Alasdair MacIntyre has developed a theory of the rationality of traditions that is designed to show how we can maintain both the tradition-bound nature of rationality, on the one hand, and non-relativism, on the other. However, his theory has been widely criticized. A number of recent commentators have argued that the theory is either inconsistent with his own conception of rationality or else is dependent on the standards of his particular tradition and therefore fails to defuse the threat of relativism. In the present essay, I argue that this objection is mistaken.