Pierre Janet (pyĕr zhänā´), 1859–1947, French physician and psychologist. As director (1890–98) of the laboratory of pathological psychology at Salpêtrière and as professor of experimental and comparative psychology at the Collège de France from 1902, he made important contributions to the knowledge of mental pathology and the origins of hysteria through the use of hypnosis. In 1904 he founded the Journal de psychologie normal et pathologique, to which he contributed numerous articles. Among his important works were L'Automatisme psychologique (1889), in which he founded automatic psychology, and Les Obsessions et la psychasthénie (1903), which contains the first description of psychasthenia. Major Symptoms of Hysteria (1907) contains lectures delivered at Harvard. He wrote also Principles of Psychotherapy (1924), Psychological Healing (1925), and Cours sur l'amour et la haine (1933).