Foucault’s first canonical monograph, in the sense of a work that he never repudiated, was his 1961 primary doctoral thesis, Madness and Unreason: A History of Madness in the Classical Age , which has ultimately come to be known simply as the History of Madness . It is best known in the English-speaking world by an abridged version, Madness and Civilization , since for decades the latter was the only version available in English . History of Madness is a work of some originality, showing several influences, but not slavishly following any convention. It resembles Friedrich Nietzsche ’s Birth of Tragedy in style and form (thought greatly exceeding it in length), proposing a disjunction between reason and unreason similar to Nietzsche’s Apollonian/Dionysian distinction. It also bears the influence of French history and philosophy of science, the most prominent twentieth century representative of which was Gaston Bachelard, the developer of a notion of “epistemological rupture” to which most of Foucault’s works are indebted. Yet Georges Canguilhem’s focus on the division of the normal from the pathological is perhaps the most telling influence on Foucault in this book. Foucault’s thought continues moreover to owe something to Marxism and to social history more generally, constituting an historical analysis of social divisions.