The Logic and Metaphysics Workshop will meet on December 1st from 2:00-4:00 in-person at the Graduate Center (Room 8203) for a talk by Melissa Fusco (Columbia).

Title: Do the Chances Update by Conditionalization?

Abstract: In “Subjectivist’s Guide to Objective Chance”, David Lewis proposes a chance-credence norm he calls the “Principal Principle” (PP).  Lewis also writes, in Sec. 11, that a later chance distribution comes from an earlier one by conditionalization. In this talk, I use an accuracy framework to explore temporalist alternatives to PP. Rather than concerning how an agent’s ur-priors defer to the ur-chances, these temporalist alternatives hold that a rational agent defers to the chances that are current for her. I then sketch how a non-conditionalizing update rule can maximize chance’s own expected accuracy over a language capable of expressing this temporalist norm.  This update rule is based on Goldstein (2020)’s conditionalization-with-normalization.