As an aside one can of course concede that the neuroscientific data does indeed constitute strong evidence that brains produce consciousness. However this fact is blunted somewhat when we consider various alternative evidence. For example, near-death experiences and the closely related phenomenon deathbed visions, crisis apparitions, and so on. Moreover it can be argued that ESP at least indirectly suggests that we survive the death of our bodies. In contradistinction to the brain produces consciousness hypothesis, this alternative evidence with its implication of a "life after death" has the not inconsiderable bonus of being consistent with our intuitive conviction that we are persisting selves. I have previously written about this here (in contrast naturalism/materialism is simply incompatible with the notion of a persisting self. This will be attempted to be made clear below in the context of the replication/teleportation thought experiment). What for the sake of simplicity I didn't mention in my paper is that I also consider the notion that brains produce consciousness to be deeply philosophically problematic (each of the various positions eg reductive materialism, non-reductive materialism, strong emergence, seem to be untenable for differing reasons). However I don't want to address these deep philosophical problems here -- that can be deferred to when Keith's book is published and I write my review of it.
What I intend to do in this blog entry is to put aside my own beliefs and accept for the sake of argument that brains do indeed produce consciousness. At first blush, even if this were a fact, it cannot rule out a "life after death". I'm primarily thinking here of resurrection, or uploading our consciousness into a robot or some other artificial body. Even the prospect of reincarnation does not seem to be ruled out so long as we understand it need not be a "soul" that survives in order to conclude that reincarnation might be meaningfully be said to have occurred.
However Gualtiero Piccinini disputes this, and he does so by a thought experiment involving the teleportation and replication of individuals. In his paper he argues:
" imagine that teleportation is invented. A teleporter disintegrates your current body, extracts precise information about the location of each particle that constitutes you, and makes an exact particle-by-particle replica of you in another location. To go from New York to Paris, says the advertisement, you can take a plane, which takes seven hours and costs $1,000, or take the teleporter, which takes only a minute and costs $100. Which one would you take? If you are in doubt, consider a more advanced teleporter. It makes a copy of your body by scanning your present body without destroying it. Now it should be pretty clear that after you enter and exit the teleporter in New York, you are the person who is still in New York, while the new body in Paris is a mere replica distinct from you. Regardless of how many replicas are made and whether making replicas requires the destruction of your current body, your replica is not you. No one can make your replica numerically identical with you—not even god (contra Baker 2011)".
But let's press this further. The replica will look the same, share the exact same character traits and in general be absolutely psychologically indistinguishable from the original. Moreover this ostensibly teleported person will have memories of her life before being teleported -- she will remember standing in the teleportation booth, experiencing a sudden shift in perspective, and finding herself in the destination booth. In every way this newly created person will feel herself as being simply a continuation of the original and that she has merely instantaneously transported from one place to another.
So to deny that the replica is the very same person is not only to deny that ones total physicality fixes identity, but also that the totality of ones psychological states, including memories, fails to fix identity too! Of course under any materialist based metaphysic the former will entail the latter, but it is pertinent to stress this point.
So how does the materialist escape the seeming paradox the author alludes to? Imagine the following scenario. Imagine that every infinitesimal fraction of a second you are getting teleported from place to place. Obviously if you keep your eyes open you'll just see a confusing blur. But you could close your eyes, and everything would seem to be normal. You could be thinking of a problem, daydreaming, or whatever. Nothing would seem different as compared to when you have your eyes closed normally, except in the teleportation scenario you are continuously being killed and spontaneously coming into being every infinitesimal fraction of a second!
Now if we suppose that precisely this is happening in our second by second everyday existence then there is no paradox.
What this means then is that the materialist has to reject the notion of a persisting self. That's all an illusion. There is only the sense of a self, but that sense corresponds to no real self.
Gualtiero Piccinini's thought experiment reveals that he too is instinctively a strong dualist. In his paper he derides substance dualism, yet affirms that the self is substantial in his teleportation thought experiment.
Incidentally the philosopher Gualtiero Piccinini whose arguments I address here has actually seen this blog entry and has commented in a blog entry here. Unfortunately he doesn't understand my argument, although the people commentating underneath do appear to understand it. It will be interesting to see if he has modified his contribution to the volume.
UPDATE: It's almost 3 years since I wrote the above. Myth of an Afterlife: The Case Against
Life After Death has now finally been published and I shall be
reviewing it in due course.
Further Update 8/5/22 Almost 10 years after my original post. Here is my ~13,000 word review of this book.