Title:
Probability by Convention
Abstract:
Probabilism -- the doctrine that ideally rational degrees of belief conform to the calculus of probabilities -- is habitually defended by citing Dutch-book and accuracy-dominance arguments. Yet these arguments rely on premises that are not plausibly necessary truths. I argue that
the premises in question can be understood as fixing a convention (along the lines of Poincaré's conventionalism about Euclidean geometry). Relaxing these premises leads to alternative calculi which are intertranslatable with the probability calculus. This applies to Dutch-book and accuracy-dominance arguments alike; I show a general mathematical correspondence between them.