Bayesianism and IBE

Different views have been proposed about how Inference to the Best Explanation (IBE) and Bayesianism might be compatible with one another. One is a hybrid view, according to which explanatory considerations play a role in driving the Bayesian machinery. Another is an ‘emergent compatibilist’ view, in which an independently motivated Bayesian model of IBE is provided, so that explanatory considerations emerge from the Bayesian machinery rather than driving it. Specific scientific arguments can serve as test cases for these general views. The chapter argues that the case of Williams’ argument against group selection, discussed by Elliott Sober, is better understood with the emergent compatibilist picture, than with the hybrid view. This analysis of the case challenges Elliott Sober’s claim that the epistemic significance of appeals to the explanatory virtue of parsimony is highly case-specific. Instead, a more unified picture of IBE and its connection to Bayesianism is suggested.

The Evidential Impact of Explanatory Considerations

Explanationism is an attractive family of theories of epistemic justification. In broad terms, explanationism is the idea that what a person is justified in believing depends on their explanatory position. At its core, explanationism involves commitment to the claim that the fact p would best explain a body of evidence if p were true is itself evidence that p is true. In slogan form: explanatoriness is evidentially relevant. Despite its plausibility, explanationism has been criticized for various reasons. This chapter strengthens the case for explanationism by defending it from a recent attack by Elliott Sober and William Roche.