While investigating the sources from which pagan virtue can spring, we distilled three necessary conditions for that virtue to count as authentic virtue: ordainability, good source, right reason. Each of these three conditions is necessary, without any one alone sufficient to establish the graceless agent in a virtuous life. Perhaps because Aquinas explicitly discusses it in relation to pagan virtue, most contemporary attention focuses on the ordainability condition. But it is not fair to say this is the only one to which he attends. Not only does he treat of the right reason condition, but it is easily foreseen given the role recta ratio serves in Aquinas’s moral science. It is certainly one of the ways his moral science is so indebted to Aristotelian ethics.