The irony of the rejection of the sex/gender distinction is that it renders sociology per se an impossible enterprise. For it is my submission that, contra Hood-Williams (1996) and others, the biological and the social constitute distinct, irreducible levels of reality: to conflate (in a ‘downwards’ or ‘upwards’ direction) the two levels is immediately to render analysis of their relative interplay at best intractable. It is indeed arguable that Hood-Williams is not so much concerned with (rightly) rejecting the so-called ‘additive’ approach to the biological and the social where the biological base is seen a priori as immutable, but more fundamentally with rejecting the necessary dualism of nature and culture (ie the biological and the social). In contradistinction, a realist defence of the sex/gender distinction will be made, involving critical reference to various major writers in the field and offering a brief but tentative discussion of the provenance of gender.