Internalism and Externalism about Reasons

Internalism about normative reasons for action, in its broadest characterization, holds that each agent A’s reasons to act are constrained by some motivational fact, M, about A. Different versions of internalism differ on what M is. This chapter examines Bernard Williams’s (1981) influential version of, and argument for, internalism, in a broadly sympathetic vein. I isolate the key assumptions driving Williams’s argument, tracing their influence on Williams’s views and on the literature he sparked; and arguing that each assumption, when properly understood, is more plausible than some recent critics think. The upshot is that Williams’s internalism, and the assumptions that generate it, remain serious contenders on the contemporary scene.