Please use this topic to discuss A Fair Deal for Everettians by David Papineau
, which is chapter 7
of the July book of the month Many Worlds?: Everett, Quantum Theory, & Reality edited by Saunders, Barrett, Kent, Wallace
. We are discussing this book chapter-by-chapter, including a discussion for the introduction and the transcript at the end. Please do not post in this topic until you have read chapter 7
What do you think of this chapter? What do you think of Papineau's ideas and arguments? If you chose mostly disagree or utterly disagree for the poll, then on what specifically do you disagree with Papineau?
While I do not adhere to the MWI, I agree with much of David Papineau's points about probability and the overall rebuttal of the claim that EQM has more trouble with probability than single-world physics. However, in some ways, I think Papineau gives into the opposition to much by even engaging the issue of probability as such. Indeed, I might argue that "objective probability" simply doesn't exist. Of course, that would render the principal principle in such a case moot. In other words, I think all there is is subjective or epistemic probability in a deterministic world. In that sense, single-world interpretations seem to struggle with probability simply because they have to not only assert that some truly random but seemingly probability-obeying events occur which make the world not deterministic and then find a way to justify behavior and credence based on that. I agree that MWI and EQM don't struggle in those ways, but I think Papineau's arguments while essentially saying a similar story in other semantics give too much leeway for argument. I think the same point can be made by denying objective probability. Alternatively, if we believe "objective probability" exists in a deterministic universe such as presumably under MWI, then I think we need yet a third category of probability, perhaps called 'ontological probability', based on an ontological randomness (i.e. indeterminacy) which perhaps by definition does not exist in MWI.
Anyway, what do you think?