After a two-year period of preparation (Khâgne) under Jean Guitton at the Lycée du Parc, Althusser was admitted into the ENS in July 1939. But his attendance was deferred by many years because he was drafted into the French Army in September of that year in the run-up to World War II and, like most French soldiers following the Fall of France, was captured by the Germans. Seized in Vannes in June 1940, he was held in a prisoner-of-war camp in Schleswig-Holstein, in Northern Germany, for the five remaining years of the war. In the camp, he was at first drafted to hard labour but ultimately reassigned to work in the infirmary after falling ill. This second occupation allowed him to read philosophy and literature. In his memoirs, Althusser described the experiences of solidarity, political action, and community in the camp as the moment he first understood the idea of communism. Althusser recalled: "It was in prison camp that I first heard Marxism discussed by a Parisian lawyer in transit—and that I actually met a communist". His experience in the camp also affected his lifelong bouts of mental instability, reflected in constant depression that lasted until the end of life. Psychoanalyst Élisabeth Roudinesco has argued that the absurd war experience was essential for Althusser's philosophical thought.
After a two-year period of preparation (Khâgne) under Jean Guitton at the Lycée du Parc, Althusser was admitted into the ENS in July 1939. But his attendance was deferred by many years because he was drafted into the French Army in September of that year in the run-up to World War II and, like most French soldiers following the Fall of France, was captured by the Germans. Seized in Vannes in June 1940, he was held in a prisoner-of-war camp in Schleswig-Holstein, in Northern Germany for the five remaining years of the war. In the camp, he was at first drafted to hard labour but ultimately reassigned to work in the infirmary after falling ill. This second occupation allowed him to read philosophy and literature. In his memoirs, Althusser described the experiences of solidarity, political action, and community in the camp as the moment he first understood the idea of communism. Althusser recalled: "It was in prison camp that I first heard Marxism discussed by a Parisian lawyer in transit—and that I actually met a communist". His experience in the camp also affected his lifelong bouts of mental instability, reflected in constant depression that lasted until the end of life Psychoanalyst Élisabeth Roudinesco has argued that the absurd war experience was essential for Althusser's philosophical thought.