La Mettrie, Julien Offray de (zhülyăN' ôfrā' du lä metrē') [key], 1709–51, French physician and philosopher. On the basis of personal observation he claimed that psychical activity is purely the result of the organic construction of the brain and nervous system and developed this theory in Histoire naturelle de l'âme (1745). The protest against his atheistic materialism was so strong that La Mettrie had to leave the country. He further alienated the public with L'Homme machine (1748), the final development of his mechanical explanation of humans and the world. He lived in Berlin under the protection of his patron Frederick the Great. His ethics, purely hedonistic, are set forth in L'Art de jouir (1751).
