Foucault's constructivist understanding that sexuality is an effect of the discursive operations of power underwrites Gayle Rubin's important essay "Thinking Sex." Often identified as one of queer theory's foundational texts, Rubin's essay follows Foucault's rejection of libidinal or biological explanations of sexuality in order to think about the way in which sexual identities and behaviors are hierarchically organized through systems of sexual stratification. Calling for the recognition of "the political dimensions of erotic life," Rubin demonstrates the way in which certain forms of sexual expression are valorized over others, licensing the persecution of those who fall outside the narrow frame of what constitutes sexual legitimacy (p. 35). As part of her project of specifying the regulation and stratification of sexuality, Rubin argues against the feminist assumption that "sexuality is a derivation of gender" (p. 33). While she acknowledges that gender relations have been an important context for the articulation of the sexual system, she argues that sex and gender are not synonymous, and hence the rubric of gender cannot account for sexuality in its entirety. Rubin's critical interest in sexual variation that exceeds any hetero-homo differentiation demands "an autonomous theory and politics specific to sexuality" (p. 34).