Bayesian psychology, in what is perhaps its most familiar version, is incomplete: Jeffrey conditionalization is not a complete account of rational belief change. Jeffrey conditionalization is sensitive to the order in which the evidence arrives. This order effect can be so pronounced as to call for a belief adjustment that cannot be understood as an assimilation of incoming evidence by Jeffrey's rule. Hartry Field's reparameterization of Jeffrey's rule avoids the order effect but fails as an account of how new evidence (...) should be assimilated. (shrink)

Bayesian psychology, in what is perhaps its most familiar version, is incomplete: Jeffrey conditionalization is not a complete account of rational belief change. Jeffrey conditionalization is sensitive to the order in which the evidence arrives. This order effect can be so pronounced as to call for a belief adjustment that cannot be understood as an assimilation of incoming evidence by Jeffrey's rule. Hartry Field's reparameterization of Jeffrey's rule avoids the order effect but fails as an account of how new evidence (...) should be assimilated. (shrink)

There is no set Δ of probability axioms that meets the following three desiderata: (1) Δ is vindicated by a Dutch book theorem; (2) Δ does not imply regularity (and thus allows, among other things, updating by conditionalization); (3) Δ constrains the conditional probability q(·,z) even when the unconditional probability p(z) (=q(z,T)) equals 0. This has significant consequences for Bayesian epistemology, some of which are discussed.

In my paper “On the Probabilities of Conditionals,” I claimed, mistakenly, that David Lewis’s four triviality results and Alan Hájek’s proof depend on the application of the following principle to conditionals containing nested conditionals.

Proponents of the projection strategy take an epistemic rule for the evaluation of English conditionals, the Ramsey test, as clue to the truth-conditional semantics of conditionals. They also construe English conditionals as stronger than the material conditional. Given plausible assumptions, however, the Ramsey test induces the semantics of the material conditional. The alleged link between Ramsey test and truth conditions stronger than those of the material conditional can be saved by construing conditionals as ternary, rather than binary, propositional functions with (...) a hidden contextual parameter. But such a ternary construal raises problems of its own. (shrink)

In my paper “On the Probabilities of Conditionals,” I claimed, mistakenly, that David Lewis’s four triviality results and Alan Hájek’s proof depend on the application of the following principle to conditionals containing nested conditionals.

In my paper “On the Probabilities of Conditionals,” I claimed, mistakenly, that David Lewis’s four triviality results and Alan Hájek’s proof depend on the application of the following principle to conditionals containing nested conditionals.

In this paper, I derive a syntactic procedure for revising theories in propositional logic from considerations of indifference and informational economy (minimality). The procedure is very flexible. It allows us to make use of information about the relative epistemic merit (entrenchment) of the sentences in the theories whenever such information is available, and, unlike other procedures proposed in the literature, yields plausible results even for very simple entrenchment orderings.