then make it be you? There is nothing he could be thinking of. Nothing he could do to make it essentially you, to bring you into existence.

From the outside, from a third-person perspective, there is nothing that can be a concept of creating another “I exist”. The only thing distinguishing about an “I exist” apart from content is whether it is yours or another persons, any other persons. Think of a specific person, sibling or friend. If you were tasked with creating their personal existence, but not another one, only theirs, what would you think you were creating? (Content aside, remember.) There is nothing to imagine here. A particular personal existence is unimaginable from the outside. It only seems to be a specific one from the inside.

A religious True Believer would scoff at this thought exercise, believing simply that God can do anything he wants. If he wants to make logical contradictions true, then he can. If he wasn’t to make 1+1=3, then he can. And if he wants to create entities that we find incoherent, he can. I suppose there is no arguing this point, but I can say that if this is your refuge from my point, that God can do anything, then you are admitting that a soul is not what you think it is anyway. You think a soul is something that you understand in some essential ways (if not totally), something that is basically coherent to you: it is you now and your continued existence after death. But if you understand my argument above, then you will see that it is not a coherent concept. And so you are retreating into a mystery if you simply say God can do anything, even create an entity that is incoherent to us. You say souls exist but they are essentially mysterious, something that only the mind of God can understand. This is a different concept than what souls are traditionally thought to be.

But probably most people who retreat to the “God can do anything” defense are not claiming this. What is actually happening is that they are not understanding my argument, not understanding why the concept of creating a soul is incoherent. (At this point in the draft, I have probably not put it into sufficiently clear words what the problem is, so though it may never be an easily communicated argument, right now the fault may lie with me especially so.)

            This incoherence of creating a soul is more fodder for the idea that your personal existence really just is existence itself, full stop. It is not a particular one. It doesn’t make sense to count existences.

            (The idea of God specially creating you and a few billion other people brings up another point: would this mean that there are an infinite number of other possible souls that he has in mind but that he is choosing not to create, not to actualize? If he somehow has in mind what it is he is about to create when he creates you, then does he have an infinite number of people in mind that he could create but chooses not to?)

And once we see this point with a featureless soul, we see that it applies to even a soul with features anyway. Whatever features any soul has, a second one with identical features could be created, compossible with the first. And we are back at the same question: what would god be creating to make that soul “you”?

            The idea of the soul I think comes from our egocentric vantage on the world. We think we are not merely a collection of characteristics. We are an essential self, with this outwardly displayed tacked onto it. If we are religious, we think God created that self specially, with love and care and deep and thoughtful intention, and considers it unique and special, and once created, it will last for eternity. We see this egocentrism reflected in our sometimes desire to be taken by others not just as the characteristics we present to the outside world, but as our true self, the person we are inside. But of course this is all we are, is this set of features. There is no essential self under the features. There is no such thing as unconditional love of this essential self, either by a God or by another person. There is just love of features.

Perhaps one such feature could be, “is my offspring”, in which case a parent might love that being no matter what other features it takes on. But this is still a condition, and so different from the unconditional love people imagine God having for them. Although, I think this dream of unconditional love from a supernatural being comes from the way our ego reacts to the unconditional love we get from our parents (or the desire for it if it was not there.) A parent loves its child not matter what. This expands our ego, leading us to think that it is possible to be loved unconditionally, for someone to see the true me inside, aside from characteristics. Our ego becomes huge. And we dream of a god who can do this. But the truth is, we are nothing but characteristics.

I think religions that promote this belief that God created you as a soul are in some sense essentially egocentric, ego inflating. They want you to believe that your ego, your essential self, has a special connection to this God, that God created it purposefully.

            I think my new view is a real challenge to the ego, which I think is one of the great banes of humanity. If my view can break down the ego, the psychological concept we have that makes us see ourselves as an essential unique existence—and among other things takes affront at challenges to this precious self—rather than as just a set of characteristics, then I believe it will be a great improvement.


            I find the argument for the quantum multiverse (as given by David Deutsch) to be quite convincing.[83] But I don’t want to believe it. So I mostly just ignore it and hope it will go away with some new discovery or argument. But if it were true, and my view true as well, then that would mean that we live not just every life in our universe, but every life in every possible universe. This is very unappealing. It seems an awful lot of time, for one. But of course, even if our single universe is part of an eternal recurrence, then each of us will exist for an eternity. And isn’t this what we want? Or do we want to cease existing? (It probably doesn’t matter, for to exist even once is to exist for eternity in some sense.) So if eternity is what we want anyway, then why does adding a multiverse change anything. It perhaps doesn’t, but still, it multiplies the number of people whose lives we have to live through immeasurably. It is as if I thought I would be living one life for every whole number on the number line, to infinity, and then discovered that I would be living one life for every decimal between the whole numbers. There are an infinite number of numbers between every decimal number. This makes existence seem exceptionally Sisyphean.

            The quantum multiverse in unappealing for another reason. It means that no efforts at moral progress make any difference, because every physical possibility will be realized in the multiverse. Thus, there are some portions of the multiverse where there is nothing but unimaginable torture and suffering. Just the brute physical and logical possibility of it means that it is realized, and there is nothing anyone in any portion of the multiverse can do about it. And each of us will have to live through all of it, if I am right. (There are some portions of our own world where there is unimaginable torture and suffering, but most of us who have the privilege to read and write books like the one I’m writing just pretend it doesn’t exist. It is easy to ignore things that aren’t in your immediate purview. But it is good to now note that we will each have to live those lives, which we know certainly do exist.)

David K. Lewis makes an utterly unconvincing argument that this should not be vexing because what we really mean when we say we want to decrease the suffering or make moral progress is that we want to do those things to our corner of it, whatever extent of it is part of our purview. Since the other worlds of the multiverse are inaccessible to us (Lewis’ multiverse is actually different from the quantum multiverse, but the points about suffering and morality roughly overlap), then it doesn’t matter much. (Someone particular concerned with justice and privilege would undoubtedly find this view reprehensible, but I’m willing to give him the benefit of the doubt, as I know his method of inquiry and theory building.) But I want to reduce the total suffering that exists. The total, quantifying over everything. I wanted to do it anyway, but especially if I believe I will have to live as the each of the suffering people. So I hope that no version of the multiverse story is correct. I hope that, whenever or wherever conscious organisms exist, they will always have the power to shape their one reality in one way rather than another, to prevent certain realities from ever coming to be, and that every possible outcome is not inevitably realized.

I think the fact that we happen to find ourselves in a reality where this is what happens, and where we do shape our world toward good outcomes a lot of the time, is some tiny bit of evidence that maybe this is just the way conscious beings operate. The counterargument, of course, is that maybe this is simply common, which is why the odds were favorable that we find ourselves here. The other counterargument is that even if it is not common, someone had to find themselves there in this exceedingly uncommon situation, and so here we are. But the fact that we know how to do to some extent it makes it seem hard to conceive of conscious organisms who do not to any extent. It’s not a good point or argument yet, but maybe it can become one with a little work.


            But the quantum multiverse does give us some conceptual tools. (I’m sure Deutsch and Lewis both, for their own different reasons, would consider it a cheat to use the tools without believing in the reality.) I can see, to borrow a phrasing from Deutsch, that other possibilities for myself (the human being Joe Kern) are just special cases of other people. They are just other people that have branched off from me after the conception of the organism, rather than before. This diminishes the importance to me of the other unrealized possibilities for the life of the organism I call me right now, and increases the importance to me of human beings who came from different gametes. This is a good visualization to couple with the idea that both DNA and environment are just content shapers. DNA is the first gate for your content, and one of the most drastic. By using the multiverse, we can see all possibilities shading into each other, the extreme outer edges of possibility for an organism of a particular DNA shading into being qualitatively similar to an organism of a different DNA, and this allows us to see all content as a continuum across space and time, rather than as rigid boxes where each box contains an organism of one set of DNA with a clear and distinct wall against organisms of other DNA.

I think DNA has a great influence on who each of us is, and believe many of the claims of evolutionary psychology. But I think this conceptualization helps diminish the overstepping of evolutionary psychology, and helps those who are social constructivists and who view the subject coming into being in a Hegelian/phenomenological sense, come to embrace seeing DNA as just one piece of the puzzle in the coming into being of a subject. It allows us to use the same scale to measure their (DNA and environment) contribution to the character of a subject and of a person, to stop seeing them as fundamentally different kinds of things. Social construction and evolutionary psychology are not at odds with each other. They both do the exact same kind of work on a subject, and both can be ameliorated through awareness of them.


            My new view gives us a new perspective on questions of the type “if I were such and such a person, or in such and such a situation, or living in such and such a place and time, how would I have acted?”. For example, I have often asked myself what I would have done/who I would have become if I had been raised in one of the poor black urban neighborhoods in America. (I say this a “woke” person about the racial injustice of the country I was born and raised in, if I can apply this term to myself.) As a white child of the 70s, 80s and 90s, these loomed large in my consciousness, mostly through media. I was terrified of violence and confrontation even in my own world. How would I have handled the constant threat of violence (and actuality of violence) that people in those neighborhoods were forced to endure? I feel I would not have fared well at all. Alternately, we might often wonder something like “who would I have been if I had been an adult in Nazi Germany? Would I have stood against evil, or gone along?”

There are an endless number of such questions we can ask ourselves. And my view brings clarity to what they are asking. In the past we might have thought it was simply the transfer of a subject, our self, to that situation, and then imagined our reaction. But under my view that is always the case. The subject is featureless, and you are/were there, just with the character of each of the people there in turn. But we aren’t asking what would I have done if I had been identical in content to an actual person who was there. We are asking what I with my content would have done in that situation. But since there is no essential “I” to any organism, then we are actually asking what a person with my content would have done in that situation. And since we are imagining being born into that situation, and therefore that the content that comes from environment would have been shaped by that environment and we would not have any of the content that has been shaped by our own, then what we are really asking is “what would have happened if a person with my exact DNA had been born and raised in poor black American neighborhood, or in Nazi Germany?” (We can add epigenetic influences as well, if you like.) This is all there is to the question of wondering how we would have reacted in an alternate situations like that, where the possibility is not really one that could have come about after our actual birth, because it was at a different time, or did not so affect people of our race or ethnicity. (The fact that race—or our perception of it—is largely bestowed by DNA is something we have to conceptually gloss over here, to fudge a little by not imagining in too much detail, but if one wanted to imagine in perfect detail you could imagine a person with exactly the same DNA in every possible way except those genes that could be minimally changed from your genes to give the resulting person plausible enough characteristics of that so-called race.)

            I realize this problematizes what we want to believe about free will, but that is a separate question.


           I should have an essay that explores in full how I think my view relates to Parfit’s. But I don’t yet. I thought I knew, but when I started writing it, I found I wasn’t so sure, and the essay therefore contained many more qualifications than was readable. I’ve thrown out two such essays already. I will probably have to re-read Part III of Reasons and Persons once again to write it properly.

            In a nutshell, I’m not sure if Parfit is or is not asking himself the question, “where will I be?” or “will I be there” when he performs his extreme thought experiments on human beings. When he says that continuing as a series person is just as good as continuing to exist, then it seems that he is asking himself this question, and affirming that he will be there as that series person. But probably what he is affirming is that there is no answer to that question of whether he will be there, but it is nonetheless just as good as his continued existence in the normal way, as a physically and psychologically continuous human being. I like my answer better.

And I think Parfit’s “just as good as” claim about continuing existence, and claim of empty questions about existence, is incompatible with his time-dependence claim (what I called gamete-dependence claim), because there is a case where some physical happening definitely did result in your existence, and a different physical happening would not have been just as good as that.


Parfit and the Buddha

Similarly to what I said above about my own view, there is some overlap and harmony between Parfit’s Reductionist View of personal identity and Buddhism. Parfit’s Reductionist View is the view I agree with, the view I think is in harmony with denial of the gamete-dependence claim, except for differences noted in this essay, so I take the overlap and harmony between Parfit’s view and Buddhism to roughly correspond to an overlap between my view and Buddhism. Parfit gives some examples from Buddhist writings in Appendix J (502-503) of Reasons and Persons, but I won’t quote these. I’ll quote some statements from Parfit:

I believe my claims apply to all people at all times. It would be disturbing to discover that they are merely part of one line of thought, in the culture of Modern Europe and America.

Fortunately, this is not true. I claim that, when we ask what persons are, and how they come to exist, the fundamental question is a choice between two views. On one view, we are separately existing entities, distinct from our brain and body and our experiences, and entities whose existence is all or nothing. [A soul is the best-known example of what Parfit is speaking of here, though he is trying to be broader.] The other view is the Reductionist View. And I claim that, of these, the second view is true. As Appendix J shows, Buddha would have agreed. The Reductionist View is not merely part of one cultural tradition. It may be, as I have claimed, the true view about all people at all times. (Italics Parfit’s) (273)


Nagel once claimed that it is psychologically impossible to believe the Reductionist View. Buddha claimed that, though this is very hard, it is possible. I find Buddha’s claim to be true. (280)

There is also this from Larissa MacFarquhar’s profile of Parfit in The New Yorker:

Parfit’s view resembles in some ways the Buddhist view of the self, a fact that was pointed out to him years ago by a professor of Oriental religions. Parfit was delighted by this discovery. He is in the business of searching for universal truths, so to find out that a figure like the Buddha, vastly removed from him by time and space, came independently to a similar conclusion—well, that was extremely reassuring. (Sometime later, he learned that “Reasons and Persons” was being memorized and chanted, along with sutras, by novice monks at a monastery in Tibet.) It is difficult to believe that there is no such thing as an all-or-nothing self—no “deep further fact” beyond the multitude of small psychological facts that make you who you are. Parfit finds that his own belief is unstable—he needs to re-convince himself. Buddha, too, thought that achieving this belief was very hard, though possible with much meditation. (“How To Be Good”, The New Yorker, September 5, 2012)

Parfit also says:

Is the truth depressing? Some may find it so. But I find it liberating, and consoling. When I believed that my existence was such a further fact, I seemed imprisoned in myself. My life seemed like a glass tunnel, through which I was moving faster every year, and at the end of which there was darkness. When I changed my view, the walls of my glass tunnel disappeared. I now live in the open air. There is still a difference between my lives and the lives of other people. But the difference is less. Other people are closer. I am less concerned about the rest of my own life, and more concerned about the lives of others. (281).

These are my sentiments as well, but only on with my addition to Parfit’s Reductionist View, denial of the gamete-dependence claim and everything that comes with it. (Recall that Parfit said the above, and presented the entirety of his argument for the Reductionist Vie, on, before mentioning the time/gamete-dependence claim. So he rests no part of his argument for the Reductionist View on it anyway.) The walls of the tunnel fall away for me too. I do not see how Parfit’s view coupled with affirmation of the gamete-dependence claim, as he did, can make the walls of the glass tunnel disappear. To me, they are still there. Death is still total oblivion, just as non-existence would have been had things gone differently before I was conceived. There may be cases of empty questions about existence on Parfit’s Reductionist View, but there are also clear cases of absolute non-existence, of oblivion, and death is one of them. So I still feel the walls of the glass tunnel, on belief in the gamete-dependence claim.

Parfit accomplishes his disappearing trick by shifting his concern from his existence to just the content of his life, and he finds that he is satisfied with the limited continuance of the content of his life in others after his death, until eventually it completely disappears (or would, if he were an average person, who hadn’t written a book destined to live on for long after he dies; I presume Parfit would feel the same though if he were an average person). He says

When I believed the Non-Reductionist view, I also cared more about my inevitable death. After my death, there will be no one living who will be me. I can now redescribe this fact. Though there will be many later experiences, none of these experiences will be connected to my present experiences by chains of direct connections as those involved in experience-memory, or in the carrying out of an earlier intention. Some of these future experiences may be related to my present experiences in less direct ways. There will later be some memories about my life. And there may later be thoughts that are influenced by mine, or things done as the result of my advice. My death will break the more direct relations between my present experiences and future experiences, but it will not break various other relations. This is all there is to the fact that there will be no one living who will be me. Now that I have seen this, my death seems to me less bad. (281)

This is probably an enlightened view, and I’m willing to concede that it shows a greater strength of character than I have, to believe in the oblivion of your own existence but come to not care about it. I have a suspicion of a lingering selfishness in my own view, of my belief in the continued obtaining of my existence itself, independent of content. And so perhaps there is much I don’t understand about this Buddhist view, some level of enlightenment I have yet to reach; it seems that some people really can accomplish this total reduction of their personal existence to nothingness, and accepting total oblivion of that personal existence. And so they would not need my philosophy for their well-being. But I am not there. And I think my philosophy is correct, so it does not matter, unless someone convinces me otherwise.

I take solace in what I mentioned at the beginning of Part V, that my view harmonizes the no self view with reincarnation. This seems to be a point in favor of the truth of my view. So until further arguments come out, this is where I rest for now.

Further Reading

If you want to keep exploring this subject, a lot of further reading paths can be found from the works cited in the text. But I have two in particular that I would take to be most essential.

The Selfish Gene by Richard Dawkins. A very popular book that a great many people have already read, but if you haven’t, do it as soon as possible. For me, it was the foundation of my understanding of the purely material existence of humanity, and is therefore the foundation of my philosophy. Most important is the very short chapter 2, on how life came from non-life through purely mechanical processes. We don’t know for sure that it happened in the way Dawkins describes, but just the fact that life can be accounted for in this general schematic way, that there is no fundamental border between life and non-life or no extra thing that needs to be added to inanimate matter to make it into life, is huge. That this can be done even in principle solves a great many mysteries and problems.

Don’t be put off by the title of the book; it’s not about genes making people selfish, it’s about the gene as the unit of selection in evolution, and how through purely algorithmic and inevitable processes, the most metaphorically “selfish” of genes will be the ones to survive (replicate) in the competition for resources. The influence on those surviving genes on animal and human behavior is a somewhat separate topic that Dawkins also takes up, but for my purposes, the first point is the essential one. (You may also be interested to read the original text in which the word “meme” was coined and defined, which is one of the last chapters of The Selfish Gene.)

Dawkins has become more famous as an atheist lately, but The Selfish Gene is an orders-of-magnitude more important and enduring contribution to the world than the The God Delusion (though I quite like The God Delusion as well). Sometimes I wish that the two books could be taken as though written by a different person, so that the one does not shade or overshadow the view of the other.

Reasons and Persons, Part III, by Derek Parfit. Of course this one. I didn’t write at length about all the ways in which I agree with Parfit, but basically everything in Part III is an argument for my own view of existence, aside from the points of difference I’ve shone light on in this essay (such as over “empty questions”). Parfit does this through a great many fascinating thought experiments, starting with teleportation devices. If you are teleported to Mars, will you travel to Mars, or will you be killed on earth and a copy of you be created on Mars? If my own philosophy is correct, this point is moot, but it’s nonetheless fascinating to analyze it, and Parfit’s is I think the canonical analysis.

And the questions he pursues about value are also essential. For example: what if one day you step into the teleportation device on earth, and nothing happens. Then the technicians say, well, the device malfunctioned; it took a scan of your body, and did create a copy of you on Mars as usual, but it failed to destroy the copy here on earth (you). Also, because of what the device did to your body during the malfunction, you are going to die in about a day. But not to worry: your clone on Mars will still live a normal life, and will take care of your family and all your future plans just as you would have. Would this be satisfying to you? You should read Parfit’s arguments for why it should be.

I want to emphasize that you need only read Part III. I should be embarrassed to admit, I have yet to read Parts I and II. I’m sure I shall one day, but Part III is where the material that relates to personal existence starts, and you can understand it just as well as I have without going through Parts I and II. You can also read the first part of Part IV to see Parfit’s full statement of the gamete/time-dependence claim. (I have read all of Part IV, and it is interesting, so I do not discourage you from reading that as well.)

Dawkins is popular science, so you should have no trouble. Parfit is straight philosophy, not popular philosophy, and so it will be more difficult. But it is much less difficult than most philosophy. He does not use specialized terms without definition, and he does not write as though just dropping into on an ongoing conversation. He starts from the beginning with each of his concepts and arguments, as much as possible. And he writes in very short, declarative sentences, with a clear organizational structure. It can be dry, like reading a user’s manual, but you will not easily get lost.


[1] There’s two different meanings for the word “identical”. Numerically identical means one and the same object. Everything is numerically identical just to itself. Whether numerical identity is retained across time or alternate possibilities is a philosophical question (i.e., whether this pencil is the same pencil as it was one second or one minute or one year ago, or would have been had it been sold to someone else). Qualitatively identical actually just means two separate objects that are similar in every possible way, or at least in every way relevant to the context. In other words, identical in qualities. Such objects can exist at the same time in the same universe. If I use just the term “identical”, as I do even in this paragraph, I mean “qualitatively identical”.

[2] Some people might be having trouble with the modality of PD, because while I am claiming that universe A is this universe and universe B is an alternate universe, in fact both are alternate universes to this universe, and so both would technically have the same modal status. I don’t find this to be a problem, but if you do try this out: Make universe A the actual universe you are living in now, not just by stipulation but in reality. So every detail about your conception and birth etc. is this same as what obtained in your actual life you are living now. For universe B, the difference with universe A would be that right after the copulation event of your parents that produced you, scientists, or even a magical philosophical demon, replace those gametes in your mother with the B gametes, in such a manner that they are in the exact same physical state as the A gametes were at that point in time after the swap, with neither of your parents being any the wiser. What we lose in this version in the ease of imagining all physical facts remaining exactly identical in both universes after the replacement, and the difficulty in imagining where the scientist or demon and the B gametes come from in universe B and where all the players go after they do their duty, when they do not even exist in universe A, and in not having to possibly use magic, we gain in being able to match the actual circumstances of anyone existing today, and thus actually being in universe A. I don’t know if this will help anyone at all, but you can think of PD in whichever way suits you most.

[3] Of course, no one would even have “noticed” if a completely qualitatively different person had existed instead of you either, but I think you get my point.

[4] This belies a prejudice for sighted people, I know. I’ll discuss this a little more in Part III.

[5] The multiverse interpretation of quantum mechanics, on the other hand, poses special problems for PD, some of which would be immediately obvious to anyone familiar with it. I mention this because I actually find the multiverse view very compelling, in fact the only version of quantum mechanics I really understand, thanks to David Deutsch’s excellent explanation of it in chapter 2 of The Fabric of Reality (1998). I’ve consequently given a lot of thought to what it would mean for PD and for the conclusions I’m drawing if the quantum multiverse is the true nature of reality. I’m going to leave those aside for now, though, and instead try to tease out our intuitions about PD as if a single universe is the actual case for reality. Since the multiverse view is controversial (though I find Deutsch’s arguments for why it should not be controversial, in chapter 4 of the same book, also quite compelling), and by far the most common intuitions people, including advanced physicists and philosophers, have about their existence follow from the assumption of a single universe, I don’t think it will hinder the effectiveness of PD in bringing out these intuitions. Once the intuitions and my conclusions are brought out, they can be applied to the multiverse. I’ve got some ideas on how to do this myself, but I won’t be presenting them here. For now, if you do adhere to the multiverse view, one suggestion for understanding PD that I can think of is to change universe A to group of universes A (GOU A), and the same for universe B. I think this can help bring out the same intuition.

The same is essentially true for David K. Lewis’ modal realism, from On The Plurality of Worlds (1986). I’ll come back to both at the end of this essay.

[6] Tangentially: next time you are with a group of people camping, and you go to build a fire—especially if you are a man or if there are other men around—watch what happens. No matter what you do to start, immediately one or more other people around you will assume that 1) they are secretly the best at making fires and 2) you don’t know how to make a fire. And so they will try to take over. The same is true if you ever try to discuss a point of grammar. (And there appears to be no gender-specificity to this.) There are a great many people in the world who assume that in any random group they are likely to be the best at making fires and at grammar. I do not mean to be grumpy and misanthropic. I’ve observed other people doing this to me, and then upon reflection I realized that in fact I go into these situations with these exact attitudes (I’ve been a proofreader for 10 years and I learned to make campfires in high school), assuming that whenever fires or grammar comes up, it is my moment to shine. So I do not only point the finger outward.

I find a similar thing to be true of quantum mechanics, among non-physicists at least. Begin to discuss quantum mechanics among a random group of educated and intelligent people, and there are a great many who will immediately assume that, since quantum mechanics is mysterious and often misunderstood by the lay public, that they likely have the greatest understanding of it of anyone in the room and that anyone else saying anything about it is likely to be speaking from ignorance. All this to say: It is a common reaction to PD to get caught up in the quantum mechanics, and stop there. If I haven’t argued you out of doing this yet, perhaps my analogy with fire and grammar will shame you out of it. You’re welcome.

[7] If you find this argument skimpy, I’ve got more on this subject in Part II.

[8] An interesting thought is to imagine an alternate life for yourself, and then imagine an identical twin actually leading that alternate life in this universe we are in now, matching it atom for atom. An identical twin would be a perfect doppelgänger of your alternate life, and if he or she was someplace you’ve never been, could even be existing right now in the universe you inhabit.

[9] I think Dennett makes this point most famously in Consciousness Explained, though I don’t have a specific citation.

[10] The muddle of the previous paragraph is more of the type an analytic philosopher would make.

[11] I suspect that a great many people were previously unaware that the term “philosophy” can refer without notice to two very different practices and disciplines. If you want to find out what kind you are, perhaps to help you sort out any discrepancies between what you may be expecting from a work of “philosophy” and what you will actually get with the present one, I’ve included further quotes from the book and some notes of my own at (which started out as this footnote, but just got too long).

I self-apply the term “analytic philosophy” to this work not to brag or to try to accrue some sort of authority or power or prestige to the text or myself, but just because an honest assessment leads me to believe that, if any category has to be applied to it, “analytic” would clearly be the right one, and so stating this explicitly might help avoid some confusion. I’m as happy to abjure categories as anyone though. You don’t even have to call this philosophy if you don’t want.

[12] This has been a common reaction to The Selfish Gene. I’ll present some quotes on this in Part II section 2. I’ll also devote a short section to meaning in a material universe in Part V.

[13] Perhaps you’ve never had such an experience. This sort of philosophical impulse, while not necessarily connected to education, may not be all that widespread. But it is similar to an experience that perhaps you have had: suddenly catching yourself having been feeling for a brief period of time very happy and content or even excited about something, and then a few moments later realizing you have no idea what that something is, and then a few moments later finding yourself sinking back into a regular everyday feeling because you can’t remember what the reason was for the joy, or even sinking into a slight depression at the loss of both the reason and the joy, or frustration at not being able to retrieve it. You cannot regain the feeling without the reason, but for the life of you you can’t think of what the reason was, and may even suspect that there was no real reason, that you just subconsciously made something great up in your head and started believing it before you caught yourself and remembered the difference between reality and imagination. Or maybe you even do remember the reason, but when you recite the words to yourself that explain the reason for the joy, but they don’t spark any feeling even though you understand their meaning.

I recall one such incident clearly myself, from around the same time as the existential insight with my brother above, around age 5 or 6. It is a little different than what I just described, because the moment of joy wasn’t just a fleeting minute or two, but a whole evening, but the effect is the same. I was sitting at my desk one night just before bed, and stuffing little pieces of paper on which I had written dollar amounts into a glass bottle, as though I were creating a piggy bank. I kept writing larger and larger numbers on the pieces of paper, numbers with so many zeroes I hadn’t even encountered them before. I just realized you could add as many zeroes as you liked to a number, but every time I ripped another piece off I cautiously added only a few more zeroes than I had the last one, as though too much exuberance in one step was not an acceptable move. And then I discovered that nines could written instead of zeroes. For some reason, this filled me with a great joy and contentment, through some combination of my inherent fascination with mathematics and some inherent love of money. I went to bed, and drifted off to sleep staring at the bottle in the darkness with a feeling of overwhelming well-being, that somehow everything was going to be great because of this project of mine.

When I awoke in the morning, I looked over at the bottle and felt nothing. I remember exactly what I was doing and why I was doing it the night before, but it gave me no feeling whatsoever in the morning. And try as I might, I couldn’t recapture the feeling. It just seemed really stupid, and I felt embarrassed for my exuberance about it, thinking that somehow stuffing fake money of my own creation into a bottle had meaning, or was a cause for joy.

In this case, of course, it actually was stupid. (Though, I was only five, so I have forgiven myself.) But the result was the same as in the existential musings. At a later time, I could recall the form and function of my musings about my own existence, but with no feeling attached to them anymore, they seemed pointless and empty.

[14] I found Chalmers through neuroscientist Susan Greenfield’s The Private Life of the Brain, which I got because it was the first book on the topic of my intuition that I found for cheap at a used bookstore; I started delving into the literature on this with no guidance whatsoever. Greenfield criticizes Chalmers’ thesis in the introduction, and her description of it made me realize instantly that Chalmers was where I needed to start. My reading list has been growing exponentially ever since (this was the summer of 2006). Initially it was just an attempt to find out if I’d been beaten to my “discovery”, or refuted, but it quickly turned into an education in a million things I had never even considered before. I highly recommend to everyone this method of getting into philosophy, rather than the famous-name-based or chronological method that seems to be most well known. Find a problem you care about, and dive in.

[15] More precisely, the claim that since we can at least conceive of such a philosophical zombie, whether or not it could exist, then this must mean that the “hard” problem is a real question. I suppose this manner of posing it shares a family resemblance to my claims about DS.

[16] I think. Although a back-of the envelope calculation seems to indicate that it has probably happened thousands of times in history that a human male has produced two genetically identical sperm. A man produces about 2 x 1012 sperm in a lifetime. The number of genetically different gametes a single human can produce is 9 x 1018. I got this number by multiplying the number of base pairs in the human genome by itself, 3 billion. I have no idea if this is the right way to get that number. I guess it first assumes the guy has a different alleles in every position, which I believe is absolutely not true. But even then, I’m not certain multiplying the number of possible variations by itself is the correct way to arrive at the quantity I want. But assuming it is, then we can take 9 x 1018 as the maximum; the actual number is much lower. So, going with these assumptions, would mean that at most there is a 1 in 4.5 million (18-12=6, so 106, and 9/2=4.5) chance of a single man producing two identical sperm in his lifetime. Of the 3.5 billion men living now, if they all lived to 70, then about 750 would produce two identical sperm (under these assumptions). Of the 50 billion men who have ever lived, 11,000 have produced two identical sperm.

I would of course be grateful for someone to tell me the right way to do this calculation. I would not be surprised to find I was off by a two-digit exponent order of magnitude.

[17] I borrow the capitalization of Vast and Vanishing from Daniel Dennett’s version of Borges’ Library of Babel in Darwin’s Dangerous Idea. It just means many orders of magnitude larger than “astronomical”, for example astronomical distances.

[18] I’ve recently learned that this type of difference is called a haeccity. I won’t be using this term, but anyone interested in the topic will recognize what I’m saying as being about haecceities.

[19] An indexical is any word that depends for its reference on the context in which it is spoken. “Now” is an indexical because its referent depends on when it is spoken, and “I” is an indexical because its referent depends on who speaks it.

[20] Which seems to have a rich tradition of use, misuse and abuse in the philosophical world, often tongue-in-cheek. Consider my labeling of this view as “Butlerian” another example of at least one of those three (or four) things. It’s certainly not fair to Bishop Butler (who no longer exists to be fair to anyway), because, from what he himself wrote about the self, it doesn’t seem that he would have thought this expression applies to persons in the way I’m using it. But I think the dictum nicely sums up the belief in a way that trying to explain indexicals to people who have never heard of them would not, and using the term “Butlerian” to call back to this is less intimidating than the term “indexical”. The very small number of people who do not fall into this set will have no trouble substituting the term “indexical” for Butlerian every time they see it from now on.

[21] Parfit does think that the question his essay is addressing, “why is there something rather than nothing?”, is a good question, and so Parfit and Magee (from the quote that started this section) are in agreement on what are and are not good questions, as are probably a significant percentage of other philosophers as well.

[22]  They might also answer “because of evolution”, but of course this is not an answer to why any one particular human being exists, but to the question of why human beings exist.

[23] This is the date of his lecture, and therefore the date the ideas in the lecture dropped into the philosophical community (like a bomb, it seems). The actual copyright date of the book is 1980, as it went unpublished outside of the proceedings of the conference until then.

[24] I’m basing this surmise not on a comprehensive knowledge of the field, but primarily on the two others besides Kripke whose work on transworld identity I’ve read most extensively, Penelope Mackie and Graeme Forbes, and also on David K. Lewis, who alongside Kripke exerts a foundational influence. I have read bits and pieces by other writers as well.

[25] Better: “I don’t have an explanation of what an explanation is”. I didn’t state it this way because it sounds like it’s supposed to be ironic, but it isn’t. I feel I know what I mean by “explanation”, but I cannot explain it non-circularly. And I am convinced by David Deutsch and his take on Karl Popper, that our judgment of good vs. bad explanations are what distinguish knowledge from falsehood, knowing that in principle we can never be certain of anything, but simply continuously make conjectures and seek refutations. So it seems I should be able to explain what and explanation is. But I can’t.

[26] Of course, most people who claim that DNA and parentage were necessary for them to come into existence aren’t thinking of the possibility of their parents producing two sets of identical gametes, or of identical gametes coming into existence by means of another method of production, such as other people or artificial manufacture. Perhaps they simply believe a) they are their DNA, and that b) only their parents could have produced a person with that DNA, and c) their parents could have only produced one set of gametes to produce a person with that DNA. In practice, b) and c) are so extremely close to being true—due to extremely long odds and the lack of any special technology for overcoming them in the foreseeable future—that it is understandable for people to not be aware that their stated conditions couldn’t possibly be exhaustive.

[27] The reason for this is clearly because, when people mention these factors, it’s usually the context of odds, and each factor does so nicely admit of a distinct method of figuring odds (even if in practice finding actual numbers to multiply together would be impossible.)

[28] And of course, those gametes have to find each other to produce you, which is a whole nuther issue I’ll talk about later.

[29] The actual number is a complicated question I don’t know exactly how to go into, but consider that just multiplying by two as we go back in the short term (two parents, four grandparents, eight great-grandparents, sixteen great-great grandparents, etc.) quickly leads us to greater than the population of the world at a given time (1000 years back gives us over a billion ancestors). Consider too that there could easily be an island isolated from all other people, with 100 people on it, which has had a stable population of 100 people for 2000 years, in which case, each person on that island has at most 100 ancestors who were living 2000 years ago, but not necessarily that many.

[30] This makes PD unlike the zombie problem, where the argument of physical impossibility is the entire argument against it. I do think the two thought experiments share a kinship though, in that they are both attempting to point out and isolate something about existence that seems to call out for an explanation beyond the physical universe.

[31] There is, of course, some poetic license in this paragraph. Most brains are probably usually eaten by worms and bacteria long before they can crumble to dust, if they are not immolated first. And a very small percentage of the content of my brain is contained in a small and very unfaithfully copied way in other people’s brains and will continue for a short time in other people’s brains after I die, but this is not at all what I’m talking about here.

[32] I wrote these examples without any conscious knowledge that they related in any way to any existing philosophy. However, they were written several months after my first exposure to Kripke and Naming and Necessity, and when I took a second go at it and related work in the field of naming, necessity, and reference a few months after writing these examples, I realized that they certainly came directly from it. My knowledge of this area of philosophy is still quite limited, and so it is entirely possible that I have misunderstood some basic ideas of it, in a way I feel much more confident that I haven’t in the philosophy of personal identity, and to a lesser extent consciousness. Nonetheless, I still feel that these examples that I wrote with no conscious knowledge of Kripke or this field really do express what I want to get across and at this moment at least appear to me to be really solid, so I’m presenting them anyway.

[33] Obviously Kripkean through and through, but I was reminded of it by Nagel. For this example especially I fear I may be misunderstanding something of the original arguments.

[34] Oxford Dictionary of Philosophy (1996). My knowledge of eliminativism is too slight for me to feel confident commenting on it in my own words, which is why I felt it best to go to the dictionary. As such, I don’t claim that Blackburn’s definition necessarily suits Stone, or that we should consider Stone’s words to in any way be constrained by it. I just hoped to provide some context for my use of Stone’s quote in a moment.

[35] The words between the first part and last part of this quote, on Hume, Buddhism, and the desire for permanence, are a choice slice of elegant philosophical writing as well, though I didn’t notice this until about my fifth reading of them. I point this out because this paper is obscure and not easy to get hold of, and so Stone’s prose is at risk of being lost to time. Here’s another nice portion: “Thoughts and desires represent the succession that contains them as a persisting substance, somehow underlying itself, thereby creating the illusion of the personal, which is cherished and nurtured by moral and cognitive behavior designed to thicken it. The slurring of different beings into one is motivated by the craving for permanence.” There’s a mantra for you.

[36] Though I protested loudly, I absolutely refused myself permission to use the word “transcendental” anywhere in the title at all.

[37] Recall the alternate formulation of PD if this bothers you: universe A is the actual universe, with your actual past (no spaceships and stuff), and universe B is one in which scientists or philosophical demons replace the A gametes with B gametes under the actual circumstances in which you were conceived.

[38] I have an argument prepared for why I think we want it much more than content, but I haven’t included it here, as it was too big a distraction and tangent.

[39] Configuration and process would sometimes both be subsumed into just process, since any change in configuration would necessarily require a change in process, though a change in process would not necessarily result in a change in configuration.

[40] Alternate for scale: 100 trillion bananas (mashed) would take up about 8km3. The effort put into calculations for this stupid inside joke has at least taught me one thing: there are a shockingly large number of cubic centimeters in a cubic kilometer (1 quadrillion, to be exact). I was definitely expecting (hoping) to for at least a few planets made out of mashed bananas.

[41] I had a very long footnote here about the modal correctness of speaking this way, but I’m not sure 1) if it addresses an objection anyone would actually make, nor 2) if I’m any good at arguing about modality. Available on request.

[42] It might seem that “instead of sperm A” needs to be appended to this, but it should be obvious that it is necessary that if sperm A1 were to have been created, then it would have been created instead of sperm A.

[43] And never mind the actual mechanism that would accomplish this fading or blending of existence while content remains constant, such as a soul or swapping out identical neurons or whatever; any possible mechanism for this seems to have problems in itself, but this is not what I want to criticize here.

[44] We could even imagine that there was no second person coming into existence, just the fading of your existence while the human being slowly enters a state of zombiehood.

[45] I hope it will not be confusing that the physical spectrum is performed on an existing brain while the gamete sorites was performed before the creation of the sperm. As far as I can see, the questions raised by the two situations are essentially the same.

[46] In the case of DS, Parfit did not have to be committed to calling it an empty question, because there is no trouble—no arbitrariness—there with just thinking the answer is yes or no, even though the facts of the situation could also lead one to conclude the question is empty. In the case of the gamete sorites, though, one would have to commit to an answer; the arbitrariness in the middle of the spectrum precludes a “no” answer to whether it would still be you, so the only options are “yes” or “empty”. The fact that Parfit said DS may be empty further leads me to believe he would definitely call my questions about the gamete sorites empty.

[47] The one possibility for dispute I can imagine would be on the multiverse view (either the quantum multiverse or David Lewis’s version). But I’ll set those aside for now.

[48] I fear that, at this level of detail, imagining these things of your own father might become kind of gross, if none of this has already, so I’ll at least avoid explicit mention of anatomy. I do apologize, but it’s all in the name of progress in metaphysics.

[49] I probably would have better drawn the dashed fence line after L as only slightly more pitched than the line before, until after conception, when it gets drastically more pitched. But I did not include conception in the diagram.

[50] You might question whether it would still really be sperm A in this situation, being that there is a difference in this universe, the creation of sperm Aa,t, from the way things actually happened, i.e., a difference from universe A. But look at it from the perspective of sperm A. Start by considering the world exactly as it was when sperm A was actually created: no sorites, no sperm Aa,t; just the facts that actually did obtain in reality in our universe when the sperm that produced you, sperm A, was created  Here’s a series of questions to consider: would it still be sperm A if, during its production, something microscopically different had happened on Alpha Centauri than what actually happened in universe A? Would it still be sperm A if something microscopically different had happened in your father’s neighbor’s house than what actually happened in universe A? How about something microscopically different in the hairs of your father’s head? I think the answer to all of these should be yes. The important point is causal isolation. And so too then of something microscopically different happening, whatever it might be, 60cm from the production of sperm A, including the production of a physically identical sperm,. And, as I said, I think causal isolation can likely get much closer than that, but for now 60cm will suffice.

[51] Forbes (1980) is a thorough example of this, and he continues to affirm this as an unassailable conclusion in later writings on the subject. But like all writers on transworld identity I have encountered, he treats the question of personal existence as identical to the question of the existence of an inanimate object.

[52] See This American Life Episode 544: Batman, Jan. 9, 2015.

[53] I borrow this from Simon Blackburn in his pocket-sized Oxford Dictionary of Philosophy from his uncharacteristically short definition of “self” that for many years seemed completely useless to me: “The elusive ‘I’ that shows an alarming tendency to disappear when we try to introspect it.” In most entries in this volume he provides history and background and context etc., but here I think he was rather enjoying a bit of fun at getting to be a dictionary maker and so left it at that.

[54] I think Galen Strawson nicely sums up the situation of the use of the term “self” well in his response to comments on his paper “The Self” (1997), which was on the questions “what is the nature of the sense of the self?” and “is there (could there be) such a thing as the self?”:

I am most grateful to all those who commented on ‘“The Self”’. The result was a festival of misunderstanding, but misunderstanding is one of the great engines of progress. Few of the contributors to the symposium on ‘Models of the Self’ were interested in my project: some…were already highly sceptical about the value of talk about the self, others were committed to other projects centred on the word ‘self’ that made mine seem irrelevant at best and many worse things besides. Large differences in methodological and terminological habits gave rise to many occasions on which commentators thought they disagreed with me although they had in fact changed the subject. (Strawson 1999)

This is similar to the troubles with the term “personal identity” I mentioned in the Prelude.

[55] Among other things, Dennett argues that determinism, far from being the bugbear of free will, is required for us to have the sort of freedom we would want to have, that the freedom we think we want is not coherent, and that even indeterminism (such as come with quantum mechanics) wouldn’t give it to us.

[56]  I didn’t come to any of these ideas through any one source, let alone all of them, so it’s hard for me to give advice on where to start if they are all new to you, but for a single book you could do worse than starting with the aforementioned Descartes Error by Antonio Damasio. He is a scientist, not a philosopher, so is focused more on empirical evidence than arguments, and he writes in the best tradition of clear popular science writing, and thereby can be understood by a wide audience.  Tor Nørretranders’ The User Illusion is another popular science book, and has a nice roundup of the sorts of experiments on actual people I mentioned above that convinced me of some of these things.  Dennett’s Consciousness Explained is thorough, and I recommend it also, but it’s harder to understand than it at first appears.

[57] I use this ridiculous example because I think we can all agree that the North Korean way of life over the past several decades is the one thing that was unambiguously worse than other ways of life. I’ve been all over the world, and I know all too well how insulting it is to automatically assume, from the rich world perspective, that growing up in a “poor country” would be terrible, so I avoided that assumption. I think I would have been semi-justified in picking a country like Russia that has had an objectively hard time in recent years, and is also extremely cold and dark in the winter (I grew up in Minnesota—the United State all the emigrating Norwegians felt most comfortable in—and have earned the right to criticize extremely cold and dark places), but even still, it is not my place to tell Russians that the way they grew up was worse than other possible ways. Anyway, for any South or diaspora Koreans born before 1953, this example is not ridiculous at all.

[58] I could have put the following quote in a lot of places, but I just recently discovered it and I like it here. It seems especially striking after the above analysis of what DNA is to see just how unreflectively DNA essentialism is believed and casually thrown around by even the most rigorous thinkers searching for the most basic examples. Joseph Melia, in his excellent introduction to modality, is here justifying belief in absolute necessity, contrasting it with contingent necessity:

Reflection suggests that we do have a notion of absolute necessity. True, with the physical laws fixed, it is not physically possible for anything to travel faster than the speed of light. But we do not think the physical laws themselves are absolutely necessary. True, with the biological facts fixed, it is not biologically possible for me to have had different genes. But the biological laws themselves are contingent. True, with the laws of arithmetic fixed, it is not possible for 2 + 2 to be anything but 4. But the laws of arithmetic themselves aren’t contigent. 2 + 2 has to be 4.: it absolutely couldn’t be any other number. The laws of arithmetic have to the for that they do: they couldn’t be any other way. True, with the laws of logic fixed, it follows that there are no true contradictions. But the laws of logic themselves are not contingent: the laws themselves (absolutely) could not be any other way. (Melia 2003 p. 17)

(In the spirit of my previous roundup of statements of this belief, I’ll add to this a parenthetical “(DNA)”.)

Melia isn’t writing about physics or math or logic or biology. These are just examples to illustrate his point. He could have chosen anything, but he was presumably going for the lowest hanging fruit. So what strikes me is how well selected and uncontroversial the examples other than genes are. Light being the top speed of the universe has been vetted and tested from all sides for over 100 years. And it is completely clear what the claim means that something could not travel faster than the speed of light. And the examples of absolute necessity even moreso. They have not only a complete and immediate intuitive acceptance—the hypothesis that 2 + 2 might have equaled something besides 4 seems the sort of hypothesis only a philosophical grandstander might tender—but also a rich history of defense in philosophy (because, in the end, everything in philosophy must be defended, no matter how obvious it seems). And then he throws into this mix the connection of genes to existence, a concept which, when we examine it as we have, we see has no basic intuitive appeal—you actually have to do extra work even on an immediate gut level to make the connection between the two, it doesn’t just come for free (this is true even if the extra work you are doing is invisible to you)—and also which has had little philosophical examination to produce any explicit justification anyway. The confidence must come not from the same place as the other examples, but just from universal agreement and lack of notice.

Unless of course Melia is talking about human-body objects. But I very much doubt it, since he used the word “me”. If he meant this and was being careful, he would have said “it is not biologically possible for a different set of DNA to produce an identical human being.” And anyway, in a world where the notion of a soul makes intuitive sense, even if it is unsupportable on examination, the assumption that by “me” you just mean a human-body object doesn’t come for free either.

I say all this not to pick on Melia. The quote is powerful because of how he is otherwise a well-respected and uncontroversially straightforward and clear thinker, and it could be added to the collection from Part I with quotes from Parfit, Nagel, Kripke and Dawkins. And I feel I should add, for good measure, Modality really is an exceptional introduction to the topic. So clear and well organized, it really tied together and contextualized many things I’ve been struggling to understand over the past several years, in a way that other sources purporting to do that frustratingly failed at. I am now a Melia fan.

[59] This is surely well known by almost everyone reading this, but to be clear and precise, both an entire DNA molecule can be counted as one molecule, and each nucleotide in a DNA molecule can also be counted as one molecule. Amino acids are also counted as one molecule, and proteins, which are composed of amino acids, are also counted as one molecule.

[60] I’ve been skirting the topic of how my concept of personal existence relates to the growing of a brain from nothing, and/or the “coming into consciousness” of a person, by which we usually mean the first memories a person has carried to the present. I won’t skirt this forever, but will address it briefly at the end.

[61] We would thus strictly have to call it a different sperm as a physical object, as we did with sperm A1, but I will dispense with that notation and just stick with “sperm A” through changes, and hope you will understand why this does not beg my question.

[62] In this essay, I not only present theories, but also teach many new fascinating facts.

[63] It was in a paper showing why transworld re-identification of an object is not as simple as identification of objects at different times in our own world. But since Quine is talking about objects, even when talking about human beings, as most transworld theorists do, it is no insult to my use of it. I do admit that my use of it was a bit cheeky though.

[64] I’m wondering if it would be correct usage to call these “antinomies.”

[65] Although one could easily imagine a natural disaster causing difference as well. I’m not sure why I chose people acting differently rather than a natural occurrence to cause the change, or if there is any significance in the difference between the two.

[66] We could even rewrite the Socratic dialogue from the Prelude, to better reflect this new belief about existence:

A: I don’t exist

B: What would be the case if life never came into existence in the universe?

A: I wouldn’t exist

B: You mean you wouldn’t exist in the same way you don’t exist now, or in a different way?

[67] Is it possible that there is a reason but that we could not discover it? I agree that there is nothing about being human, a contingent organism designed to function in one specific environment with only a few specific capacities, that dictates that it is necessary that every fact is discoverable by us. But in this case, I don’t think this is a good objection to our quest to find a reason, and discovery that it is impossible. I think the discovery that it is impossible must stand as firmly as any knowledge (I’m a Popperian, so by knowledge I mean conjectures in search of refutations, with confidence increasing as time increased in which a proposition has stood without any refutation). But I’m not clear on my reasons for believing this. I would welcome help in getting this straight, from philosophers with more experience with these ideas.

You may see another problem: I said there is no explanation for why you would be one person rather than another in a splitting zygote/ split-brain situation, and that we just have to accept this lack of explanation. Am I contradicting myself by here insisting we must have an explanation? I don’t think so, but I am not yet clear one exactly why. Again, perhaps I can get straight on this with some help. At any rate, my preferred eventual total conclusion renders this point moot.

[68] I think not too much should be made of how well or exhaustively this diagram represents. It is a very rough idea, and I think it conveys the essential concept I need to convey well enough. Things such as the sizes of the enclosures, whether they overlap, the number of dimensions, or exactly what factors each point is meant to represent (time, space, configuration of matter of the human being, configuration of matter of the universe etc.) should not be worried over too much unless someone has a good reason to, or can improve the diagram’s ability to represent.

[69] Okay, so I tried out a calculation multiplying all the entities in this sentence by each other, assuming all the space in the known universe, an object halfway between the size of an ovum and a sperm (since there’s a 1:1 ratio), every nucleobase sequence of a human-lengthed stretch of DNA (even though almost every one of those wouldn’t code for an organism at all), and one second of existence for each gamete. I bet you want to know what that number is, even though you are gleefully finding fault with these assumptions. Okay, I’ll tell you. 1 in 1,000,000,000,000, 000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000. That’s 1 in 1 x 10120, but such notation can be deceptive; by comfortably fitting into our eyeballs we think it’s also fitting into our brain, but it’s definitely not. This number of things? Imagine you had 1 billion things. Now imagine that that 1 billion things is in one basket, and imagine that you had 1 billion of those baskets. That’s a billion times the number of things you had in the first step. Now those 1 billion baskets of things of 1 billion things each? Put a billion of those baskets into a box. Now that box? Put a billion of those into a warehouse. And that warehouse? Put a billion of those in a solar system. That solar system? You’re gonna need a billion of those too. I’d keep going, but at this point, it won’t help anymore. We’re already way beyond caring, and you have to do that 13 times in total to get to 10120. We’ve only gotten up to six. Actually just a little more: you’d have to then have 1000 of whatever the last thing was. Anyway, you probably feel less incredulous looking at that number than you did with my description of the conceptual space, so just ignore this. Thanks.

Wait, I’ve got another one. You know that number googol that Google is named after? That’s a 1 with a hundred zeros. 10100. Now take a googol number of things, and then imagine a number of things a billion times that number. Sorry, I mean a billion times that number. (Fact: italics helps us to visualize large things better). Now imagine a number of things a billion times that number. Now imagine a number of things a hundred times as large. Does that help any? No? Figures.

[70] People have sometimes speculated whether, if they had a time machine, they would go back in time to kill Hitler. Some even wonder whether they would kill a baby Hitler. One can wonder, why be so gruesome? You have a time machine. Why not just go back in time and take his dad out for a Bier one night, any time before he was conceived? Or, just, you know, bump into him on the street one afternoon. We didn’t need my esoteric metaphysics to know this.

This also reminds me of the first Back to the Future movie, where Marty travels back in time to before he was conceived, and almost makes himself disappear by accidentally taking the place of his father as his mother’s object of desire. But he gets them together in the end, and as his mother and father are falling in love, he fades back into existence. We all knew this wasn’t quite right, but we accepted it because it was a movie. But this bolsters my belief that most people don’t really believe that they and everyone they know are as contingent as the facts we all know clearly indicate. Our contingency is essentially hidden knowledge, because we can’t deal with it, even though we all know it is true.

[71] Please, dear reader, try to ignore how unbearably sad this scenario is.

[72] On some views of time, which I think very plausible, this is an improper use of “now”. “Now” is just relative to a person. So that, if I ask, “where would I be now if my gametes had been frozen for five years and then joined”, then by “now” I should properly mean “aged 42 of that person”, so five years from now of so-called objective time, or more time in our world. I find this a very interesting thought, but I haven’t put much effort into seeing how it squares with either the traditional belief in the gamete-dependence claim or my new belief, so best to just ignore it for now.

[73] “Impossible” in the idiomatic sense of “unbelievable”, not any modal sense. Although I think that’s true too, though I haven’t argued for it.

[74] I think this term is a bit passé these days, but I do not know a better one. I am indeed a child of the 70s and 80s. Anyway, some of what was called “new age” in those days has in the present become pretty mainstream everyday psychological and metaphysical thinking among a lot of post-Christian Westerners. But I think that the term “new age” connotes a system that prioritizes comfort or a sort of nurturing pragmatism over disinterested truth, and so remains an apt choice as a pejorative.

[75] I’d like to think this at least. Being that it is so undeniably emotionally appealing (which, again, I’ll get to in a moment), that is very likely clouding my judgment on what is rational. But trying to ignore this emotional appeal, just the cost to rationality of belief in a mysterious re-existence after death seems less than the cost to rationality of belief in the gamete-dependence claim.

[76] You can imagine creation of a new human being as the sort of putting together of a person that a teleportation device from Star Trek or The Fly achieves (the destruction too, as a matter of fact), without the change in loaction. A person steps into a booth, a scan of every atom in his or her body is taken, and then that information is beamed at the speed of light to a distance location and used to reform a new body out of matter existing there (since matter itself cannot be transmitted at the speed of light). In this way, an object (including an organism, including a human being) can be transmitted just as swiftly as text or images on the internet. Imagining the consequences of such a device to our sense of personal identity is a foundation of Parfit’s philosophizing on personal identity. It is the very first thing he does in Part III of Reasons and Persons. It doesn’t much matter, to Parfit’s thought experiments or to understanding series persons, that this is technologically impossible and may always be so. If we accept that our bodies are just made of atoms, then in principle other atoms could be taken to make copies of our bodies.

[77] I’m sure I’m not saying this right. My rendering probably for example smacks of the Cartesian materialism Dennett warned of. I’m ready to receive assistance in stating it correctly.

[78] It would be tempting to view such a universe, and life for an individual person, as like a film, where each frame is a static photo, but stringing them together produces movement, or the illusion of movement. This is mostly a good analogy, but it has the danger of making us think that each moment is still and so only creates the “illusion” of dynamic reality, when in fact this is what movement and reality really is (or would be, if it were the case).

[79] My understanding though is that, for example, many early Christians didn’t believe in a soul, but rather that their actual body had to be raised from the dead, or a possibly a new body reconstituted to the exact specifications of theirs. So this lends credence to the idea that my gut belief is culturally instilled. But this belief also still stops short of where I’ve taken it: either physical similarity or psychological continuity was necessary for the Christians who believed this way.

[80] The average life span over all those 100 billion people is surely on the order of several decades. Whether it would be 20 or 50 I don’t know, but on this scale it doesn’t much matter.

[81] See Richard Dawkins’ The Selfish Gene, chapter 2, one of the most important things I’ve ever read. I know we don’t know that it happened this way, but just that fact that in principle we can account for life coming from non-life through a series of small plausible steps is enough.

[82] More accurate: is so unlikely to do as to be as good as never. Does everything that is possible occur no matter how unlikely, if the universe or multiverse or succession of universes is infinite? I vacillate on this question.

[83] The Fabric of Reality (1997), Chapters 2 and 4 especially. After Dawkins and Parfit, Deutsch is the third most influential writer to my view of the world, even though I have strong desire to deny one of his main theses, which negates about 20% of everything he has said. I’ve made a reading guide, which you can access at Chapter 3 of The Beginning of Infinity (2011) is one of the single most important scientific and philosophical essays in the modern world, and it can be read independently.

Philosopher’s Introduction and Summary of the Argument

There are two questions about our existence that have gone mostly unnoticed and unanswered.

The first question is, what do you mean when you say “I exist”? What are you actually referring to when you say that? You might think you know the answer to that in your own case, but I think you probably do not. The concept of existence as we apply it to ourselves in the singular first person when we say things like “I exist” (or “I did not exist” or “I would not have existed” or “I will not exist”)—what I’m calling personal existence (and its absence)—is a muddle. To truly understand this personal existence, it needs to be isolated from other factors that confuse our discussions about it. I have devised a thought experiment called the perfect doppelgänger as a first attempt to do this.

The second question is, given that I do exist (an assertion I will justify in the argument), what caused me to exist? There are some standard answers to this question, things such as DNA or a particular set of gametes coming from a particular set of parents. These answers are given not just by laypeople, but by esteemed philosophers and scientists. But if we correctly understand the answer to the first question, what we are referring to when we say “I exist”, then we will see that these factors cannot possibly be causes or explanations of our existence.

This belief that a particular set of gametes had to join in order for you to exist (I take DNA and parentage to be subsumed as properties of a particular set of gametes) I’m calling the gamete-dependence claim. This belief is very widespread, almost universally agreed upon. I have never seen anyone explicitly deny it, so if some do, they must be remaining silent about it, perhaps because they do not have an alternative theory. What this essay does is deny the gamete-dependence claim, and offer a full and justified alternative theory.

The problem with the gamete-dependence claim is that these factors—DNA, parentage, a particular set of gametes—explain why a particular human being came into existence, but they do not explain why the coming into existence of that human being brought you into existence, rather than not. All of the other human beings that exist (or ever have existed or could have existed or ever will exist) did not bring (or would not have brought or will not bring) you into existence, but this one did. Why?

The best answer to this question currently available—when the question is noticed at all—is that “I exist” is an indexical, such as the time that is now. But I think this cannot stand as an answer, if we believe in the gamete-dependence claim. This is hard to explain in a short space, but essentially it is because you understand your personal existence as something that obtains in your human body now, and obtained in the past of that human body, will obtain in the future of it, and would have obtained in alternate histories of it. I think this is the way everyone understands their personal existence. But on the gamete-dependence claim, it would not have obtained in any other human body, i.e., a human body coming from any other set of gametes. In other words, a single person’s personal existence is a thing that consistently obtains across a wide variety of different physical objects, but then suddenly no longer obtains in any other physical objects outside of that set. This is a very different thing than what the indexical concept can be used to explain, in which every one thing is a single point of a same continuous thing. (It also brings up the problem of finding criteria of gamete identity across counterfactual situation, which proves to be impossible; we have to simply make arbitrary stipulations.)

And so I offer the alternative theory to the gamete-dependence claim that I mentioned above. Each of should think we would have come into existence no matter what gametes joined. Even if the world had gone differently and there were entirely different human beings on earth right now, you would be one of them, as would I. As long as some conscious life (or even A.I.) exists, you will be one of them. And if this is so, then there are consequences for how we perceive death. It is not the ceasing to exist that those of us who are materialists—no gods, no souls—have thought it to be. Rather, each of us exists again as another human being after we die. I call this materialist reincarnation. To put both parts of this theory another way, I should believe that other people, no matter what gametes they come from or how similar or different in character they are to me, are just as good to me—to the obtaining of my personal existence—as alternate possibilities to my own life (if I had moved to France at age 2, for example), or the past and future of my life.

Materialist reincarnation is radical and I acknowledge that it is surely unbelievable to any sober materialist. But it seems to be an inevitable consequence of denying the gamete-dependence claim. And I think the gamete-dependence claim must be denied. I believe that a close analysis of origins, of coming into existence, shows that it cannot be true.


This work is closely related to Derek Parfit’s work. I take his analysis of personal identity in Part Three of Reasons and Persons to be correct, and I use this analysis in this essay. But it is interesting that among the very many people who make the gamete-dependence claim, he is one of them. He calls it the time-dependence claim, and makes it right after his analysis of personal identity. (The gamete/time-dependence claim is the basis of his well-known non-identity problem, and so since I deny the gamete-dependence claim, I think there is no non-identity problem.) This is significant, because I think it is much easier to understand his analysis of personal identity—the Reductionist View of personal identity—if we deny the gamete-dependence claim. However, I do not consider this essay to primarily be a response to him, but rather an attempt at a positive theory of my own, in some cases in my own terms.


Private email correspondence and feedback on this essay is very welcome. Start by contacting me through this form. You may also submit a public comment below.


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2 CommentsLeave a comment

  1. Hi, you should take a look at Arnold Zuboff’s work on personal identity (universalism). He has done an in-depth study of this same theory in many works developed over decades.
    Here are links to two of his videos explaining universalism. His other works regarding this topic can also be found online.

    • Hi Jen, thanks for the comment and the videos. I discovered Zuboff just this past summer. Do you know Daniel Kolak? He wrote a large book called “I Am You”, published in 2004. I’ve been working my way through that as well. His distinction between Closed, Empty and Open Individualism (Closed is the standard belief, Empty is roughly the belief reached by my many philosophers, notably Derek Parfit and Galen Strawson, and Open is the view of Zuboff, Kolak, myself, and others) really helped me clarify what I wanted to say in the revision of my book. I recommend at least the introduction and first chapter of his book; you can find a pdf through a Google search.

      I discovered both Zuboff and Kolak through another amateur like myself named Iacopo Vettori who has also written on this idea. He manages a Facebook group centered on this idea where people discuss and share other resources.

      And here’s what Vettori wrote about it:

      I was working in the dark for ten years not knowing any of this exists, but after I put out the first draft of this book I started to get in touch with some of these other folks. I think the idea is building steam.

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