Anthropic Bias Observation Selection Effects in Science and Philosophy Nick Bostrom
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 This gives  (with  ). Hence, according to  , the blackbeards’ credence of T1 should be the same as their credence of T2, which is wrong.
A broader definition of the reference class will give the correct result. Suppose all observer-moments in Blackbeards and Whitebeards are included in the same reference class (figure 10):  This gives  . That is, observer-moments that find that they have black beards obtain some reason to think that T1 is true.
This establishes boundaries for how the reference class can be defined. The reference class to which an observer-moment  belongs consists of those and only those observer-moments that are relevantly similar to . We have just demonstrated that observer-moments can be relevantly similar even if they are subjectively distinguishable. And we saw earlier that if we reject the paradoxical recommendations in Adam & Eve, Quantum Joe and UN++ that follow from using the universal reference class definition  then we also must maintain that not all observer-moments are relevantly similar. We thus have ways of testing a proposed reference class definition. On the one hand, we may not want it to be so permissive as to give counterintuitive results in Adam & Eve et al. (Scylla). On the other hand, it must not be so stringent as to make cosmological theorizing impossible because of the freak-observer problem (Charybdis). A maximally attractive reference class definition would seem to be one that steers clear of both these extremes.
Directory: preprints preprints -> Digitally-assisted discovery and proof preprints -> Reorienting the Logic of Abduction preprints -> Supplementary Material Table 1 Download 9.31 Mb. Share with your friends:
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