Abstract
Since Phillipa Foot’s paper ‘Morality as a System of Hypothetical Imperatives’ was published some twenty-five years ago, questions about categorical imperatives and the alleged rationality of acting morally have been of central concern to ethicists. For critics and friends of Kantian ethical theories, these questions have special importance. One of the distinctive features of Kantian ethical theories is that they claim that there are categorical imperatives: imperatives which dictate which actions one should follow insofar as one is rational.This way of parsing morally right action as a kind of rational action seems to side-step at least some of the anti-realist objections that other kinds of moral theories must face.1 Instead, the Kantian must defend the claim that failure to act morally is a failure of rationality. Rationality as a normative concept is sometimes thought to be more clear and perhaps more objective than other basic normative concepts.