Pierre Janet

Educated in philosophy at the École Normale Supérieure and in medicine under Charcot at the Salpêtrière, Janet investigated psychological automatism and hysteria. In his 1889 doctoral thesis L'Automatisme psychologique, he introduced the concept of the subconscious ('le subconscient') and psychological dissociation.

In his landmark studies of psychological trauma and neurosis (L'État mental des hystériques, 1893), Janet demonstrated that traumatic memories can be split off from conscious awareness into fixed subconscious sub-systems, directly anticipating modern trauma therapy. He served as professor of experimental psychology at the Collège de France from 1902 to 1934.