Let us begin, however, with a sketch of the philosophical environment in which Foucault was educated. He entered the École Normale Supérieure (the standard launching pad for major French philosophers) in 1946, during the heyday of existential phenomenology. Merleau-Ponty, whose lectures he attended, and Heidegger were particularly important. Hegel and Marx were also major concerns, the first through the interpretation of his work offered by Jean Hyppolite and the latter through the structuralist reading of Louis Althusser—both teachers who had a strong impact on Foucault at the École Normale. It is, accordingly, not surprising that Foucault's earliest works (his long “Introduction” to Dream and Existence by Ludwig Binswanger, a Heideggerian psychiatrist, and Maladie mentale et personalité, a short book on mental illness) were written in the grip of, respectively, existentialism and Marxism. But he soon turned away quite decisively from both.
Although Jean-Paul Sartre, living and working outside the University system, had no personal influence on Foucault, the thought of him, as the French master-thinker preceding Foucault, is always in the background. Like Sartre, Foucault began from a relentless hatred of bourgeois society and culture and with a spontaneous sympathy for groups at the margins of the bourgeoisie (artists, homosexuals, prisoners, etc.). They were also similar in their interests in literature and psychology, as well as philosophy, and both, after an early relative lack of political interest, became strong activists. But in the end, Foucault seemed to insist on defining himself in contradiction to Sartre. Philosophically, he rejected what he saw as Sartre's centralization of the subject (which he mocked as “transcendental narcissism”). Personally and politically, he rejected Sartre's role as what Foucault called the “universal intellectual”, judging a society in terms of transcendent principles. There is, however, a tincture of protesting too much in Foucault's separation of himself from Sartre, and the question of the relation of their work remains a fertile one.
Three other factors were of much more positive significance for the young Foucault. First, there was the French tradition of history and philosophy of science, particularly as represented by Georges Canguilhem, a powerful figure in the French University establishment, whose work in the history and philosophy of biology provided a model for much of what Foucault was later to do in the history of the human sciences. Canguilhem sponsored Foucault's doctoral thesis on the history of madness and, throughout Foucault's career, remained one of his most important and effective supporters. Canguilhem's approach to the history of science (an approach developed from the work of Gaston Bachelard), provided Foucault with a strong sense (Kuhnian avant la lettre) of the discontinuities in scientific history, along with a “rationalist” understanding of the historical role of concepts that made them independent of the phenomenologists' transcendental consciousness. Foucault found this understanding reinforced in the structuralist linguistics and psychology developed, respectively, by Ferdinand de Saussure and Jacques Lacan, as well as in Georges Dumézil's proto-structuralist work on comparative religion. These anti-subjective standpoints provide the context for Foucault's marginalization of the subject in his “structuralist histories”, The Birth of the Clinic (on the origins of modern medicine) and The Order of Things (on the origins of the modern human sciences).
In a quite different vein, Foucault was enthralled by French avant-garde literature, especially the writings of Georges Bataille and Maurice Blanchot, where he found the experiential concreteness of existential phenomenology without what he came to see as dubious philosophical assumptions about subjectivity. Of particular interest was this literature's evocation of “limit-experiences”, which push us to extremes where conventional categories of intelligibility begin to break down.
This philosophical milieu provided materials for the critique of subjectivity and the corresponding “archaeological” and “genealogical” methods of writing history that inform Foucault's projects of historical critique, to which we now turn.