Why You Don’t Exist

I’m very sorry to inform you that I have some bad news. Well, maybe not bad per se, but I think you might find it a little disturbing. You might want to make sure you’re sitting down for this. Ready? Okay, here goes: You might not exist. I know, I know. It’s okay. I understand that it’s difficult to accept. But the sooner you make peace with it, the better. You’ll see. With time, you might even learn to see a kind of alien, ineffable beauty in it.

Since the first stage of grief is denial, your impulse here is probably something like this: “What a load of rubbish! Of course I exist! I can even prove it a priori. You can’t fool me; I’ve read Descartes! I have thoughts and perceptions and feelings. Even if none of those correspond to an external world, even if I’m being deceived by an all-powerful demon or hooked up to a computer simulation, there still has to be a me there to be deceived! Cogito, ergo, sum; I think, therefore, I am!”

It might surprise you to know that many philosophers would deny that the cogito settles the matter. A question that arises here is: What is this “I” that thinks and therefore is? The physicist George Lichtenberg notoriously claimed that Descartes had failed to prove anything. Instead of concluding that there was an entity—an I—doing the thinking, Lichtenberg thought, Descartes should simply have said that “thinking is occurring.”

Buddhists say something similar. As you might already know, the central teaching of Buddhism is the doctrine of anātman, which literally translates to “no-self.” Accordingly, a common Buddhist saying is that “thoughts think themselves.” Of course, there are thoughts. There are perceptions, beliefs, feelings, and so on. But there’s no thinker—no self, no ego, no person—doing the thinking. You can find a pretty similar idea in David Hume.

You might think this sounds insane. Surely, thoughts require a thinker! As a matter of fact, though, several prominent philosophers have thought that something like the Buddhist view is the most plausible thesis we have about the nature of personal identity. Stated simply, that thesis is that there is no you—that there is no self—independent of linguistic conventions. Of course, you do exist in a sense. But what makes it true that you exist is just the way we happen to use language.

I harbour no illusions about my ability to convince you of such a radical thesis with a single short piece. So I’ll aim for something more modest. I’ll just try to loosen the intuitive obviousness of the idea that there’s a you. Just some food for thought… though of course, not for any thinker!

A Trek Through Time

My claim that there’s no self independent of linguistic conventions might seem paradoxical. So let’s be clear about what I’m saying and about what I’m not saying. I’ll need a volunteer to help me illustrate. Let’s enlist our good friend the actor William Shatner. Take the sentence “William Shatner plays Captain Kirk on Star Trek.” That’s a sentence about a person, namely William Shatner. I’m certainly not saying that that sentence is false. That would be crazy talk. That sentence is obviously true.

At this point, you might be starting to feel a little confused. I seem to be granting that there are true claims about persons. But if there are true claims about persons, then surely persons exist. So what exactly am I saying? Talk sense, man! It’ll help to clear things up if we consider another sentence, again with the gracious help of our volunteer Mr. Shatner. Take the sentence “William Shatner starred in Star Trek: The Wrath of Khan (1982) as well as in Star Trek: The Undiscovered Country (1991).”

What this sentence is saying is that the person who starred in one film, The Wrath of Khan, is one and the same person as the one who starred in another film, The Undiscovered Country, nearly a decade later. Incidentally, that sentence is true too. But one question we might ask here is: What makes it true? In other words, what makes it true that the guy who starred in one film is the same guy as the one who starred in the other?

This is the kind of question addressed by the philosophy of personal identity. To use the kind of jargon that makes philosophers look so intelligent at parties, the question is about the diachronic identity of persons, that is, about their identity across time. In everyday life, we talk as though someone at one point in time, say you at this moment, is one and the same person as someone at a different point in time, say the baby your parents had some decades ago. The question is: What makes that true?

This brings us to one feature of what might be called the self, namely, its persistence through time. Think about it. You and I are constantly changing both physically and psychologically. Our cells die off, our memories fade, our preferences, intentions, and so on all change in all kinds of ways. But we tend to think there must be some persistent entity in there, a self, to anchor it all down. Surely the persistence of that self is what makes you one and the same person through all this change!

The claim I want to defend here is that there is no such persistent self. Although it’s true that the guy who played Captain Kirk in The Wrath of Khan is the same one as the guy who played him in The Undiscovered Country, what makes it true is not that there’s an entity beyond William Shatner’s changing physical and mental states that persisted from one movie to the other. What makes it true is, to put it somewhat paradoxically again—how else am I supposed to get you to keep reading?—linguistic convention.

The Starship of Theseus

I’m afraid I haven’t done much to make my thesis plausible so far. If anything, I might have made it less plausible! How could linguistic convention, of all things, make a difference to whether the same guy starred in two different movies? Am I saying it’s just linguistic convention, just language, that caused William Shatner to star in The Undiscovered Country instead of, say, Arnold Schwarzenegger? Language doesn’t do that, casting directors do!

Here’s a thought that might help. We can imagine science fiction scenarios where it’s indeterminate who someone is. That is, we can imagine cases in which there’s clearly no fact of the matter about whether someone before us is one person or whether they’re instead a different person. But if there’s no fact of the matter now, in this imagined scenario, then presumably there was no fact of the matter at any point. There were no facts about those kinds of things all along!

Let’s illustrate. Suppose it’s the distant future. You go to see some yet-unmade movie, Star Trek XXIII: The Quest to Retain Intellectual Property Rights with your best friend. A man appears on the screen. Your friend leans in and asks, “Hey, is that Will Shatner?” What I’m claiming is that there are conceivable cases in which there is simply no answer to this question. Not that we don’t know the answer. But that it’s an empty question. Neither “yes” nor “no” will do.

You’re confused. It’ll help if we take a quick detour through the thought experiment called the Ship of Theseus. Imagine a ship. To keep it topical, let’s say it’s a starship. And suppose that starship is made up of exactly one thousand sheets of aluminum. Suppose that one sheet is replaced per year for one thousand years. At the end of the process, the starship doesn’t have a single sheet of aluminum in common with the original. Is it still the Starship of Theseus?

We can complicate the story. Suppose that the sheets of aluminum removed from the original starship are transported to a warehouse somewhere where they’re assembled into an exact replica, so that at the one-thousand-year mark, there are two identical starships: one in the location of the original but composed of none of the same parts, and the other in a different location from the original but composed of all of its original parts.

Which of the two starships is the Starship of Theseus? If it’s the former, what makes it the Starship of Theseus? If it’s the latter, at what point exactly did it become the Starship of Theseus? Much ink has been spilled over this question. It can really make you lose sleep if you take it for granted that there must be a fact of the matter out there in the world that you could discover if only you looked hard enough for it. It’s gotta be in here somewhere! I just need the right lens to see it!

The problem goes away, though, when you realize that you’re barking up the wrong tree. There are no facts about starships out there in the world. There are facts about sheets of aluminum.¹ The name “the Starship of Theseus” is a linguistic convention we use to communicate about certain sheets of aluminum arranged in a certain configuration. And the same can be said about words for all composite entities. They’re ways of communicating about simpler parts in certain configurations.

What does this mean? Well, our concepts for these things are loose enough that they tolerate some change. If I replace one sheet of aluminum from a starship, we’ll clearly want to say it’s still the same starship. But beyond some degree of change, there’s just no answer to whether it’s the same ship. There are facts about which sheets were there at first, facts about which were added later, and facts about their relative positions. Beyond that, there’s just a decision: How do we want to talk about them?

Journey to the Center of the Shimmer

“Okay,” you might be thinking, “That’s fine. I accept that facts about starships are really just facts about the linguistic conventions we use to refer to sheets of aluminum in a certain configuration. But what does this have to do with William Shatner?” And the answer here is: Everything! It has everything to do with William Shatner! The thought experiment we just considered doesn’t apply just to starships or even just to inanimate objects. We can apply the same reasoning to persons!

Here’s a science fiction scenario worthy of Star Trek.² Imagine that, while aboard the Starship of Theseus, William Shatner and his good friend Arnold Schwarzenegger happen upon an unexplained phenomenon. It’s some kind of alien energy field! Let’s call it the Shimmer. Scanners have a hard time penetrating it, but it looks perfectly harmless, so they fly in. Soon they realize in horror what it is, or at least what it does. It’s scrambling all living tissue inside it at the cellular level! 

After a few minutes in the Shimmer, a handful of Arnie’s cells have actually made it into Shatner’s body and vice versa, but at this point, the physiological changes are virtually undetectable. Fifteen minutes in, though, the changes, while still fairly minor, start to be externally visible. Thirty minutes in and each man’s body has unmistakably gained some features of the other’s. By the time they get to the center, half of the original cells of each man will have been replaced with the cells of the other.

Of course, that’s only half the story. As more and more of each man’s brain cells ends up in the other’s skull, they start to observe stranger and stranger transformations in their own mental lives. Gradually, memories of their own experiences will start to fade and be replaced with memories of the other’s. Their character traits, their skills, their driving values and long-term intentions, start to change too. Pretty soon, they’re barely recognizable as themselves anymore both physically and mentally.

It’s easy to miss the point here if you don’t try to get into their shoes. Try to picture things from either of their perspectives. Each one has memories of events undergone by William Shatner. Each one has memories of other events undergone by Arnie Schwarzenegger. In some cases, both men may have memories of one and the same event undergone by just one of the two. For example, maybe each of them has memories of filming The Undiscovered Country.

Here we come back to the beginning. Suppose that one of them later stars in Star Trek XXIII. You go to the premiere. Your friend asks you who’s on the screen. Is he William Shatner? Is he Arnold Schwarzenegger? Is he both? Is he neither? Granted, he sees himself as continuous with William Shatner. But he also sees himself as continuous with Arnold Schwarzenegger. And one person can’t be two people; that doesn’t make any sense! What’s the correct answer here? What should we say?

By asking this, I’ve probably betrayed what I think, namely, that there’s no answer to this question. Just as there are no facts about the Starship of Theseus but only facts about sheets of aluminum, so there are no facts about William Shatner or Arnold Schwarzenegger. There are just facts about physical states, about mental states, and about their causal relations. Beyond that, there’s only a decision about how to use language. The only possible question left is what we want to say.

Giant Bundles of Causally Interrelated States

Let’s see if we can draw some conclusions. What I tried to suggest with the Starship of Theseus is that composite entities don’t exist apart from language. By composite entities here I just mean entities made out of parts. Rocks, sticks, tables, chairs, and cars are all composite entities. Their parts—molecules, atoms, down to subatomic particles and maybe further—are in certain kinds of causal relations. I’m certainly not denying there are facts about those parts and their relations.

What I am denying is that there are facts about the composite entities themselves. Talk about composite entities—about rocks, sticks, tables, chairs, and so on—is really just shorthand for talk about parts in certain relations. And very useful shorthand at that! I’m certainly not suggesting we stop talking about tables and describe reality only in terms of molecules or atoms. “Honey, pass me the 5 × 10²⁴ atoms on top of the 5 × 10²⁷ atoms, please” just doesn’t roll off the tongue very easily.

And the important point is that people are composite entities too. They’re composed of physical states and of mental states. The precise nature of the relation between the physical states and the mental states is a matter of some debate in the philosophy of mind, but it seems clear enough that the mind is in some way causally dependent on the brain. By changing the physical makeup and organization of the brain, it seems, you also change the contents of the mind.

What follows? Well, the linguistic conventions we use to refer to persons—concepts like “the individual,” “the self,” “the ego”; pronouns like “I,” “you,” “he,” and “she”; and names like “William Shatner” and “Arnold Schwarzenegger”—are just useful shorthand for talking about much simpler parts in certain relations. Outside of language, there is no William Shatner and no Arnold Schwarzenegger. There are only physical states and mental states and causal relations.

What we call persons, I’m claiming, are actually loosely defined bundles of causally interrelated physical and mental states. In most cases, of course, these change little enough and gradually enough that it’s useful to treat them as if they were unitary entities. So useful, in fact, that we seem to be evolutionarily programmed to think of them as unitary entities! So we get confused. We suppose there must be some underlying thing, some self, that accounts for their unity. What is it? An immaterial soul? A windowless monad? A transcendental ego?

But this is just the wrong way to go about it. There’s no more need to explain for the unity of the person than there is a need to explain the unity of any other composite entity. The unity of a rock, a stick, a table, or a chair consists in nothing else than its parts being in certain causal relations. And exactly the same thing is true of persons. Or so I claim, anyway.

Hopefully now my thesis makes a bit more sense. There was a bundle of causally interrelated physical and mental states when The Wrath of Khan was released. There was another such bundle when The Undiscovered Country was released a decade later. What makes it true that they’re both William Shatner? Well, just that they’re similar enough and are closely enough related that it’s useful to treat them as one and the same entity. Beyond that, there’s just no fact of the matter.

Conclusion

Hopefully now you can entertain the prospect that you might not exist. Maybe you think it’s rude of me to say so. Nobody likes being told they might not exist. Some people find it very depressing to think that there’s no self or ego—no them!—that persists from moment to moment, day to day, year to year. I confess that I don’t share that impression. Like I said, I think there’s a kind of beauty to it. I’d say it also liberates us from a distressing, though incorrect, understanding of our own death.

However one reacts to the news, though, I think it’s hard to deny that it’s kind of fascinating. For thousands of years, philosophers have suspected that the world as it is in itself, independent of human cognition and convention, must differ significantly from the world of everyday human life. The philosophical enterprise from the Buddha to Plato to Hume can be understood as trying to peel back the veil of distortion and illusion to get at the reality underneath.

What I’m claiming here is that the self is one of those illusions. It is, to borrow Plato’s image, one of the images projected onto the wall of our cave. And what I’m proposing here is that we should climb out. The view outside might be a bit jarring at first, I admit. It might take some getting used to. After all, old illusions die hard. But let’s be honest. Isn’t there also excitement in going where no one—well, except maybe some Buddhists and Humeans—has gone before?³

 

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1. I’m simplifying here for the sake of exposition. You can run exactly the same thought experiment with the sheets of aluminum, breaking it down into molecules, atoms until you reach whatever the most basic constituents of reality happen to be. Those are the only things, it seems, that exist independently of language. ↩︎
2. This thought experiment is adapted from Derek Parfit’s Combined Spectrum thought experiment in Reasons and Persons (1984). Readers who are, like me, huge science fiction nerds will recognize that the Shimmer is borrowed from Alex Garland’s cosmic horror masterpiece Annihilation (2018). ↩︎
3. A huge thank you to Krista Megeney—or rather, to the loosely defined bundle of causally interconnected physical and mental states that we refer to by that name—for her very helpful comments on an early draft of this piece. ↩︎