Abstract

My thesis argues that the debate about the nature of practical reasoning is hindered by an erroneous distinction between theoretical and practical reasoning which, when redrawn, allows for a better account of the normative force of practical reasons. ;Typically, reasoning about action is taken to bear explanatory burdens which reasoning about belief is not. Rational constraints are thought to be categorically binding in theoretical reasoning, but only hypothetically binding in practical reasoning. Instrumentalists, who hold that reason's role in action is limited to the generation and evaluation of means to ends, ends set by something other than reason itself cannot appeal directly to reason's authority in the explanation of how reasons rationally compel action. Instead, they focus on the question of what motivates action. This focus obscures the more fundamental question, 'how are judgements, practical and theoretical, normatively binding?' It prejudices an analysis of practical reason by supposing it to involve normative commitments which theoretical reasoning doesn't. ;I outline Wilfrid Sellars's analysis of the normative commitments implicit in theoretical reasoning and apply its lessons to an analysis of practical reasoning. In Sellars's terminology, attempts to justify by appeals to non-normative facts employ "mongrel concepts," which illegitimately conflate the causal and normative orders of explanation. Using this concept as a gauge for evaluating accounts of theoretical and practical reasoning, I show how views that characterize reasons simultaneously as mental particulars, merely descriptively true of agents, and as general standards authorizing conduct, fail. I argue that both instrumentalist and Kantian accounts of practical reason invoke mongrel concepts. ;To focus on the deeper question of how reasons are binding, I redraw the distinction between practical and theoretical reason, showing that puzzles purportedly specific to moral reasoning are instead, puzzles for rationality itself. I argue that the normative authority of reasons is explained by their public character. The practice of giving and asking for reasons, and the inferences which reasons authorize within that practice, must be understood in intersubjective terms on pain of unintelligibility. According to intersubjectivism, what we have objective reason to do is a function of what good practical discourse would vindicate.