Abstract
Despite being somewhat long in the tooth at the time, Aristotle, Hume and Kant were still dominating twentieth century moral philosophy. Much of the progress made in that century came from a detailed working through of each of their approaches by the expanding and increasingly professionalized corps of academic philosophers. And this progress can be measured not just by the quality and sophistication of moral philosophy at the end of that century, but also by the narrowing of some of the gaps between Aristotelian, Humean and Kantian philosophers.