Foucault brings up the possible objection that though there has been an increase in discourse on sex, this discourse has been directed at reducing non- reproductive sexual practices and rendering sex economically useful and politically conservative. Foucault replies that modern discourse has certainly not reduced the forms of non-reproductive sexual practices: on the contrary, this era has seen a multiplication of different kinds of sexual "perversion."
While discourse on sex had previously dealt solely with marriage—what one could and could not do within and without the bonds of marriage—discourse on sex came increasingly to focus on those who fell outside the category of marriage: children, homosexuals, the mentally ill, and so on. A distinction arose between violations of marriage bonds, which were seen as violations of the law, and violations of what was considered natural practice, which were seen as sick or demented.
Since the 18th century, there has been a concerted effort to distinguish and classify various non-marital sexual practices. The power exerted in making these distinctions, however, is not directed toward repressing these practices. Foucault identifies four operations involved in this exertion of power, all of which are directed more toward proliferating sexual "perversion."
First, Foucault identifies a very different motive than simple repression at work in the study of child sexuality. The scrutiny of children's sexuality effectively serves as a launching pad for a more general examination of sexuality. It alerts parents, teachers, and doctors to the dangers of child sexuality, and traces the origins of child sexuality in family relationships. What is made to seem like a boundary—excluding children from the realm of sexuality—is essentially a means to expand the study of sexuality to a number of different realms.
Second, Foucault sees the modern concept of homosexuality arising from a desire to see sexuality as a fundamental aspect of who we are. Before the 19th century, sodomy was simply regarded as a criminal act. Since the 19th century, sodomy has been regarded as just one manifestation of a person's homosexuality. "Homosexuality" ceased to be associated with certain acts, and became associated with a person's identity, with his soul. One's sexuality became a key to interpreting one's personality and one's behavior. Rather than work to eliminate homosexual acts, the growing discourse around homosexuality saw these acts as constitutive of a person's identity.
Third, Foucault sees the increased scrutiny on different forms of sexual behavior as part of what he calls "spirals of power and pleasure." The close scrutiny that accompanies the "medicalization of sexuality" draws observer and observed into intimate contact. On one hand, the observer exercises power in examining and drawing out his subject's sexual pleasures, and this exercise of power gives him a kind of pleasure. On the other hand, the observer's scrutiny isolates and highlights his subject's pleasures, thus encouraging them. Both observer and observed find power and pleasure intermingled in this intimate game of examination.