This article addresses the question of the relation between disciplines and transdisciplinary practices and concepts through a discussion of the relationship between philosophy and the emblematically transdisciplinary practice of feminist theory, via a discussion of interdisciplinarity and related terms in gender studies. It argues that the tendency of philosophy to reject feminist theory, as alien to it as a discipline, is in a sense correct, to the extent that the two defining features of feminist theory -its constitutive tie to a political agenda for social change and the transdisciplinary character of many of its central concepts -are indeed at odds with, and pose a threat to, the traditional insularity of the discipline of philosophy. If feminist philosophy incorporates feminist theory, its transdisciplinary aspects thus open it up to an unavoidable contradiction. Nonetheless, I will argue, this is a contradiction that can and must be endured and made productive.