> This is true as a practical matter, but it doesn't have much bearing on the thought-experiment. This is what I was getting at. In the pure thought experiment

> This is true as a practical matter, but it doesn't have much bearing on the thought-experiment. This is what I was getting at. In the pure thought experiment it's a lot easier to go along with saying that both the pre and post replacement entity is the same person. But people who are ok with that ideal are usually going to be more worried once you involve those real effects that diverge the actual experiment from the thought experiment. If the process takes time then there is time for divergence and that possibility can cause anxiety. If there is no time then it is simply a question of "If you got instantly replaced with an exact duplicate, are you still the same person?" which is meaningless, you would have no possible way of knowing it had happened. You should be more worried about sleep actually being death and the person who wakes up being a different person. >> I would view a perfect clone of me to be the same as me. >But it isn't. If it suffers, you do not. You might not even be aware of its existence. Let me rephrase this. Yes the clone suffers and the original wouldn't be aware of it. But I consider both people to be the same person. This is not to mean they are some sort of shared consciousness. Let's imagine you had a clone and an original stuck on an island with supplies to last 4 weeks. You know help will arrive in 8 weeks, so one of you needs to die to allow the other to use the supplies to last that long. If it were me in that scenario I'd just flip a coin and the one who wins gets to survive on the supplies. I consider both as valid as the other to the claim of being me.