Abstract

The project of this paper is to address a complaint, by Prichard, against Plato and other ancients, as committing a basic “mistake” in moral philosophy. The basic mistake is in thinking that we are capable of giving reasons for the requirements of duty, rather than directly and immediately apprehending those requirements. Prichard’s argument that this is a mistake consists in an argument that attempts to give reasons for such requirements always fail. He classes those attempts into two kinds, and one of those kinds is exemplified by Plato. (I leave aside here the second kind.) My response is to show two things. First, Plato does not make the egregious mistake of substituting interest for duty, and thus giving the wrong kind of reason for duty’s requirements, as Prichard alleges. This allegation assumes, first, that they duty and interest are entirely distinct notions, and, second, that we have a clear and accurate sense of the contents and bounds of each. Neither of these assumptions is accepted by Plato, and appreciating what their denial involves is essential to grasping the enterprise of moral philosophy as the ancients practiced it. Second, we should see that enterprise as being comprehensive in a sense Prichard simply ignores. They are seeking what we now call wide reflective equilibrium in judgments about both duty and interest, and to see this I focus on a puzzle in how to understand much of ancient moral philosophizing. This puzzle is how to make sense of the work the ancients see formal constraints on happiness as supporting their preferred views of happiness (or interest). I claim that they way they do so is a mess on any picture other than one of a search for wide reflective equilibrium, and this way of engaging not only our thoughts about duty and interest, but what it is to be human, and to lead a human life, make the ancient model far more satisfying than Prichard’s recommendation that we give it all up as a mistake.