How do we know that particular answers in bioethical controversies are true, or are at least getting closer to the truth? We gain insight into this question by applying Alasdair MacIntyre’s work on the nature of rationality, rational justification, and tradition. Using MacIntyre’s work and the papers in this issue of The Journal of Medicine and Philosophy, I propose a framework for members of particular traditions to judge whether they themselves or other traditions are getting closer to or further away (...) from the truth in particular bioethical questions. Members of different traditions—be it Confucian, Aristotelian, politically liberal, utilitarian, or something else—should look at how they and their theoretical rivals look at empirical data to address bioethical questions, the moral judgments they make, and the laws and regulations they support. Some level of agreement on these issues need not require individual traditions to eschew their foundational premises or values; recognizing the reality of moral pluralism and disagreement should not prevent us from seeing this. Neither, as MacIntyre argues, should pluralism and disagreement obscure that a necessary condition for successful rational exchange and adjudication between competing traditions is granting authority to certain norms and virtues. (shrink)