For Foucault, power and knowledge are not seen as independent entities but are inextricably related—knowledge is always an exercise of power and power always a function of knowledge. Perhaps his most famous example of a practice of power/knowledge is that of the confession, as outlined in History of Sexuality. Once solely a practice of the Christian Church, Foucault argues that it became diffused into secular culture (and especially psychology) in the eighteenth and nineteenth centuries. Through the confession (a form of power) people were incited to “tell the truth” (produce knowledge) about their sexual desires, emotions, and dispositions. Through these confessions, the idea of a sexual identity at the core of the self came into existence (again, a form of knowledge), an identity that had to be monitored, cultivated, and often controlled (again, back to power). It is important to note that Foucault understood power/knowledge as productive as well as constraining. Power/knowledge not only limits what we can do, but also opens up new ways of acting and thinking about ourselves.