LA.METTRIE, JULIEN OFFRAY DE (1709-1751), one of the creators of the French illumination, and the earliest exponent of that system of materialism which was afterwards elaborated by Holbach and Cabanis, was born at St Malo on December 25,1709. After for some years studying theology in the Jansenist schools with the intention of entering the church, he suddenly changed his career and threw himself with characteristic energy into the profession of medicine. In 1733 he went to Leyden to study under Boerhaave, then in the zenith of his fame, and in 1742 returned to Paris, where he obtained the appointment of surgeon to the guards. During an attack of fever he made some observations on himself with reference to the action of quickened circulation upon thought, which led him to the conclusion that psychical phenomena were to be accounted for as the effects of organic changes in the brain and nervous system. This conclusion he worked out in his earliest philosophical work, the Histoire Naturelle de l'Ame, which appeared about 1745. So great was the outcry caused by its publication that Lamettrie was forced to betake himself to Leyden, where he developed his doctrines still more boldly and completely, and with great originality, in his books Homme Machine and Homme Plante, treatises based upon principles of the most consistently materialistic character. The ethics of these principles were worked out in the subsequent volumes, Discours sur le Bonheur, La Volupte, and L' Art de _____, in which the end of life is found in the pleasures of the senses, and virtue is reduced to self-love. So strong was the feeling against Lamettrie that in 1748 he was compelled to quit Holland for Berlin, where Frederick the Great not only allowed him to practise as a physician, but appointed him court reader. He died in 1751, when his position as a philosopher was publicly recognized in an address written by the king himself, and read before the Berlin Academy. His collected Oeuvres Philosophiques appeared after his death in several editions, published in London, Berlin, and Amsterdam respectively. The best account of his system is that given in A. Lange's Geschichte des Materialismus.