A tradition, in MacIntyre's sense, is not a set of static beliefs inherited uncritically from the past but an ongoing argument about the goods constitutive of a particular form of life. A living tradition is one in which the central questions are kept open and continuously debated; a dead tradition is one whose constitutive questions are no longer asked. Traditions develop — they respond to challenges, resolve internal conflicts, extend their resources to new problems, and sometimes undergo radical revision when confronted with challenges they cannot resolve from within their own terms. The Aristotelian tradition, for example, underwent decisive transformation when Augustine, and then Aquinas, integrated it with Christian theology.
Each tradition has its own standards of rational enquiry — its own criteria for what counts as evidence, what problems are important, what kinds of argument are persuasive. These standards are not arbitrary; they have been refined through the tradition's history of enquiry, its successes and failures, its encounters with rival traditions. To assess a tradition's rationality is not to apply some external, tradition-neutral standard but to examine whether its internal standards are consistently applied, whether it can resolve its own problems, and whether it can address the challenges posed by rival traditions without abandoning its fundamental commitments.
MacIntyre's most pointed argument in Whose Justice? is that liberalism is itself a tradition, despite its claims to represent universal rational principles accessible to any unprejudiced mind. Liberal political philosophy has a history — it emerged from specific intellectual and social conditions; it has developed through internal debates; it has its own canonical texts and standards of argument. The liberal pretence to tradition-neutrality is a mask for the particular tradition's claim to hegemony — a claim that, once exposed, can be assessed like any other tradition's claim. MacIntyre argues that liberalism, when honestly examined, is unable to resolve the deepest questions of justice on its own terms, and that Thomistic Aristotelianism provides the more coherent and resourceful alternative.
The argument of Whose Justice? extends the tradition-based epistemology implied in After Virtue into a systematic philosophy of enquiry. MacIntyre's position is sometimes compared to Kuhn's account of paradigms, but MacIntyre explicitly distances himself from Kuhn's relativism: traditions can be compared and one can be shown to be rationally superior to another.
