Time travel and sleep

Some of the commenters on my last post pointed out that time travel itself is not problematic - after all we travel through it, day by day, all the time.  The problem is the discontinuity.  Can one and the same thing 'jump' from one point in time to some future point in time without existing in the time in between?  If so, then since it does not exist at the point just after which it has jumped, and begins to exist again after it has landed.  This seems to violate Locke's maxim.

Some further points to consider.  Dr Who's time actually isn't discontinuous.  He steps into the Tardis, fiddles about with the dashboard and that glass thing that goes up and down, and waits.  Then he opens the door onto a different time, far in the future perhaps.  From his point of view, there is no discontinuity, which only exists from the point of view of someone outside the Tardis.

It's the same with sleep (by which I mean deep sleep).  My consciousness does not exist during sleep. But there is no apparent discontinuity on my side.  I turn out the light, think of sheep, and then the next thing I know there is light underneath the curtains.  Consciousness in its very nature is continuous, and (as I argued in a series of posts around here) it is finite. 

A further problem.  In what sense am 'I' asleep, or unconscious?  If I am my consciousness, and if my consciousness ceases to exist when I am unconscious, how can I be said to be asleep, or unconscious?

Is time travel possible?

Maverick quotes John Locke (great English philosopher and father of the American constitution) on the impossibility of two beginnings of existence, as follows.

When therefore we demand whether anything be the same or no, it refers always to something that existed such a time in such a place, which it was certain, at that instant, was the same with itself, and no other. From whence it follows, that one thing cannot have two beginnings of existence, nor two things one beginning; it being impossible for two things of the same kind to be or exist in the same instant, in the very same place; or one and the same thing in different places.

He infers from this the impossibility of a soul not existing from the death of its body in 1890 (say) to its rebirth in a different body in 1990 (say). Does this also refute the possibility of time travel? Dr Who gets into his trusty police box in 1999 and travels to the year 2101. He lives out the rest of his life in the 22nd century and never travels to the 21st century. Therefore, Dr Who never existed in the 21st century. But he exists at the end of the 20th, and exists again at the beginning of the 22nd. Is this inconsistent with Locke's maxim about the impossibility of two beginnings? It's odd. The maxim seems correct, and it seems impossible that the same thing cannot have two beginnings. It seems almost a logical truth. Yet the impossibility of time travel does not seem a logical truth at all.

Maverick discusses my reincarnation post

Maverick discusses my reincarnation post. He has spotted the obvious problem with my hypothesis that an ego can exist for a certain period, then cease to exist, then exist again, citing an 'authority' in his defence.  It is probably easier to read his (elegant and clear) discussion of the problem rather than for me to attempt a garbled summary.

I am looking for scholastic discussion on what happens to souls while they are waiting for the judgment day, so more later. Meanwhile, here is Scotus' discussion in the Ordinatio II distinction 2 on the question of whether an angel (read: soul) can be in two places at one, and here is the same question discussed in the (probably earlier) Lectura.  Maverick defends a similar idea.

[edit] The first argument is that if an angel (or soul) could be in different places, then it would be distant from itself, just as one place is different from another. This is because two things which are together in respect of some third thing, have to be together themselves, and conversely if they are not together, the third thing they are together with would be distant from itself.  He replies, that the third thing to which the first two are compared is not limited in the respect in which the two things are compared to it, as is clear in the case of the soul in the right hand, and the soul in the left hand. The hands are distant from each other, but the soul is not distant from itself. Likewise, God is not distant from himself, and yet those things which are with God here (i.e. in Oxford), and those things which are with God in Rome, are distant from one another.

I'm not clear about the sense in which my soul is 'in' my hand, nor in the sense that God is 'with' someone in Oxford as well as someone in Rome.  Is it the same as the sense in which this blog post is 'with' Bill in Phoenix, as well as with me here?  And with Anthony, David and the other places where my readers are?

On the logical possibility of reincarnation

Anthony asked what logical possibility is.  I'm not sure, but I think a proposition is logically possible if it does not involve or imply a contradiction.  In that sense, is the proposition "I have been reincarnated" logically possible?  Does it fail to involve or imply any contradiction?

I think it is logically possible. The key assumption is that the term 'I' does not refer to my body alone. For being reincarnated means having once had a body that is numerically different from the one I have now.  I say 'numerically different' because obviously my body was qualitatively different from how it is now.  It used to weigh somewhat less, for example.  So, having a body that was numerically different from the one I have now, means not identical to the body I had in 1980, or 1970.  I don't think there is anything in the reference or meaning of 'I' that entails such an identity.

That's not to countenance disembodied egos or anything like that.  The possibility of reincarnation does not require there to be a disembodied referent for 'I'.  But if there are no disembodied egos, and if reincarnation takes place some time after the death of the previous body, there has to be a time when the 'I' does not exist. E.g. suppose my body used to be Napoleon's body. He died in (er, looks in Wikipedia) 1821.  I was born in 19xx. So if that were the case, my ego would have temporarily ceased to exist in 1821, then was recreated in 19xx.

Does that mean I am the same person as Napoleon, if that were true?  On the assumption that two egos cannot own the same body, then yes. Does reincarnation violate any basic non-logical principles, such as the principle of sufficient reason, or Ockham's principle?  More later.

Consciousness and reincarnation

Anthony objects that where one was born is a matter of biology and circumstance. Well, if it is a necessary or logical truth that the referent of 'I' or 'myself' is identical with my body, then of course. But suppose it isn't – and I can't see any reason why it should be. Suppose, for example, that reincarnation is possible. That means that I, me, myself could be re-born after my bodily death into a different body, and some indeterminate future point in time. Then biology could not explain why I was reborn with that particular body, in that particular place, at that particular time. Obviously biology would explain why that body had the parents it happened to have, and why it had the particular DNA it had. But biology could not explain why I, the person I am referring to now by the personal pronoun 'I', was reborn in that body.

Contra: perhaps it isn't logically possible, on account of the principle of sufficient reason. The principle says that there must always be a reason why something happens one way rather than another. But there is no conceivable reason why I should be reborn in one body rather than another. To be sure, there are religious views about karma that attempt to give reasons for a particular kind of rebirth. But these are hardly scientific, i.e. as far as I know they are not based in unassailable principles known per se and aided by logic.

Reply: But then we are back to the original question: if there is no reason to explain why anyone should be reborn - i.e. born again – in one body rather than another, there is no reason to explain why anyone is born – i.e. born the first time – in one body rather than another. The principle of sufficient reason does not, on its own, establish that reincarnation is logically impossible.

Conscious and the existence of consciousness

I'm beginning to think that my earlier idea that the entire universe had been created this morning was somewhat fanciful and implausible. It was immediately rejected by some commenters, by one of them on the grounds that there has to be a sufficient reason why the world was created this morning (together with a lot of stuff that makes it appear to be much older than one day old, such as dinosaur bones).

OK, but that's a different supposition from the idea that the world always existed, but that my consciousness came into existence this morning.  Here's my puzzle. The world has existed for billions of years, and if consciousness exists at all, there must have been millions or billions of conscious beings.  If my consciousness began to exist in 1955, why then?  Why not in Victorian times?  Why in England?  Why not in the future?  It's completely bizarre, and against the principle of sufficient reason.  And if that principle cannot disprove my consciousness coming to exist in 1955, why should it disprove my coming to exist on 6 June 2012?

Why can't we suppose that my consciousness before this morning was embedded in President Obama, but that all my memories as Obama were wiped out and replaced by 'my' memories?  Perhaps 'my' memories were really Obama's, but they were wiped out and replaced Obama memories when he moved to Obama's body.

This arose out of a conversation with my wife, who was wondering whether reincarnation was a good idea, given that you might be reincarnated as someone who had a tattoo, or a body piercing. I replied that in that case, you would be born with a mindset that liked a tattoo, or a body piercing.  She said that was even worse. I wonder if Maverick has an answer to this, as he usually does.

Consciousness and existence

Sometimes I ponder on the possibility of being born again into a different existence, without any memory (if materialism is correct) of my previous existence in this life here and now.

Then it occurred to me, on waking up this morning, that perhaps this had already happened, and that today was the first day of my conscious existence.  To be sure, I have the recollection of a previous existence in this body, and there is a whole list of posts on this blog that I have been maintaining since 2006.  But that could just be an implanted set of memories.

Perhaps the whole world was created today?  Does anyone here have any evidence otherwise?

Essex on dreaming

Joey Essex (My London, Evening Standard, 27th April 2012) says

I had a nightmare the other day. It felt like I was still asleep but I was awake, but it was weird because I was actually asleep.  When I woke up I was like 'Wow'.  It was so weird.

I'm not sure what he is on about here.  Is the point that, when you are dreaming, you are usually dreaming that you are awake, i.e. dreaming that you are walking, reading, talking to people, doing all the things that you are doing when you are awake. But sometimes you might be dreaming that you are dreaming, or in this case, dreaming that you are awake, but in one of those waking states where it seems as though you might be dreaming.  And then you actually wake up. Weird, eh?

[See also Alarm clock dreams, posted six years ago]

Thought experiment about consciousness

Michael Heap (forensic psychologist and chairman of the Association for Skeptical Enquiry) has sent me the following thought experiment.

You are at the moment taking part in an experiment in which all the activity of your nervous system associated with your conscious experience is being recorded in real time and uploaded onto a computer.  This computer is thus having identical conscious experiences as you - perceptions, thoughts, images, memories, feelings, emotions, pain and so on.   At some point the scientists announce that the experiment is over and they are about turn off the computer.  Do you let them? 

Answers please!

Cantor's Angel

The brief argument I gave here needs expanding. I wrote:

Every day I wake up from sleep, that 'little slice of death', and become
conscious. Imagine the following thought-experiment. I wake up an infinite
number of times. Could I have a conscious moment after that infinite sequence?
Is it possible that there could be a waking moment belonging to my consciousness
such that there are an infinite number of waking moments before that? Surely
not. I can't think of an argument to prove it, rather, it seems an irreducible
part of my idea of consciousness that I cannot conceive of an actual or
'completed' infinity of conscious moments.

Imagine the following thought-experiment. My soul is in hell, and I am being tormented by a demon dentist who is removing my teeth by drilling through their nerves in an exquisitely painful way. My agonising screams are echoing through the halls of the inferno. After all my teeth are removed, they are supernaturally replaced, and the whole process begins again. I understand that this process is to continue infinitely. (There is a colourful depiction of the infinity of hell by James Joyce here).

While I am waiting for the demon to replace my teeth, a Cantorean angel whispers to me. I must not despair. After this process has been repeated infinitely many times, my soul will enter a transfinite Cantorean paradise. I will still be conscious of every one of the infinite moments that has passed in hell. But those moments will now be behind me. They have all happened, infinitely many of them, an infinite number of teeth drilled out and replaced.

Now I ask. Does the pronouncement give me any hope? Surely not. I cannot hope ever to escape this infinite painful process; I have no hope. But if the consciousness in the Cantorean paradise were my consciousness, I would have such a hope. Therefore the consciousness in the Cantorean paradise cannot be my consciousness.

My consciousness is a set of conscious moments tied together by their belonging to a single consciousness. Any future moment must be such that I can hope or expect to experience it by the process of waiting. Thus no future moment of the same consciousness can be such that it is preceded by an infinite number of such moments belonging. For I cannot hope or expect the experience of such a moment. I would be waiting for and expecting something that will never happen to me. (I concede it is logically possible that such a moment could happen to someone else, who was remembering my conscious moments as if they were my own, but more on that later).

Completion and consciousness

Of course the argument I gave yesterday is a blatant fallacy. We have

• Achilles will not reach the tortoise before the sequence is completed
• The sequence is never completed.

but the word 'complete' is being used in different senses in the two propositions, and so the one does not imply the other. In the first sense it means 'happened', and since it seems possible for every event in the infinite sequence to have happened, it is therefore possible for the sequence to be 'complete' in that sense. In the second sense it means something like 'terminated', and in that sense the second proposition seems false. If the sequence were terminated at some point, then Achilles will not reach the tortoise, but we have no argument that it will not be terminated.

But the idea of completion suggests another argument. Every day I wake up from sleep, that 'little slice of death', and become conscious. Imagine the following thought-experiment. I wake up an infinite number of times. Could I have a conscious moment after that infinite sequence? Is it possible that there could be a waking moment belonging to my consciousness such that there are an infinite number of waking moments before that? Surely not. I can't think of an argument to prove it, rather, it seems an irreducible part of my idea of consciousness that I cannot conceive of an actual or 'completed' infinity of conscious moments. (Complete in the first sense of 'already happened').

You object: what if I failed to wake at some point, an infinite number of days passed, and then I woke up? I reply: physical time and conscious time are different. If I go to sleep on Saturday, and an infinite number of days pass, and I wake up, it is no different for me than if I had woken up on Sunday. I cannot conceive of a sequence of infinite waking moments that I can ever 'escape from', in the sense that every one of those moments was behind me. Perhaps there could be some consciousness after such a sequence, but it would not be my consciousness.

Thus any two waking consciousnesses of mine must be connected by a series of finite waking moments. Which leads to the following paradox. Given that every moment of my consciousness is in a sense a waking moment - the only difference being the lapse of physical time which we assume occurs during sleep, and which we assume does not occur when we are waking - and given that any series of conscious moments belong to my consciousness must be finite, how is it that are consciousness also appears continuous. i.e. there are no obvious gaps or 'flickers' in consciousness such as we see in the early movies? How can consciousness be both discrete and continuous?