Fri Sep 1, 2023
Snow Xueyin Zhang (UC Berkeley)
Imaging and Conditionalization Revisited
Many think that there are two kinds of supposition, indicative and subjunctive, and they call for different hypothetical revisions of one’s degrees of belief (credences). Rational credal revision under indicative supposition goes by Bayesian conditionalization, whereas rational credal revision under subjunctive supposition goes by imaging. But why is imaging the rational way to revise one’s credences under subjunctive supposition (assuming that it is)? The primary goal of this talk is to sketch an answer to this question by proving a Dutch book theorem and an accuracy-dominance theorem for imaging, parallel to de Finetti’s Dutch book and accuracy-dominance theorems for conditionalization. If time permits, we’ll discuss how these results shed light on the recent debates about probabilities of conditionals and partial supposition.