Self-locating belief and the Sleeping Beauty problem 论文

摘要

--- all that matters is that the person put to sleep believes that the setup is as I have described it. 1 First answer: 1/2, of course! Initially you were certain that the coin was fair, and so initially your credence in the coin's landing Heads was 1/2. Upon being awakened, you receive no new information (you knew all along that you would be awakened). So your credence in the coin's landing Heads ought to remain 1/2. Second answer: 1/3, of course! Imagine the experiment repeated many times. Then in the long run, about 1/3 of the wakings would be Heads-wakings --- wakings that happen on trials in which the coin lands Heads. So on any particular waking, you should have credence 1/3 that that waking is a Heads-waking, and hence have credence 1/3 in the coin's landing Heads on that trial. This consideration remains in force in the present circumstance, in which the experiment is performed just once. I will argue t