Some philosophers think that knowledge or justification is both necessary and sufficient for rational action: they endorse knowledge-action or justification-action biconditionals. This paper offers a novel, metaphysical challenge to these biconditionals, which proceeds with a familiar question: What depends on what? If you know that p iff it is rational for you to act on p, do you know that p partly because it is rational for you to act on p, or is it rational for you to act on (...) p partly because you know that p? And a structurally similar question can be asked regarding justification-action biconditionals. I argue that proponents of these biconditionals cannot give a satisfactory answer to these questions. This is because each direction of these biconditionals strongly supports an opposite order of explanation to the one that is supported by the other direction. Given the traditional assumption that metaphysical explanations—even partial ones—are asymmetric, I argue that these biconditionals should be rejected. While knowledge might be necessary for rational action, and it might be sufficient, it cannot be both. And the same goes for justification. (shrink)

According to the pragmatic hypothesis testing theory, how much evidence we require before we believe something varies depending on the expected costs of falsely believing and disbelieving it. This theory has been used in the self-deception debate to explain our tendencies towards self-deceptive belief formation. This article argues that the application of this theory in the self-deception debate has overlooked the distinction between belief and acceptance, and that the theory in all likelihood models acceptance rather than belief, in which case (...) it is probably not relevant to the explanation of self-deception. It is suggested, however, that doxastic error costs might be relevant to explaining some types of self-deception, though they feature in an evolutionary explanation of it rather than a psychological one. (shrink)

According to evidentialist views, credence in a proposition p should be proportional to the degree of evidential support that one has in favor of p. However, empirical evidence suggests that our credences are systematically sensitive to practical factors. In this article, I provide a cost–benefit analysis of credences' practical sensitivity. The upshot of this analysis is that credences sensitive to practical factors fare better than practically insensitive ones along several dimensions. All things considered, our credences should be sensitive to practical (...) factors. (shrink)