Friedrich Nietzsche wrote On the Genealogy of Morals, a book that examined the historical evolution of morality. In this work, Nietzsche delegitimized the present by separating it from a cause-and-effect relationship with the past. His argument in On the Genealogy of Morals foreshadowed later schools of thought on moral relativity. This idea theorizes that there is no such concept as good or bad; all understandings of morality are based upon the social norms of a culture. When Michel Foucault first read Nietzsche’s work, he felt liberated from the prevailing French philosophy. Rather than viewing history through a collection of major events, each dependent on the one before it, both Nietzsche and Foucault were interested in smaller stories—those whose lives operated outside a grand narrative. Foucault was inspired to use an approach to studying history that would emphasize discontinuities and genealogies rather than connections.

When the Enlightenment brought the Age of Reason, it excluded certain groups of people from the conversation. Foucault was interested in those who lived outside of social norms; he was fascinated with the experiences of “the other.” In his first book, Madness and Civilization, Foucault argued that people with mental illness and disabilities lived decidedly better lives prior to the 18th century, when they were put into institutions and tucked away from public life.