JULIEN OFFRAY DE LAMETTRIE (1709-1751), French physician and philosopher, the earliest of the materialistic writers of the Illumination, was born at St Malo on the 25th of December 1709. After studying theology in the Jansenist schools for some years, he suddenly decided to adopt the profession of medicine. In 1733 he went to Leiden to study under Boerhaave, and in 1742 returned to Paris, where he obtained the appointment of surgeon to the guards. During an attack of fever he made 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'dme, which appeared about 1745. So great was the outcry caused by its publication that Lamettrie was forced to take refuge in Leiden, where he developed his doctrines still more boldly and completely, and with great originality, in L'Homme machine (Eng. trans., London, 1750; ed. with introd. and notes, J. Assezat, 1865), and L'Homme Plante, treatises based upon principles of the most consistently materialistic character. The ethics of these principles were worked out in Discours sur le bonheur, La Volupte, and L' Art de jouir, in which the end of life is found in the pleasures of the senses, and virtue is reduced to self-love. Atheism is the only means of ensuring the happiness of the world, which has been rendered impossible by the wars brought about by theologians. The soul is only the thinking part of the body, and with the body it passes away. When death comes, the farce is over ( la farce est jouee ), therefore let us take our pleasure while we can. Lamettrie has been called "the Aristippus of modern materialism." So strong was the feeling against him XVI. 5 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 on the 1 th of November 17 51. His collected Ouvres philosophiques appeared after his death in several editions, published in London, Berlin and Amsterdam respectively.
The chief authority for his life is the Eloge written by Frederick the Great (printed in Assezat's ed. of Homme machine). In modern times Lamettrie has been judged less severely; see F. A. Lange, Geschichte des Materialismus (Eng. trans. by E. C. Thomas, ii. 1880); Neree Quepat (i.e. Rene Paquet), La Mettrie, sa vie et ses oeuvres (1873, with complete history of his works); J. E. Poritzky, J. 0. de Lamettrie, Sein Leben and seine Werke (1900); F. Picavet, "La Mettrie et la critique allemande," in Compte rendu des seances de l'Acad. des Sciences morales et politiques, xxxii. (1889), a reply to German rehabilitations of Lamettrie.