Of all post-structural thought, perhaps the greatest influence on historians has come from the work of French thinker Michel Foucault (1926–84). Like Derrida, he was trained in philosophy rather than literature, but his work reflected a constant attention to not only the creation and transmission of meaning, but also in the social and discursive systems that enable this cultural process.16 Foucault's early career included positions in several European institutions and also at an African university. In the course of his travels he rummaged through a variety of libraries and archives, developing a thorough and thoroughly idiosyncratic historical expertise, as well as spending time in psychiatric and medical hospitals, observing treatment. His work drew on all these experiences, but it has been roundly criticized for historical inaccuracies. From 1970 he held the chair of Professor of the History of Systems of Thought at the Collège de France and also lectured widely in other countries. His historical studies (though he always resisted the title of historian) included works on the transformation of natural history and economics (The Order of Things, 1966; translated 1970) and of the medical profession (The Birth of the Clinic, 1963; translated 1973); an analysis of the transformation of prisons in the eighteenth and nineteenth centuries (Discipline and Punish, 1975; translated 1977); and an ambitious history of sexuality (multiple volumes, 1976–84). Foucault developed a distinctive form of discourse analysis and a controversial notion of radical “epistemic” breaks at certain transitional moments in history – moments in which new discursive formations enabled new expressions of knowledge or belief. These apparently “agentless” breaks, in accordance with his relegation of the author to a function, seemed to remove autonomous, individual actors from the historical field; yet, as critics noted, Foucault himself relied on authorial actors, great thinkers as well as obscure ones, for the texts he excavated in his “archaeologies” of the past. In The Archaeology of Knowledge (1969; translated 1972), Foucault articulated a theory and praxis of post-structural historical inquiry, stressing that knowledge is a construction of culture and language rather than an objective, transparent reflection of stable realities.