Indelibility of consciousness

Lowell asked:

What evidence exists for the idea that consciousness is indelible?

Answer by Gershon Velvel

I take it, Lowell, that by ‘indelible’ you mean something like ‘indestructible’. Consciousness, once it exists (and we are not asking how it comes into existence) cannot be wiped out. Although its nature could change in all sorts of ways, some of which we might not be able to imagine.

The evidence is not empirical evidence. It comes from logic. This is a page for philosophy not theology or apologetics. Maybe there’s a God. Or maybe the Devil rules the universe. Or nothing, it makes no difference so far as the logic of the argument is concerned.

The argument proceeds via two ‘lemmas’, or subsidiary proofs.

Lemma 1. Whatever is contingently possible is necessary in infinite time.

It is possible that it will rain tomorrow, and also possible that it will not rain tomorrow. Is it also possible that it will never rain again, anywhere on Earth or indeed anywhere else in the Universe? Why not? Maybe the day after tomorrow the Universe will be wiped out of existence and therefore there will be no more rain, anywhere, ever.

But now we have to deal with the tricky question of infinity. Never say ‘never’. ‘Never’ refers to infinite future time, and I’m not sure that either you or I really grasp what that means. The Universe could have gone out of existence for a very, very long time (pick a number, any number) but it is always possible that another Universe will come into existence, and that there will be rain, on some planet in some solar system in some galaxy in that Universe.

You might think that this falls short of showing that rain must occur at some time in the far future. When in geometry one says that, ‘parallel lines meet at infinity’ that doesn’t mean that the lines actually meet. It’s more like a convention. But our claim does not rely on an analogy with geometry.

Nor is it like mathematics where (as Wittgenstein once remarked) as yet there is no proof or disproof that a sequence of four 7s occurs in the expansion of Pi. A disproof could yet appear, in which case we would know, as well as we know the truth of any arithmetical statement, that it does not. But this is something we might never be able to ascertain, either way. Given our present state of ignorance, no-one can say now that four 7s ‘must’ appear somewhere in the expansion of Pi.

Rain, by contrast, is a contingent phenomenon. It is not, like the expansion of Pi, the product of some necessary rule. In the absence of any mathematical or logical rule that would restrict what is or is not ‘really possible’, all contingent phenomena must be realized in infinite future time. If, in infinite future time, it can rain again then it must rain again.

Lemma 2. The identity of consciousness is not dependent, in whole or in part, on spatio-temporal continuity.

This is a claim that would be strongly contested by any philosopher of a materialist persuasion. The objection isn’t just the implication that consciousness is not constituted from matter. That would be to beg the question. Rather, the problem concerns the definition of identity, or what it is for some entity, identified at time t1 to be ‘one and the same’ as an entity identified at a later time t2.

Let’s say that while visiting your house I carelessly knock over a precious vase, bequeathed to you by your grandmother. ‘I know a shop where I can find exactly the same vase,’ I say. ‘It won’t be the same vase because it won’t be the one my grandmother bought back from her trip to Brighton in 1955.’ There’s no answer to that, except for me to get out the Araldite and laboriously stick the pieces back together.

After the universe has come to an end and another universe has come into existence, there is nothing, in logic, that could count as the vase in question ‘coming back’. Maybe there will be another Brighton just like Brighton on the South coast of England, etc. but the vase that comes from there won’t be one and the same vase. That possibility is ruled out by the definition of identity in terms of spatio-temporal continuity.

But now let’s suppose that the Bomb drops. The last thing you remember as you looked out of the window of your apartment, is a blinding white flash and the agonizing sensation of your flesh being burned off your bones. And now, here you are, awake and intact, in a place you’ve never seen before. You are alive. Maybe this is Heaven, or Hell, or just some planet in some Universe far, far in the future.

Materialists will come back at this saying there is no way on this picture to distinguish between ‘true’ and ‘false’ memories. Which is true. But it is also true that nothing can override your subjective certainty that you have, indeed, survived a direct hit by an atomic bomb. You know that you are you, just as surely as you know this every time you wake up in the morning. Run through the thought experiment a few times, if you are not sure, until you are convinced.

To prove: consciousness is indelible.

From Lemma 2, we know that consciousness — that is to say, you — can always come back at some time in the future. From Lemma 1, we know that if you can come back you will come back. Therefore, you can never we wiped out permanently. Your consciousness is indelible. Q.E.D.