the work of 19th-century German philosopher Georg Wilhelm Friedrich Hegel. Hyppolite had devoted himself to uniting existentialist theories with the dialectical theories of Hegel and Karl Marx. These ideas influenced Foucault, who adopted Hyppolite's conviction that philosophy must develop through a study of history. University studies: 1946–1951 In autumn 1946, attaining excellent results, Foucault was admitted to the élite École Normale Supérieure (ENS), for which he undertook exams and an oral interrogation by Georges Canguilhem and Pierre-Maxime Schuhl to gain entry. Of the hundred students entering the ENS, Foucault ranked fourth based on his entry results, and encountered the highly competitive nature of the institution. Like most of his classmates, he lived in the school's communal dormitories on the Parisian Rue d'Ulm. He remained largely unpopular, spending much time alone, reading voraciously. His fellow students noted his love of violence and the macabre; he decorated his bedroom with images of torture and war drawn during the Napoleonic Wars by Spanish artist Francisco Goya, and on one occasion chased a classmate with a dagger. Prone to self-harm, in 1948 Foucault allegedly attempted suicide; his father sent him to see the psychiatrist Jean Delay at the Sainte-Anne Hospital Center. Obsessed with the idea of self-mutilation and suicide, Foucault attempted the latter several times in ensuing years, praising suicide in later writings. The ENS's doctor examined Foucault's state of mind, suggesting that his suicidal tendencies emerged from the distress surrounding his homosexuality, because same-sex sexual activity was socially taboo in France. At the time, Foucault engaged in homosexual activity with men whom he encountered in the underground Parisian gay scene, also indulging in drug use; according to biographer James Miller, he enjoyed the thrill and sense of danger that these activities offered him. Although studying various subjects, Foucault soon gravitated towards philosophy, reading not only Hegel and Marx but also Immanuel Kant, Edmund Husserl and most significantly, Martin Heidegger. He began reading the publications of philosopher Gaston Bachelard, taking a particular interest in his work exploring the history of science. He graduated from the ENS with a B.A. (licence) in Philosophy in 1948 and a DES (, roughly equivalent to an M.A.) in Philosophy in 1949. His DES thesis under the direction of Hyppolite was titled La Constitution d'un transcendental dans La Phénoménologie de l'esprit de Hegel (The Constitution of a Historical Transcendental in Hegel's Phenomenology of Spirit). In 1948, the philosopher Louis