While I was lying in bed at 4am, unable to sleep, I started to get philosophical, as one does while lying in bed at 4am, unable to sleep. In fact I’m currently lying in bed at 4am, unable to sleep, and the philosophy is most likely the reason. Let me try to articulate exactly what is keeping me awake.
Hopefully by now everyone has thought about what would happen if they made an exact copy of themselves. The copy has the same memories and thoughts as the original, and is indistinguishable to any third parties who know the original. If the original was to die, and be replaced by the copy without anyone knowing, as far as everyone is concerned, nothing happened. It could even be arranged such that the copy didn’t know that they were a copy. But note that this won’t allow a person to cheat death. If such a copy could be made, it could coexist with the original, and so it must have its own stream of consciousness. The original doesn’t now experience the world through the eyes of the copy as well as themselves. From the point of copying, the copy is their own person, though as far as the copy is concerned, they may as well be the original. But I digress, and while this is in itself a fascinating topic, it’s not what’s keeping me up.
Let’s say that the “Stream of Consciousness” refers to your sense of self - the sense that you have free will (regardless of whether or not you actually do). Now, when you wake up, your stream of consciousness begins, and you spend the day as yourself. Then you go to sleep, and the stream of consciousness ends. The next day, when you wake up, a stream of consciousness begins again. But this is a new stream of consciousness. The old one is gone, and has been replaced. You keep your memories and personality and the things that define you, but the “self” that represents your stream of consciousness is new.
This raises the question: What happened to your old self? Also, this blurs the distinction between “Falling asleep and waking up” and “Being replaced by an exact copy of yourself”, as in both cases a new stream of consciousness is inhabiting a body and mind identical to yours. It certainly raises some dire implications about falling asleep. If when you wake up, the only thing assuring you that you are indeed yourself is your memory, a copy could wake up tomorrow, and it would effectively be you (from its point of view). Or you could have woken up this morning as a copy of your former self, and have no idea.
Nevertheless, it is late, and I have things to do tomorrow. Goodbye.