“Subjectivity” and its cognates are philosophical terms that describe a possibility for lived experience within a larger historical and political context. “The subject” (le sujet) is not simply a synonym for “person”; instead the term captures the possibility of being a certain kind of person, which, for the theorists who tend to use it, is typically a contingent historical possibility rather than a universal or essential truth about human nature. These terms are especially philosophically important for Michel Foucault, who, in his middle works Discipline and Punish and The History of Sexuality, Volume I, develops a theoretical-historical account of the emergence of the modern subject in the context of what he calls “disciplinary power”. This chapter draws on these texts to elaborate how Foucault believes such subjects come into being and what the implications are for us: the persons who, he argues, have inherited a system of power that both creates our possibilities and constrains our existence. I examine two related challenges to Foucault's account, and then conclude by drawing on contemporary discourses of weight and weight loss to show how his work can be applied to case studies beyond those Foucault himself discussed.

In French, the key term Foucault uses to capture the emergence of subjectivities (or subject-positions: particular spaces for being a subject) is assujettissement.