Yes, the choice of reference class is the core shaky step for all anthropic arguments. It’s analogous to a choice of prior in ordinary Bayesian reasoning, but at least priors are in practice informed by previous experience of what our universe is like. In anthropic reasoning, we (in theory) discard all knowledge of how our universe works, and then treat all our observations including who we are and what sort of universe (and society) we live in as new evidence that we’re supposed to use to update the relative weight of various hypotheses.
In principle it’s a reasonable idea, but in practice we can’t even apply it to drastically simplified toy problems without disagreements. My estimate of the actual reliability of such arguments in discovering true knowledge about the world is near zero, but they’re still fun to talk about sometimes.
Yes, the choice of reference class is the core shaky step for all anthropic arguments. It’s analogous to a choice of prior in ordinary Bayesian reasoning, but at least priors are in practice informed by previous experience of what our universe is like. In anthropic reasoning, we (in theory) discard all knowledge of how our universe works, and then treat all our observations including who we are and what sort of universe (and society) we live in as new evidence that we’re supposed to use to update the relative weight of various hypotheses.
In principle it’s a reasonable idea, but in practice we can’t even apply it to drastically simplified toy problems without disagreements. My estimate of the actual reliability of such arguments in discovering true knowledge about the world is near zero, but they’re still fun to talk about sometimes.