INTERNAL REASONS AND THE OUGHT-IMPLIES-CAN PRINCIPLE1

Abstract

The task of this essay is to use the ought-implies-can principle (OIC) to clarify and defend Bernard Williams’ claim that all reasons are internal. On the interpretation offered here, the internalism/externalism controversy initiated by Williams is about the indexicality of normative practical reasons. The central question is this: Are all of our reasons anchored to our current beliefs and desires (as internalists claim), or might we have reasons that are in no way tied to such contingent facts about us (as externalists claim)? I will contend that although Williams provides two different arguments against externalism, only one of them can be used to effectively defeat external reasonclaims. The first argument, according to which only internal reasons can explain rational action, will be largely ignored in favor of the second argument, which appeals to OIC as a conceptual constraint on normative reasons. Although OIC cannot directly support internalism, a plausible version of it can be used to falsify external reason-claims and thereby render internalism the default theory of practical reasons. Since the distinction between “internal” and “external” reasons has itself been widely misunderstood, I devote the first section to explicating Williams’ thesis. In the second section, I discuss the conception of sound deliberation on which internalism depends. In section three, I reconstruct Williams’ central argument for internalism by recasting several examples he develops as implicit appeals to OIC. In the fourth section, I discuss the relationship between normative reasons and “ought” statements. Finally, in the fifth section I defend a relatively strong version of OIC and then explain why this version vindicates Williams’ suspicion that all external reason-claims are false.