 At the end of the war and following his release from the P.O.W. camp in 1945, Althusser took his place at the ENS. Now 27 years old, he began the program of study that was to prepare him for the agrégation, the competitive examination which qualifies one to teach philosophy in French secondary schools and that is often the gateway to doctoral study and university employment. Perhaps not surprisingly for a young man who had just spent half a decade in a prison camp, much happened during the three years he spent preparing for the exam and working on his Master’s thesis. Though still involved in Catholic groups and still seeing himself as a Christian, the movements that Althusser associated with after the war were leftist in their politics and, intellectually, he made a move to embrace and synthesize Christian and Marxist thought. This synthesis and his first published works were informed by a reading of 19th Century German idealist philosophy, especially Hegel and Marx, as well as by progressive Christian thinkers associated with the group Jeunesse de l’Église. Indeed, it was 19th Century German Idealism with which he was most engaged during his period of study at the ENS. In line with this interest (one shared with many other French intellectuals at the time), Althusser obtained his diplôme d’études supérieures in 1947 for a work directed by Gaston Bachelard and titled “On Content in the Thought of G.W.F. Hegel.” In 1948, he passed his agrégation, coming in first on the written portion of the exam and second on the oral. After this showing, Althusser was offered and accepted the post of agrégé répétiteur (director of studies) at the ENS whose responsibility it was to help students prepare for their own agrégations. In this capacity, he began offering courses and tutorials on particular topics in philosophy and on particular figures from the history of philosophy. As he retained this responsibility for more than thirty years and worked with some of the brightest thinkers that France produced during this time (including Alain Badiou, Pierre Bourdieu, and Michel Foucault), through his teaching Althusser left a deep and lasting impression on a generation of French philosophers and on French philosophy.