Jeffrey imaging revisited

Abstract

In ‘The logic of partial supposition’ (Analysis vol. 81), Benjamin Eva and Stephan Hartmann investigate partial imaging , a credence-revision method which combines the partiality familiar from Jeffrey Conditioning(The Logic of Decision , 1983 ) with the formal notion of imaging familiar from Lewis’s ‘Causal decision theory’ (1981 ). They argue that because partial imaging is non-monotonic, it ‘fail[s] to provide a plausible account of the norms of partial subjunctive suppositions’. In this note, I present a notion of partial imaging that does satisfy monotonicity, and discuss some of the applications and ramifications. The account frames conditioning as a form of imaging, and rejects Gärdenfors’s principle of linearity in ‘Imaging and conditionalization’ (1982 ).