Thanks for these thoughts, Kaj.
It's a worthwhile effort to overcome this problem, but let me offer a mode of criticising it. A lot of people are not going to want the principles of rationality to be contingent on how long you expect to live. There are a bunch of reasons for this. One is that how long you expect to live might not be well-defined. In particular, some people will want to say that there's no right answer to the question of whether you become a new person each time you wake up in the morning, or each time some of your brain cells die. On the other extreme, it might be the case that to a significant degree, some of your life continues after your heart stops beating, either through your ideas living on in others' minds, or by freezing yourself. If you freeze yourself for 1000 years, then wake up again for another hundred, should the frozen years be included in defining PESTs, or not? It seems weird that rationality should be dependent on how we formalise the philosophy of identity in the real world. Why should PESTs be defined based on how long you expect to live, compared to how long you expect humanity as a whole to live, or on the expected lifetime of anything else that you might care about.
Anyhow, despite my criticism, this is an interesting answer - cheers for writing this up.
Thanks!
I understand that line of reasoning, but to me it feels similar to the philosophy where one thinks that the principles of rationality should be totally objective and shouldn't involve things like subjective probabilities, so then one settles on a frequentist interpretation of probability and tries to get rid of subjective (Bayesian) probabilities entirely. Which doesn't really work in the real world.
...One is that how long you expect to live might not be well-defined. In particular, some people will want to say that there's no right answer to the que
Summary: the problem with Pascal's Mugging arguments is that, intuitively, some probabilities are just too small to care about. There might be a principled reason for ignoring some probabilities, namely that they violate an implicit assumption behind expected utility theory. This suggests a possible approach for formally defining a "probability small enough to ignore", though there's still a bit of arbitrariness in it.