This paper is a critical examination of Harry Collins's investigation into a third form of knowledge, “interactional expertise.” We argue that although Collins makes a genuine contribution to the phenomenological literature on expertise, his account requires further critical evaluation and response due to pragmatic and ontological considerations. We contend that by refining (in some questionable ways) the category of interactional expertise so as to create epistemological equivalence between activists, sociologists, critics, journalists, and some science administrators, Collins potentially undermines the value (...) that a more rigorously construed concept of interactional expertise might have. We further show that Collins misunderstands the nature of embodiment in a way that is exacerbated by the sociological perspective that he adopts. (shrink)