RE: reasoning under computational limitations

Nick Bostrom (
Tue, 30 Mar 1999 14:13:09 +0000

Billy Brown wrote:

> Hmmm. Wouldn't this be more correctly phrased as a prediction about the
> number of gaussian humans that will exist in the future? The number of
> posthumans currently living appears to be 0, which means you'd need an
> entirely different chain of reasoning to predict *their* likelihood of
> survival.

It depends on whether posthumans and humans are in the same reference class, i.e. whether we should reason as if we were randomly sampled from the class of both posthumans and humans, or from the class consisting of only humans. An unsolved problem in my opinion. Notice that it would seem more difficult to argue that posthumans are in a different reference class if humans could actually *personally become* posthumans while remaining the same person.

Nick Bostrom Department of Philosophy, Logic and Scientific Method London School of Economics