Abstract

In principle, any token belief can be evaluated practically as well as epistemically . My thesis is an exploration of what I take to be philosophically interesting issues which arise from reflection on this commonplace. ;In the first part of the thesis, I explore the question of whether the fact that beliefs can be evaluated practically can have normative upshot: that is, whether practical evaluations can make a difference to what one should believe, or to how one should act. I argue that, although practical considerations cannot rationalize beliefs, they can rationalize acting in ways that lead to the acquisition of practically advantageous beliefs---including beliefs which it would be irrational to hold. In the course of the inquiry, I pursue questions about the extent to which our beliefs are under our voluntary control as well as questions about the distinctive value of being a rational believer, and I attempt to apply the lessons which emerge from my discussion of belief to other propositional attitudes such as regret, fear, and desire. ;In the second part of the thesis, I develop the hypothesis that the oft-noted 'epistemic unscrupulousness' displayed by great scientists at various key historical junctures is an artifact of the practical advantageousness of holding certain kinds of beliefs in the absence of evidence for those beliefs. I argue that this hypothesis has important implications for contemporary debates concerning the rationality and objectivity of scientific progress. In the course of the discussion, I examine norms of conservatism and inference to the best explanation and suggest that, in order to appreciate the distinctive virtues of these norms, one must take practical considerations into account. ;In the third and final part of thesis, I argue against the reductionist view that epistemic goodness is simply a special case of practical goodness, viz. practical goodness in the service of one's cognitive or epistemic aims. I criticize the assumption, common among epistemologists, that there is some general, global cognitive goal relative to which our cognitive practices and efforts are to be assessed. In the more constructive segment of the third part, I contend that although there is a deep and irreducible distinction between epistemic and practical rationality, theoretical reasoning of any significant degree of complexity requires responsiveness to both epistemic and practical reasons, and that theoretical rationality is thus best thought of as a hybrid virtue