Abstract

In what follows I examine the following question: does it make a difference in moral psychology whether one adopts Aristotle's ordinary or Kant's revisionist definition of virtue as habit? Points of commensurability and critical comparison are provided by Kant's attempt to refute Aristotle's definition of virtue as a mean and by the moral problems of ignorance and weakness. These two problems are essential topics for moral psychology. I show two things. First, Kant's definition is revisionist because he excludes from moral habit-formation what Aristotle includes, that is, practice in prudential calculation of a mean, and habit-formation by repetition. This follows from Kant's insistence that an act is virtuous only if the moral agent is willing freely and universally. Secondly, Aristotle's virtues modify behavior directly, whereas Kant's virtues modify behavior indirectly by creating moral feeling which, in turn, represses the temptations of the natural inclination. I suggest, thirdly, that as one approximates Kant's ideal of perfect virtue, entailed by the broad duties of beneficence and self-perfection, the difference in kind invented by Kant between virtue and prudence, as a morally neutral rational skill, erodes and becomes a difference in degree. I conclude that Aristotle's ordinary definition of virtue is better able to modify human behavior and solve these two moral problems.