Pluralism has become a buzzword in International Relations. It has emerged in a number of linked literatures and has drawn the support of an unusual coalition of scholars: advocates of greater methodological diversity; those who feel that IR has degenerated into a clash of paradigmatic “-isms”; those who favor a closer relationship between academics and policy-makers; and those who wish to see greater reflexivity within the field. Perhaps unsurprisingly, no single vision of pluralism unites these scholars; they appear to be using the term in divergent ways. Accordingly, our aim is threefold. First, we wish to highlight this odd state of affairs, by placing it in disciplinary and intellectual context. Second, we distinguish between plurality—the de facto recognition that IR has become a more diverse field—and pluralism—a normative position which values that diversity, given the public vocation of social science. Finally, we lay out a more consistent understanding and defense of pluralism in those latter terms. We argue that, properly understood, pluralism entails a position of epistemological skepticism: the straightforward claim that no single knowledge system, discipline, theory, or method can claim singular access to truth.