Pierre Marie Félix Janet (1859-1947) was a French psychologist particularly well known for his work on psychopathology and psychotherapy.

Born in Paris on May 28, 1859, Pierre Janet spent his childhood and youth in that city. His bent for natural sciences led him to pursue studies in physiology at the Sorbonne at the same time that he was studying philosophy, for which he received a master's degree in 1882. Janet then left Paris for Le Havre and for 7 years taught philosophy there in the lycée.

Janet, however, wanted to study medicine and at the hospital of Le Havre began to do research in hypnosis, using the well-known medium Léonie. Through these studies, the first of this sort, Janet came into contact with Jean Martin Charcot, but after reading Charcot and Hippolyte Bernheim he thought these investigators did not sufficiently take into consideration the psychological factors...