At the end of the Middle Ages, leprosy disappeared from the Western world. In the margins of the community, at the gates of cities, there stretched wastelands which sickness had ceased to haunt but had left sterile and long uninhabitable.
This quotation comes from the very beginning of Madness and Civilization, and shows an important social and cultural shift in the status of madness. Leprosy played a particular role in European consciousness, and its disappearance is a physical and mental phenomenon. The leper was excluded from "normal" society; and, by excluding him, society defined itself. The abnormal and frightening was excluded, and the healthy and safe was accepted. Leprosy existed in a particular "space" within society. This space was both real and imaginary; buildings were created to house the excluded lepers, but they also existed in a certain cultural space on the edge of the normal community. The "wastelands" that Foucault describes are partly a creation of the mind; they were eventually repopulated by madmen, who replaced the lepers as an excluded class. Madness does not resemble leprosy, but in a way Foucault believes that it occupies the same place in society.