Theory in psychology is notoriously ahistorical in its formal expression, mimicking a version of the established sciences. The nature of human psychological phenomena however belies this ahistorical stance. Psychological "objects" are deeply embedded in historical and social norms. As historians of the discipline have reminded us so often, they are linguistic categories whose reference is always imprecise, shifting, and changing with the communities that use them. In this paper we examine this anew by taking up psychology's ambivalent historical relationship to women, feminism, and gendered psychological categories. Since its inception in the late 1960s, feminist psychology has sometimes drawn upon historical studies and made historical arguments to advance theoretical claims about sex and gender. Although arguably sensitive to context, which after all is a central principle of a feminist psychology, only some feminist theorizing specifically includes a historical context. Furthermore, the theorizing of sex and gender outside of a feminist perspective within psychology virtually never incorporates a historical consciousness. We trace how history and theory have been combined in feminist theorizing of the late twentieth century and into the twenty-first century. In the process, we attempt to recoup the lessons of how "difference" figures in psychological theory.