Originally intended to dispute the biology-is-destiny formulation, the distinction between sex and gender serves the argument that whatever biological intractability sex appears to have, gender is culturally constructed: hence, gender is neither the causal result of sex nor as seemingly fixed as sex. The unity of the subject is thus already potentially contested by the distinction that permits of gender as a multiple interpretation of sex.
If gender is the cultural meanings that the sexed body assumes, then a gender cannot be said to follow from a sex in anyone way. Taken to its logical limit, the sex/gender distinction suggests a radical discontinuity between sexed bodies and culturally constructed genders. Assuming for the moment the stability of binary sex, it does not follow that the construction of “men” will accrue exclusively to the bodies of males or that “women” will interpret only female bodies. Further, even if the sexes appear to be unproblematically binary in their morphology and constitution (which will become a question), there is no reason to assume that genders ought also to remain as two. The presumption of a binary gender system implicitly retains the belief in a mimetic relation of gender to sex whereby gender mirrors sex or is otherwise restricted by it. When the constructed status of gender is theorized as radically independent of sex, gender itself owes a free-floating artifice, with the consequence that man and masculine might just as easily signify a female body as a male one, and woman and feminine a male body as easily as a female one.
This radical splitting of the gendered subject poses yet another set of problems. Can we refer to a “given” sex or a “given” gender without first inquiring into how sex and/or gender is given, through what means? And what is “sex” anyway? Is it natural, anatomical, chromosomal, or hormonal, and how is a feminist critic to assess the scientific discourses which purport to establish such “facts” for us? Does sex have a history? Does each sex have a different history, or histories? Is there a history of how the duality of sex was established, a genealogy that might expose the binary options as a variable construction? Are the ostensibly natural facts of sex discursively produced by various scientific discourses in the service of other political and social interests? If the immutable character of sex is contested, perhaps this construct called “sex” is as culturally constructed as gender; indeed, perhaps it was always already gender, with the consequence that the distinction between sex and gender turns out to be no distincton at all.
It would make no sense, then, to define gender as the cultural interpretation of sex, if sex itself is a gendered category. Gender ought not to be conceived merely as the cultural inscription of meaning on a pregiven sex (a juridical conception); gender must also designate the very apparatus of production whereby the sexes themselves are established. As a result, gender is not to culture as sex is to nature; gender is also the discursive/cultural means by which “sexed nature” or “a natural sex” is produced and established as “prediscursive,” prior to culture, a politically neutral surface on which culture acts. This construction of “sex” as the radically unconstructed will concern us again in the discussion of Levi-Strauss and structuralism in chapter 2. At this juncture it is already clear that one way the internal stability and binary frame for sex is effectively secured is by casting the duality of sex in a prediscursive domain. This production of sex as the prediscursive ought to be understood as the effect of the apparatus of cultural construction designated by gender.
Judith Butler, Gender Trouble, pp 9-11