Abstract

Suppose you woke up one morning having utterly forgotten what year it was, or, indeed, what century and what millennium it was, but with all your cognitive faculties otherwise intact. In particular, you remember that human population increases monotonically with time, implying that, in later years, there are far more positions you could be occupying in the whole set of all persons who have ever lived or will live. Then, John Leslie tells us, you will apply your knowledge of probability theory in a certain way and conclude that, whatever year you may be in, it is probable that it is uncomfortably close to the point at which the human species meets its quietus. You think, “My God, I’ve overslept and missed most of history.”