Abstract

In this paper, I argue that Humean theories of moral motivation appear preferable to Kantian approaches only if one assumes a broadly foundationalist conception of rational justification. Like foundationalist approaches to justification generally, Humean psychology aims to counter the regress-of-justification argument by positing a set of ultimate regress-stoppers-in this case, unmotivated desires. If the need for regress-stoppers of this type in the realm of practical deliberation is accepted, desires do indeed appear to be the most likely candidate. But if this foundationalist strategy is rejected, there is no longer any reason to suppose that all motivation must be traceable to some extra-rational incentive. This clears the way for a rehabilitation of the Kantian claim that reasons for action can take the form of categorical imperatives. To illustrate this thesis, I show how a conception of practical rationality that incorporates a contextualist model of justification can be developed that treats social norms as reasons for action, without assigning any mediating role to agent desires. a theory of action of this type eliminates the gap between moral obligation and action, and so articulates the fundamental Kantian intuition that acting on the basis of moral principle-and with disregard for self-interest-is just one way of acting rationally.