Sigmund Freud developed a specific interest in hysteria after his stay with Professor Jean-Martin Charcot during the winter of 1885-1886, although his previous activity mainly consisted of neuropathology and general medical practice. Most of his initial studies on hysteria (hysteria in men, influence of subconscious ideas, role of traumas, and psychological and sexual factors) were indeed 'borrowed' from Charcot and his immediate followers, such as Pierre Janet and Paul Richer. Subsequently, Freud developed with Breuer a theory of hysteria which encompassed a mixture of Janet's 'fixed subconscious ideas' with the 'pathological secret' concept of Moriz Benedikt. After their book Studies on Hysteria (1895), Freud interrupted his collaboration with Breuer and developed the concept of conversion of psychological problems into somatic manifestations, with a strong 'sexualization' of hysteria. Firstly, he believed that actual abuses had occurred in these patients (the 'seduction' theory), but then blamed them for having deceived him on that issue, so that he subsequently launched a 'fantasy' theory to explain the development of hysterical symptoms without the necessity of actual abuses. Like many of his contemporaries, and contrary to his claims, Freud did not follow a scientific process of verified experiments, but rather adapted his theories to the evolution of his own beliefs on psychological conditions, selectively emphasizing the aspects of his 'therapies' with patients which supported his emerging ideas, with often abrupt changes in theoretical interpretations. While it remains difficult to get a clear, synthetic vision of what was Freud's definite theory of hysteria, it is obvious that hysteria really was the origin of what would become Freud's psychoanalytical theory. Indeed, psychoanalysis appears to have been initially developed by him largely in order to absorb and explain his many changes in the interpretation of hysterical manifestations.