Why Does the World Exist?: An Existential Detective Story

by Jim Holt

  If you think that the answer to the last question is “yes,” consider the following scenario. You are informed that you are going to be tortured tomorrow. Understandably, this makes you fearful. But prior to the torture, you are told, your memories will be wiped out by the fiendish neurosurgeon and replaced with my memories. Would you still have reason to fear the torture? If you did, it would mean that, despite your complete psychological makeover as me, it would still be you who endured the pain.

  Such a thought experiment was proposed in 1970 by the philosopher Bernard Williams to show that the psychological criterion of personal identity must be mistaken. But if psychological factors don’t determine my self-identity, what could? The obvious alternative—endorsed by Williams and later, more tentatively, by Thomas Nagel—is the physical criterion. My identity as a self is determined by my body; or, more specifically, by my brain, the physical object that is causally responsible for the existence and continuity of my consciousness. On the “I am my brain” view, the actual contents of your stream of consciousness don’t matter to your identity. What is all-important is the particular blob of gray meat that is lodged in your skull. You cannot survive the destruction of this blob. Your self could not be “uploaded” into a computer, nor could it be resurrected in some ethereal form. Nagel has gone so far as to suggest that even if an exact physical replica of your brain were created, and then stocked with your memories and lodged in a clone of your body, the result would still not be you. (Although it would certainly think it was you.)

  So when I say “I exist,” I may just be asserting the existence of a particular (functioning!) brain. Then the question Why do I exist? has a purely physical answer: I exist because, at a certain moment in the history of the universe, a certain bunch of atoms happened to come together in a certain way.

  The problem with this easy answer, as Derek Parfit has pointed out, is that even the physical identity of my brain is not an all-or-nothing affair. Suppose, Parfit says, all of your brain cells have some defect that would eventually be fatal. Suppose further that a surgeon could replace these brain cells with duplicates that were not defective. The surgeon might do this gradually, in a series of, say, a hundred cell-grafting operations. After the first operation, 99 percent of your original brain would remain. In the middle of the series, half of your brain would consist of original cells and half of duplicates. And just before the final operation, your brain would be a 99 percent replica. Would the self at the end of this series of operations still be you, even though your original brain had been completely destroyed and replaced? And if it ceased to be you, at what point in the series did you suddenly disappear and get replaced by a new self?

  It looks as if neither the psychological criterion nor the physical criterion decisively settles who I am. This raises a disturbing suspicion. Perhaps there is no fact of the matter when it comes to my identity. Perhaps there is no real answer to the question of whether I exist or not. Even though I am referring to something when I say “I” or “me,” that something has no ontic solidity. It does not figure among the True and Ultimate Furniture of the Universe. It has no existence apart from the constantly shifting mental states that populate my mind and the constantly changing set of physical particles that constitute my body. The self is, to use Hume’s analogy, like a nation; or, to use Parfit’s analogy, like a club. We can keep track of its identity from moment to moment. But the question of whether it remains the same over long stretches of time, or through great physical and psychological discontinuities, is an indeterminate, even an empty one. The enduring, substantial, self-identical I is a fiction. As the Buddha put it, the self is “only a conventional name given to a set of elements.”

  Hume found this conclusion, convinced though he was of its truth, to be a depressing one. It left him, he wrote, “in the most deplorable condition imaginable, inviron’d with the deepest darkness.” (Fortunately, he was able to find relief by playing backgammon with friends.) By contrast, Derek Parfit, rather more like the Buddha, finds it “liberating and consoling.” Before, when Parfit thought that the existence of his self was a deep all-or-nothing fact, “My life seemed like a glass tunnel, through which I was moving faster every year, and at the end of which there was darkness.” Once liberated from the self, however, “the walls of my glass tunnel disappeared. I now live in the open air.”

  Suppose that the Cartesian I—the I of “I think, therefore I am”—truly is an illusion. How could such an illusion arise? (And, one might want to ask, for whom or what is it an illusion?) Well, to be an I is to have self-consciousness, to enjoy the power of reflexive awareness. So perhaps the I is conjured into existence in the very act of thinking about itself. Perhaps, in other words, the I is self-creating!

  Such was the daring hypothesis that Robert Nozick put forward, albeit “with great hesitation,” to deal with the otherwise “quite intractable” problem of the source of the self. According to Nozick, when the Cartesian says, “I think,” he is not referring to any preexisting entity. Nor is he truly describing an already existing state of affairs. Rather, the state of affairs is made true by the declaration. The entity referred to by the pronoun “I” is (somehow) delineated in the very act of self-reference, which picks out “the thing of greatest organic unity” that includes the act itself. And what are the boundaries of this organically unified self-creation? “Nothing we have said thus far limits what the self-synthesizing self can synthesize itself as,” Nozick observed. He even entertains the possibility that this self might be “identical with the underlying substance of the universe, as in the Vedanta theories that Atman is Brahman.”

  Once you entertain the notion that the I is self-creating, it’s easy to find yourself sliding down a slippery transcendental slope. And what lies at the bottom of that slope is a curious form of idealism, one which says that the I, in creating itself, creates all of reality. Daft as this notion might sound, it crops up repeatedly in European philosophy after the time of Kant. Versions of it can be found in Hegel, Fichte, and Schelling in the nineteenth century, and in Husserl and Sartre in the twentieth century.

  Take Johann Gottlieb Fichte, the son of an impoverished ribbon-weaver who grew up to become not only the esteemed philosophical successor to Kant but also the intellectual father of German nationalism. Fichte held (like Nozick) that the I leaps into existence in the very act of “positing” itself. The statement “I = I,” being an instance of the logical law of identity, is a necessary truth. Indeed, according to Fichte, it is the only necessary truth, because it presupposes nothing. (Ordinarily, the truth of the identity “A = A” presupposes existence of A. But the existence of the I in “I = I” is guaranteed by the self-positing nature of the self.) As the sole necessary truth, “I = I” must be the ground of all other knowledge. Therefore, Fichte thought, all knowledge must ultimately be self-knowledge. The transcendental subject not only creates itself in the act of positing, but also creates the world—a true ontological tour de force! “All art, religion, science and institutions are gathered into this process, expressing some part of the great spiritual journey, whereby the empty I = I takes on flesh, so as to know itself at last as an ordered and objective reality, and also free,” as the contemporary philosopher Roger Scruton described Fichte’s miraculous world-engendering dialectic.

  Edmund Husserl, founder of the phenomenological movement in the early twentieth century, endowed the I with similar ontic powers. “The objective world,” Husserl submitted, “derives its whole sense, and its existential status . . . from me myself, from me as the transcendental Ego.”

  Now, for me to believe that I am literally the fountainhead of all reality would be metaphysical hubris, if not insanity. Yet whatever my self really is—a substance, a bundle, a locus, a receptacle, a vehicle, a self-writing poem, a grammatical shadow, a transcendental Ego—it does seem to stand at the center of the world. “The world is my world,” Wittgenstein declared in proposition 5.62 of the Tractatus. And he strengthened the point in prop
osition 5.63: “I am my world. (The microcosm.)”

  Of course, the world could be my world—as opposed to your world, or her world—only if I am the sole genuine self: the Metaphysical Self. Not being a solipsist, I don’t believe this. (Although, as a child, I believed I could make the world go dark by closing my eyes.) Even though I am at the center of my subjective world, I believe there is an objective world, one which exists quite independently of me, a vast expanse of space and time that I know a relatively tiny portion of. This objective world was there before I was born, and it will continue to be there after I die. I also believe that the objective world is centerless. It has no built-in perspective—the way it would, say, if it existed in the mind of God. And it is as centerless that I must try to understand the world.

  Thomas Nagel has memorably dubbed this centerless view of reality “the view from nowhere.” And the self that strives to take this view of reality he calls the “objective” or the “true” self. The objective self, on Nagel’s account, is something different from a particular person. This self treats the experiences of that particular person as a sort of window onto the world, using those experiences to construct a perspectiveless conception of reality. But, having done this, the objective self is confronted with a startling puzzlement: “How can I, who am thinking about the entire, centerless universe, be anything so specific as this: this measly, gratuitous creature existing in a tiny morsel of spacetime, with a definite and by no means universal mental and physical organization? How can I be anything so small and concrete and specific?”

  When he considers the world objectively, Nagel is astonished that his consciousness should be localized in a particular human being. “What kind of a fact is it,” he asks, “that I am Thomas Nagel?” It seems to him miraculous that he, this fleeting organic bubble in the ocean of reality, should be “the world soul in humble disguise.” Lest this sound like metaphysical megalomania, Nagel pleads in extenuation that “the same thought is available to any of you. You are all subjects of the centerless universe, and mere human or Martian identity should seem to you arbitrary. I am not saying that I individually am the subject of the universe: just that I am a subject that can have a conception of the centerless universe in which TN is an insignificant speck, who might easily never have existed at all.”

  Philosophers who would like to deflate Nagel’s “objective self” argue that the sentence “I am TN” is true if and only if it is uttered by TN, and that there is nothing more to it, startling or otherwise, than that. It’s no different from the sentence “Today is Tuesday,” which is true if and only if it’s uttered on Tuesday. But Nagel counters that such an impersonal semantic analysis leaves a gap in our conception of the world. Even when all the public information about the human being TN has been included in the objective conception, he says, “the additional thought that TN is me seems clearly to have further content. And it is important that the content is startling.”

  (At lunchtime, after typing the preceding words, I went around the corner to the local gourmet market in Greenwich Village to get a chicken-and-avocado sandwich. And there, standing unobtrusively in the checkout line with a basket of groceries, was Thomas Nagel himself—the world soul in humble disguise. I nodded to him, and he nodded back amiably.)

  Do I feel similarly startled that I am JH? It depends on my mood. Sometimes the thought strikes me as deeply mysterious. Sometimes it strikes me as perfectly vacuous. (In that respect, it’s a little like the thought that there is Something rather than Nothing.) Unlike Nagel, I don’t feel particularly surprised when I ponder my cosmic unimportance. I don’t have any difficulty seeing myself as an “insignificant speck.”

  Could I have been someone else other than JH—some quite different speck? Suppose the history of the world had gone just as it actually has, only I was Napoléon and Napoléon was me. What happens when I try to conceive of such a possibility? Well, I might imagine myself as being short of stature and wearing a cockaded hat, my hand thrust into my tunic, viewing the devastated battlefield of Austerlitz. But, as the philosopher Bernard Williams shrewdly pointed out, all I have really imagined here is play-acting at being Napoléon. This no more enables me to understand how I could have been Napoléon than seeing Charles Boyer play Napoléon on the screen enables me to understand how he could have been Napoléon.

  If I say to myself, “I might have been Napoléon,” the pronoun “I” cannot very well refer to the empirical JH, the one who led a quiet and harmless existence on the North American continent in the late twentieth and early twenty-first centuries. For in that case, the proposition would be a straight contradiction. So the “I” here must refer to my self as it would be if it were stripped of all its physical and psychological baggage—to my pure, timeless, featureless Cartesian ego. That is the self that I am trying to imagine switching with Napoléon. But do I have such a self? Do you?

  If you do, then that opens up possibilities even more vertiginous than switching selves with Napoléon. For instance, you might (as Derek Parfit has observed) suddenly cease to exist in the middle of reading this paragraph, and be replaced by a new self that would inhabit your body and assume your precise psychological makeup. If such a thing happened, there would never be any external evidence of it.

  Another possibility is that the world could be exactly as it is, except that your pure Cartesian ego never existed at all. Your empirical person, with its genetic identity, memories, social relations, and all the rest of its life history would still be there. Only it would not be you. It would be your (perfectly) identical twin. The little light of your consciousness would never have flickered in the world.

  It is hard to find a philosopher these days who takes seriously the idea of such a pure Cartesian self. Parfit deems it “unintelligible,” and Nagel, despite his talk of the “objective self,” gives no indication that he thinks such a self can be wholly detached from its physical and psychological moorings. (Indeed, if the brain is the core of the self, as Nagel tentatively believes, then even transplanting my brain into Napoléon’s body would leave me stuck with being just a shorter and sallower JH.) And if the self could be so detached, Williams asked, what would be left to distinguish one pure Cartesian ego from another? What exactly would be subtracted from the world by the removal of me?

  “AMAZEMENT THAT THE universe should have come to contain a being with the unique property of being me is a very primitive feeling,” Nagel observes. Like him, I cannot help feeling somewhat astonished that I exist—that the universe has come to produce these very thoughts now bubbling up in my stream of consciousness.

  Yet the astonishment I feel at my improbable existence has a curious counterpoint: the difficulty I have in imagining my sheer nonexistence. Why is it so hard to conceive of a world without me, a world in which I never put in an appearance? I know, after all, that I am hardly a necessary feature of reality. Still, like Wittgenstein, I can’t think about the world without thinking of it as my world. Although I am part of reality, reality feels like a part of me. I am its hub, its epicenter, the sun that illumines it, the baby to its bathwater. To imagine that I never existed would be like imagining that the world never existed—that there was Nothing rather than Something.

  The feeling that the “something-ness” of reality depends on my existence is, I know, a solipsistic illusion. Yet even when it is recognized as such, it retains a considerable grip. How can I loosen its grip? Perhaps by holding steadily before me the thought that the world got on quite happily for many eons prior to that unlikely moment when I was abruptly awakened to life out of the night of unconsciousness, and that it will get on quite happily after the inevitable moment to come when I return to that night.

  15

  RETURN TO NOTHINGNESS

  A man finds himself, to his great astonishment, suddenly existing, after thousands of years of non-existence; he lives for a little while; and then, again, comes an equally long period when he must exist no more. The heart rebels against this, and feels that it
cannot be true.

  —ARTHUR SCHOPENHAUER, “The Vanity of Existence”

  Although my birth was contingent, my death is necessary. Of that I am reasonably sure. Yet I find my death difficult to imagine. And here I am in impressive company. Freud said he could not conceive of his own death. So did Goethe before him. “It is entirely impossible for a thinking being to think of its own non-existence, of the termination of its thinking and life,” Goethe said, adding that “to this extent, everybody carries within himself, and quite involuntarily at that, the proof of his own immortality.”

  Such a “proof” of immortality is, alas, quite worthless. It is another instance of what has been called the philosopher’s fallacy: mistaking a failure of imagination for an insight into reality. Not everyone, moreover, finds his own death inconceivable. Lucretius argued, in the stately verse of De Rerum Natura, that it is no harder to imagine not existing after one’s death than it is to imagine not existing prior to one’s birth. David Hume evidently felt the same way. Indeed, he claimed to find posthumous nonexistence no more frightening than prenatal nonexistence. When asked by James Boswell whether the thought of annihilation terrified him, Hume calmly replied, “Not the least.”

  To exhibit such sangfroid in the face of death is said to be “philosophical.” To philosophize, Cicero declared, is to learn how to die. Here Socrates is held to be the model. Sentenced to die by an Athenian court on the charge of impiety, Socrates serenely and willingly drank the fatal cup of hemlock. Death, he told his friends, might be annihilation, in which case it is like a long, dreamless slumber; or it might be a migration of the soul from one place to another. Either way, it is nothing to be feared.

  Why should the prospect of annihilation disturb me, if it did not disturb Socrates or Hume? I have already said that I cannot easily imagine my own death. That might make death seem a mysterious and therefore fearful thing. But I cannot imagine my being totally unconscious either, yet I enter that state every night, and quite fearlessly.