A friend of mine recently asked me if I would live life all over again if I had a chance. Clearly an academic question, but it leads to some interesting speculations, and of course some juicy metaphysical questions.
He first phrased the question, or maybe I should say “posed the thought experiment”, in a way that suggested that I might be a baby again, identical to what I was at birth. Well, of course, right away that brings up the questions, “what is meant by identical”, and “would I know as a baby what I know now?”. Otherwise, I might note, I would probably repeat many of the mistakes and committed the same foolish acts that I have in this life. But what would it even mean, to have the knowledge that one has now? Surely, there is no way to model how a baby, in the true sense of that term, could have the conceptual knowledge that an adult has. A baby has to learn language and concepts, and so there just seems to be no way to make sense out of that idea.
It also raised the question of, “would the world go back to being the exact state it was in when I was a baby?” (we are having fun here, remember, not taking the possibility of this return to a baby thing seriously, but just dancing around some peculiar conceptual problems of identity that I want to return to in a minute). One might imagine, or for the present purposes model, one’s life as a movie, and this would amount to rewinding the film and having it played again. It seems like this would be a meaningless action to choose to do even if one could. What would be the point?…..wouldn’t everything just unfold again the same way (well, maybe, or maybe not, given the possibly chaotic nature of such a historical re-enacting)?
And one might even say, how do I know that hasn’t in fact been done, many times or an infinite number of times, already, in some sense (think of Nietzsche’s idea of “eternal recurrence”). But there would seem to be no point in it……and who would be behind it (what entity or being), and to what purpose? Improvement in one’s character? Hmmm---but without any memory, or at least faint recollections, of the previous cycles, how could one “learn from ones mistakes”?
Some of this territory was explored, or maybe I should say suggested to the philosophically minded viewer, in the film “Groundhog Day”, where a man (Bill Murray) lives one particular day over and over, only seemingly dimly aware that he has done it before, and has repeatedly botched it in some way (the idea was to get him to improve to a point where he was worthy of the female star that he hoped to win over, an unfortunately rather trivial spiritual “chick-flicky” motive for bettering oneself).
Now suppose one agreed to become a baby again, but without the amassed knowledge or memory of his life up through adulthood, and placed in the world in its present state. Well, now we move into a more practical area, as it is interesting to note that one could almost do that now (or probably would be able to in the not too distant future): one would simply have oneself cloned, then one would immediately commit suicide. The cloned cell would develop eventually into a baby, very nearly identical to what you looked like at birth (some inert gestational induced variations might be present, but these would presumably be very small). This illuminates the identity issue that of course your clone would not have your personal consciousness, and would not in any sense of the word, be “you”. But wouldn’t it be essentially the same kind of transformation of somehow magically returning the present you to a baby state, without implementing any of the acquired knowledge or character into the baby?
The same kind of issues arise with the concept of human teleportation, such as is depicted in “Star Trek” (“Beam me up Scotty”). How would one ever know that the teleported human had the essential consciousness, the same sense of being oneself as the original being had? This raises the question of what is consciousness, and what constitutes the peculiar fact of conscious identity. This even arises when we realize that our cells are replaced every so often, such that after several years we are not exactly the same person we were earlier. I suspect this is what bothered the ancient Greeks in their “ship paradox” (although they would have known nothing about cell development and replacement, they would have known that people change over time). In what sense do you retain your identity as your body sheds and acquires new “building blocks”?
These issues are explored very insightfully in Chapter 1 of the book “Riddles of Existence” (by Conee and Sider). In my opinion, they do not “solve” the myriad identity problems, but they do rather thoroughly explore the issues.