JANET, PIERRE. - Physiologist and psychologist, nephew of Paul J., b. in Parigi on 30 May 1859, d. there on 23 Febr. 1947. Director of the laboratory of psychopathology at the Salpêtrière Hospital (1890), he subsequently taught experimental psychology at the Sorbona (1893), then experimental and comparative psychology at the Collegio di Francia. With G. Dumas he founded the Journal de psychologie normale et pathologique (1904). From 1913 he was a member of the Académie des sciences morales.
J. undertook the development of an experimental psychology constructed according to rigorous scientific method. He was particularly concerned with the study of pathological phenomena, attempting to discover the laws of psychological disintegration occurring in abnormal states. This would consist in a weakening of the subject’s synthesizing activity, supplanted by the formation of subgroups of psychic phenomena, disconnected from one another; hence the illusion of a plurality of consciousnesses. Such mental disintegration does not affect the ontological unity of the subject.
Principal works: L'automatisme psychologique (Parigi 1889); L'état mental des hystériques (ibid. 1894); Névros et idées fixes (ibid. 1898); De l'angoisse à l'extase (ibid. 1927-28).