W Harwood, harwood.will@gmail.com
March, 2024. Book coming, possibly
We have a single idea: that we can take a materialist view of life, one in which we live and then die and there is nothing before and nothing afterwards; one that believes in oblivion; one in which the usual consolation for the fear of death is, "when death is, I am not"; and precisely by taking this view seriously argue ourselves into a radically different position. Our motivation is the question: "What is it like to be dead?" It is, to a non-theistic materialist, a nonsensical question. Death is oblivion, and that is unimaginable. To imagine a thing is to put yourself next to it, but there is no you to put anywhere. And yet, we can find a perfectly explicable and easily understood answer, mere steps away. It is the same answer as that of the question, "What was it like to not yet be alive?" There is no oblivion after all.
Let's call the "standard, materialistic, physicalist, non-theistic view of life" the common-sense view. There is nothing but the physical world. We exist for a span of time, ninety years or more if we are lucky, and then we die, and that is that. It is common sense because we see that the body does not last forever so why should our consciousness, so manifestly supported by the body, continue to exist after the body has ceased to function? We are exactly our physical bodies, there is no ghost in the machine. We are special arrangements of matter; so special that we can think and feel and somewhat know ourselves, as partial and temporary perspectives on the universe.
Notice that we have already conflated life and consciousness. Most living things are never conscious. There are no conscious plants (what use is consciousness to a plant?); and no creature is continuously conscious, including ourselves. It is a semi-official tenet of the common-sense view that there is no reason in principle why a computer might not become conscious---which is not the same as the question of whether a computer could become intelligent, though as with life and consciousness, consciousness and intelligence are frequently conflated.
Consciousness is what counts. In the common sense view, consciousness is a fact of the physical universe, the Hard Question we might never answer. It is simply true that certain very rare arrangements of matter are conscious and other arrangements are not.
We say, "no creature is continuously conscious", but we should clarify this to mean: to an observer, no creature is continuously conscious. Because what is the subjective experience of that creature (say, you)? It is to be continuously conscious, simply because, of course, we do not experience unconsciousness. Dreamless sleep, like general anaesthetic, passes immediately. Subjectively, we are always conscious, an unbroken line from our first (conscious) moment to our last.
The problem of death is the problem of non-existence. "Death is nothing to us," said Epicurus, who died two thousand three hundred years ago. "When we are, death is not; and when death is, we are not." It is an idea that makes the common-sense view bearable. Death as an absence. There is no experience as there is nothing to have the experience. Yet that gives, in Larkin's words, "a special way of being afraid". Because it is terrifying to contemplate. Not that something bad will happen to you after you die; not even that nothing will happen to you. But that there is no you. Metaphors betray us: to say that you will leave the world suggests that you will go somewhere else, but there is no you, and no leaving, as to leave is a verb and verbs require a subject.
This is not an obscure problem. The Roman philospher Lucretius, a later follower of Epicurus, put an argument into verse on why we should not be afraid:
Look back---think how little you care
For the endless ages of time
That passed, unknown, before your birth.
Nature holds a mirror for you
In which that time is reflected
And welcomes the infinity
That will come after you have died.
Why fret? Where is the tragedy?
Death is a greater peace than sleep.
You did not exist 100 years ago, and it has never bothered you. You will not exist 100 years in the future, and that bothers you greatly. But do you see the symmetry, that two situations are the same?
This book is motivated by the problem of what it is like to be dead. The common sense view leaves us with something unimaginable: oblivion, no thoughts or feelings as nothing exists to think or feel. Lucretius attempts to assuage our anxiety about this fact by pointing out that we have been there before. Non-existence is non-existence, whether in the past or the future. It contains a subtle contradiction though. Because in fact we have not been there before. We did not exist in the distant past, we were not there in any sense. In the past, we never existed; in the future, we will have existed. Time's Arrow, not grammatical pedantry. What was it like to not exist in the past? We know the answer to that: it was like immediately becoming conscious in the present. That is what it was like. Time begins with us.
Imagine a person who will be born in a trillion years. What is it like for them now, in the present, on the other side of Lucretius' mirror? It is not glib but merely true to say that what it is like is a trillion years immediately passes. The question, "what is it like to not yet be conscious" is readily answerable: immediate consciousness. It is the other side, "what is it like to never again be conscious" that is hard. It is our question to answer.
Lucretius gives us two questions:
To him, both questions are the same question and have the same answer: oblivion. We have already argued that the first question has a quite different answer though. What was it like? Not oblivion, but immediate consciousness. What if that were the answer to the second question too? What if they have the same answer after all, only it is not the oblivion that the common-sense view assumes?
Almost five hundred years ago, in his own copy of Lucretius, Michel de Montaigne noted:
As there are varied movements of atoms, it is not incredible that once upon a time atoms came together, or will come together again, so that another Montaigne is born.
It is an astonishing comment for the age, and offers the first answer to our question. In the common-sense view, there is just matter and its arrangement, no extra super-natural substance. If a person is a certain arrangement of matter, and that person dies, then given enough time, or a large enough universe, then purely by chance that pattern of matter will inevitably reappear. Perhaps immediately, perhaps after many trillions of years. And if not trillions of years then quadrillions, quintillions: eventually. And if it is inevitable that whatever pattern that makes the person will reform, then in that moment the person returns. And we have our answer: not existing in the future is the same as not existing in the past. In both cases, what it is like is: you are immediately conscious.
This is what it is like to be dead: you are not dead any more.
An objection: why should the future be infinite? And even if infinite, why should patterns continue to form? Space is expanding, the universe thins and cools, everything is moving away from everything else. Picture a little host of particles coming together to make a shape, then flying off in different directions, forever. The longer we wait, the further away that pattern will be.
In three billion years there will be nothing alive on Earth. In 100 trillion years the last sun will be born. Spin forward far enough and only black holes will exist; further, and even they will fizz away. Wait longer, fabulously longer, and according to at least one theory of quantum mechanics, a new Big Bang will spontaneously occur.
And if not? If the ultimate fate of the universe is an eternal Heat Death, in which all is the same temperature and no work (in the technical sense) can be done; in which nothing can happen and life is impossible, as life spends entropy and there is no entropy left. Even then, look closer. Temperature is a statistical fact, an average. Subatomic particles seathe and rearrange themselves even in a dead universe. Given enough time, any pattern will---very briefly---appear. Ludwig Boltzmann, some hundred and thirty years ago, proposed that our observable universe could have lurched into existence as a statistical quirk. Shuffle a deck of cards for long enough and you will shuffle it into its original order; whisk an egg for long enough and you could reform the yolk.
This idea was later lampooned as the "Boltzmann Brain": that, far more likely than the whole universe appearing on the flip of a coin, is that a single brain appears, with enough time to have a single thought (the thought you are thinking right now), before it falls apart, utterly untenable that its existence is. (As a mildly terrifying thought experiment, consider that if the Heat Death is the fate of our universe, then over its history there are vastly more Bolzmann Brains than real brains, each with time for a single thought or feeling before death. By basic probability, you are more likely to be a Boltzmann Brain at the end of the universe than a human brain at its start.)
For our purposes it does not matter whether the future is an endless succession of Big Bangs, or an eternal void in which every ten-to-the-ten-to-the-fifty years or so a Boltzmann Brain appears, imagines it is reading a book, then dies. We just need something rather than nothing, and we need it forever.
A more challenging objection: my twin is not me. Derek Parfit thoroughly explored this question---and did so by taking the transporters of Star Trek seriously. If I were transported as a beam of information to Mars, and reconstituted of new atoms there, would I be me, or merely a person who thinks he is me? Would my subjective experience be: thinking and feeling on Earth, standing on the transporter pad, then thinking and feeling on Mars; or would it be: thinking and feeling on Earth, standing on the transporter pad, then oblivion; while another entity has its own thoughts and feelings on Mars? Would the subjective line begun on Earth continue on Mars, or would it break, and a new line start there?
Imagine the line does break, that the transported me is not me, that it is not a mode of transport but of death. Why might that be?
Here we can say: there are people who have died and then been revived. Or consider: you are an astronaut, and after some catastrophe you are suddenly cooled to minus 270 degrees. You are certainly not alive. The freezing is so sudden though that when, 100 years later, your body is recovered, it is possible to reheat you with minimal damage, and bring you back to life. What would your subjective experience be? It is not difficult to believe that it is you who is revived, not merely someone who thinks they are you.
We will argue more on this later. As a sticking-plaster refutation let us ask: are the atoms different? Take two electrons. There is no means to tell them apart. All subatomic particles are, by any measure, identical.
Consider two versions of a vacation to Mars. In one, I take a rocketship; in another, I am beamed there by a transporter. Imagine that the transporter is arranged in such a way that the version of me reconstructed on Mars is identical to my state after taking a rocketship. I.e. in both situations the start and the end are identical, only the means in between differ. What happens to my subjective line in each?
In the first case, I am on Earth, I fly through space, I arrive on Mars. The me on Earth is clearly the me on Mars. There is a single, unbroken subjective line. In the second case, I am on Earth, I am transported, then an exact copy of me materialises on Mars.
Earth Mars
@ @ @
By rocketship /|\ --> /|\ --> /|\
|\ | /|
= != =
@ ### @
By transporter /|\ --> ### --> /|\
|\ ### /|
What happens to my subjective line? It is no longer certain that the me at the start is the me at the end. We consider two possibilities. In one, my subjective experience is: I am on Earth, I am dematerialized and cease to exist, then my subjective experience resumes on Mars. It does so immediately; my subjective line has no gaps. The second possibility is I am on Earth, I am dematerialized, and then: oblivion. Meanwhile, someone identical to me, who certainly believes that they are me, appears on Mars. Theirs is a new subjective line.
@ ### @
Possibility 1: /|\ --> ### --> /|\ -->
One subjective line |\ ### /|
@ ###
Possibility 2: /|\ --> ### @
Two subjective lines |\ ### /|\ -->
/|
To follow the logic of the common-sense view is to reject the second possibility. Whether I go to Mars by rocketship or transporter---whether I am composed of the same atoms or new ones---makes no difference to my subjective experience. To see why, imagine the converse, and try for a contradiction.
Remember, we have said that the two versions of me---one having arrived on Mars via a rocketship, the other by transporter---are identical. No physical test can tell them apart, even at the atomic level. But we have also argued that they are different: one's subjective line goes back to Earth, the other's began on Mars. One is me, the other is someone new, who is merely identical to me. Where is the difference kept?
In the common-sense view, there is only the physical world, and physically the two versions of me are identical. They cannot be both different (one me, the other a being who merely thinks he is me), and identical (in the sense that no physical test can tell them apart).
An objection: the two identical versions of me on Mars are, of course, different. One travelled there by rocketship, the other was transported there as a beam of information. They have different pasts, even if they are physically indistinguishable in the present. Why does the same logic not follow for whether one is and the other is not the continuation of my subjective line?
We lean on the common-sense view, and common-sensical assumptions on our continuity of consciousness, and say: in the past, the two bodies were different, the historical difference was represented by a physical difference (one body carried through space, the other beamed through it); consciousness though is a difference happening now. It is not a historical fact but a present one. Either I am or I am not conscious. That is a difference in the present, and so by our physicalist assumptions, must be reflected somehow in the present physical state too.
We come to the conclusion that either the common-sense view is wrong, or matter does not matter. That it is the pattern that counts, and even if you were turned to information and reconstituted two hundred million kilometres away, it would still be you, and you in the sense that your real, subjective experience of being beamed to Mars is not oblivion, but waking up on Mars.
We began with the common-sense view. A physicalist, un-supernatural set of assumptions of what existence is. There are mysteries, to be sure. How can certain arrangements of atoms think and feel? And there is an assumption that our conscious life is finite, that our subjective experience ends and nothing follows it. We have probed this idea by considering two questions: what is it like to not yet be alive, and what is it like to be dead. Or rather: what is it like to not yet be conscious, and what is it like to never again be conscious. It is easy to answer the first question. What it is like is that you are immediately conscious. After all, there is no like until you are conscious, and no sense of time until you are conscious. To the second question, the inspiration of "vast most-eaten musical brocades", we groped towards an answer. What if the question itself is ill-formed? What if there is always a future in which you are conscious? That it will never be true that you will never again be conscious? If that were so, then the two questions collapse into one. What is it like to be dead? You are conscious again. We used the common-sense view to justify, or at least make plausible, our hypothesis. We argued that the pattern and only the pattern is important, and that any pattern will inevitably recur.
This is subjective immortality: one experience after another, forever.
We equate a person's consciousness with a physical pattern. But consciousness is, fundamentally, a phenomenon of change. To perceive a thing is to change and be changed by it.
In the Vacations to Mars thought experiment, we need the two versions of me---the one who came by rocketship, the other who was beamed to Mars---to be identical for the argument to work. We claim that since one version (who came by rocketship) undoubtedly continues my subjective line, the other (beamed by science fiction) must do so too, otherwise they could not be physically identical.
What, though, is this "subjective line", or "subjective continuity"? You are conscious in this moment; in the following moment you are also conscious. You anticipate future pleasures and pains because you believe that it will be you experiencing them. Belief is too weak a word here: personal continuity is fundamental to the workings of our intelligence. We plan for we are planning for ourselves.
Yet what, exactly, is being carried forward? If we remove the supernatural, we are left with atoms in patterns that change one moment to the next, and must change if any experience is to be had.
There are two useful analogies for subjective continuity and its opposite:
By nature, we see ourselves on the road, taking steps into the future. The common-sense view forces us to think in terms of the ship. The future is not a dimension we travel into; it is change that creates the future.
David Hume writes:
[W]hen I enter most intimately into what I call myself,
I always stumble on some particular perception or other,
of heat or cold, light or shade, love or hatred, pain
or pleasure. I never can catch myself at any time without
a perception, and never can observe any thing but the
perception. When my perceptions are removed for any time,
as by sound sleep; so long am I insensible of myself,
and may truly be said not to exist.
In Reasons and Persons, Parfit builds a moral edifice from Hume's bundle theory of identity. Consider that we are nothing but bundles of impressions, with no unchanging core. You are just as different from a future version of yourself as you are from the present version of someone else, and have the same moral obligation to them. This raises the disturbing idea that not only might there not be subjective immortality, there might not even be subjective continuity. You might not be you one minute to the next. While you are here right now, it could be some different person looking out of your eyes next week.
(Perhaps this should not be so surprising. Over short timeframes we certainly believe in subjective continuity; over longer timeframes that is less clear. Which young person really believes that they will become old?)
Or, There is no such thing as the subjective line. A thorough contradiction of A note on continuity, above.
The common-sense view brings us to two plausible conclusions:
So we have either transience or immortality. Either there is just one experience, or if there is more than one experience, there is no justification for there not being an infinite number. While we come round to subjective immortality again, it is no longer as a form of personal continuity. Experience is, and we are not separate from it.
We are the part of the universe that is experience---whatever, wherever and whenever that happens to be.