Abstract
This chapter surveys essentialist and anti-essentialist theories of sex and gender. It does so by engaging three approaches to sex and gender: externalism, internalism, and contextualism. The chapter also draws attention to two key debates about sex and gender in the feminist literature: the debate about the sex/gender distinction (the distinction debate) and the debate about whether sex and gender have essences (the essentialism/anti-essentialism debate). In addition, it describes three problems that theories of sex and gender tend to face: the Inclusion Problem, the Definition Problem, and the Exclusion Problem. Lastly, the chapter highlights why the division between essentialist and anti-essentialist accounts of sex and gender is not clear.