JANET, PIERRE. - Physician and psychologist, nephew of Paul J., b. in Paris on 30 May 1859, d. there on 23 Feb. 1947. Director of the laboratory of psychopathology at the Salpêtrière Hospital (1890), he later taught experimental psychology at the Sorbonne (1893), then experimental and comparative psychology at the Collège de France. 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. set himself the task of elaborating an experimental psychology constructed with rigorous scientific method. He devoted particular attention to the study of pathological phenomena, seeking to discover the laws of psychological disintegration as manifested in abnormal states. This involved a weakening of the synthesizing activity of the subject, 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* (Paris 1889); *L'état mental des hystériques* (ibid. 1894); *Nécroses et idées fixes* (ibid. 1898); *De l'angoisse à l'extase* (ibid. 1927–28).