 Uniessentialism is a sort of individual essentialism. Traditionally philosophers distinguish between kind and individual essentialisms: the former examines what binds members of a kind together and what do all members of some kind have in common qua members of that kind. The latter asks: what makes an individual the individual it is. We can further distinguish two sorts of individual essentialisms: Kripkean identity essentialism and Aristotelian uniessentialism. The former asks: what makes an individual that individual? The latter, however, asks a slightly different question: what explains the unity of individuals? What explains that an individual entity exists over and above the sum total of its constituent parts? (The standard feminist debate over gender nominalism and gender realism has largely been about kind essentialism. Being about individual essentialism, Witt’s uniessentialism departs in an important way from the standard debate.) From the two individual essentialisms, Witt endorses the Aristotelian one. On this view, certain functional essences have a unifying role: these essences are responsible for the fact that material parts constitute a new individual, rather than just a lump of stuff or a collection of particles. Witt’s example is of a house: the essential house-functional property (what the entity is for, what its purpose is) unifies the different material parts of a house so that there is a house, and not just a collection of house-constituting particles (2011a, 6). Gender (being a woman/a man) functions in a similar fashion and provides “the principle of normative unity” that organizes, unifies and determines the roles of social individuals (Witt 2011a, 73). Due to this, gender is a uniessential property of social individuals.