It often seems incorrect to say that psychiatric conditions are diseases, and equally incorrect to say that they are not. This results in what would seem to be an unsatisfactory stalemate. The present essay examines the considerations that have brought us to such a stalemate in our discussions of autism. It argues that the stalemate in this particular case is a reflection of the fact that we need to find the logical space for a position that rejects both positive and (...) negative answers. It then suggests one way in which we might find such space, by applying Michael Dummett’s notion of semantic disharmony. (shrink)