Now might be a good time to mention “full non-indexical conditioning”, which I think is incontestably an advance on SSA and SIA.
To be sure, FNC still faces the severe problem that observer-moments cannot be individuated, leading (for instance) to variations on Sleeping Beauty where tails causes only a ‘partial split’ (like an Ebborian midway through dividing) and the answer is indeterminate. But this is no less of a problem for SSA and SIA than for FNC. The UDT approach of bypassing the ‘Bayesian update’ stage and going straight to the question ‘what should I do?’ is superior.
Neal’s approach (even according to Neal) doesn’t work in Big Worlds, because then every observation occurs at least once. But full non-indexical conditioning tells us with near certainty that we are in a Big World. So if you buy the approach, it immediately tells you with near certainty that you’re in the conditions under which it doesn’t work.
What I especially like about FNC is that it refuses to play the anthropic game at all. That is, it doesn’t pretend that you can ‘unwind all of a person’s observations’ while retaining their Mind Essence and thereby return to an anthropic prior under which ‘I’ had just as much chance of being you as me. (In other words, it doesn’t commit you to believing that you are an ‘epiphenomenal passenger’.)
FNC is just ‘what you get if you try to answer those questions for which anthropic reasoning is typically used, without doing something that doesn’t make any sense’. (Or at least it would be if there was a canonical way of individuating states-of-information.)
Now might be a good time to mention “full non-indexical conditioning”, which I think is incontestably an advance on SSA and SIA.
To be sure, FNC still faces the severe problem that observer-moments cannot be individuated, leading (for instance) to variations on Sleeping Beauty where tails causes only a ‘partial split’ (like an Ebborian midway through dividing) and the answer is indeterminate. But this is no less of a problem for SSA and SIA than for FNC. The UDT approach of bypassing the ‘Bayesian update’ stage and going straight to the question ‘what should I do?’ is superior.
Neal’s approach (even according to Neal) doesn’t work in Big Worlds, because then every observation occurs at least once. But full non-indexical conditioning tells us with near certainty that we are in a Big World. So if you buy the approach, it immediately tells you with near certainty that you’re in the conditions under which it doesn’t work.
Sure, that’s a fair criticism.
What I especially like about FNC is that it refuses to play the anthropic game at all. That is, it doesn’t pretend that you can ‘unwind all of a person’s observations’ while retaining their Mind Essence and thereby return to an anthropic prior under which ‘I’ had just as much chance of being you as me. (In other words, it doesn’t commit you to believing that you are an ‘epiphenomenal passenger’.)
FNC is just ‘what you get if you try to answer those questions for which anthropic reasoning is typically used, without doing something that doesn’t make any sense’. (Or at least it would be if there was a canonical way of individuating states-of-information.)