An academic division of labor resulted from the distinction between sex and gender. Sex remained a productive topic (excuse the pun) for biologists, who are interested in the genetic, developmental, and chemical pathways of male/female dimorphism. People in the social sciences and humanities, by contrast, made gender, not sex, the subject of their work. In gender studies, we learn about the ways that men and women “perform” their respective roles—people of male sex can perform as female gender, and vice versa, by adopting modes of speech, dress, behavior, and even values. There is no talk of innate instincts or brain differences in gender studies.
The French philosopher Michel Foucault set the agenda when he lamented, as early as 1976, that “the notion of sex made it possible to group together, in an artificial unity, anatomical elements, biological functions, conducts, sensations, and pleasures, and it enabled one to make use of this fictitious unity as a causal principle.” Following this approach, more-recent theorists like Anne Fausto-Sterling and Judith Butler have argued that even the biological categories of sex are just artificial inventions, designed to keep women and intersexed peoples down. Society, they suggest, decides which of us are males and which are females—pushing everyone into rigid binary categories.
There are two main arguments that are usually offered in defense of this controversial thesis that sexual dimorphism is political rather than ontological. One is based on a general critique of knowledge (an epistemological argument), and the other on a specific picture of reality (a metaphysical argument). I will offer counterarguments to both.