La Mettrie, Julien Offray de

La Mettrie, Julien Offray de (1705-1751). French, Philosophy.

Inspired by René Descartes, John Locke, and his own observations as a physician, Julien La Mettrie became the first notable materialist of the eighteenth century, asserting only the physical realm has reality. The title of his most famous treatise proclaimed man a machine; as he put it in Le Système d’Epicure (1750): “. . . [nature] made without thinking a machine which thinks.” His outrageous ideas caused him to be reviled by prominent philosophes and opponents of the Enlightenment alike.

La Mettrie came from a village in the French province of Brittany. His father, a well-to-do textile merchant, provided him an excellent education, including five years of medical studies in Paris. In 1731 La Mettrie received a degree in medicine from the University of Reims. Subsequently he spent two years with the distinguished doctor Hermann Boerhaave, who taught at the University of Leyden in the Netherlands. From Boerhaave, Hermann, La Mettrie learned clinical practice and an understanding of anatomy and physiology were more significant than metaphysical speculations and scholarship for the cure of disease.

Returning home, La Mettrie became a translator and interpreter of Boerhaave’s works. He also began writing a series of cutting satires attacking prevailing medical practices and even individual doctors. These heavy-handed efforts to reform medicine and make it more responsive to public need earned him the reputation of being a traitor to his profession.

For a time La Mettrie was the personal physician of the Duke of Gramont and a doctor attached to a regiment of the French Guard. While on campaign during the War of the Austrian Succession he was afflicted with a fever and had occasion to mark the impact of his physical condition on his mental state. This insight led to his first philosophic work, L’Histoire naturelle de l’âme (1745), refuting the hypothesis of an immaterial, immortal soul. For him reason was superior to faith, and Aristotle was more true than Descartes when discussing the tangible world. Descartes distinguished animals from men by calling the former mindless machines and according the latter souls and reason. La Mettrie responded that beasts can also think and communicate their passions. Men, however, have no souls in the theological sense. The only difference between humans and animals lies in the complexity of their respective organic machinery. Locke was correct in viewing sensation as the source of mental processes, but he erred in supposing the mind possessed any independent faculty of reflection. The senses provide our only access to knowledge. What is called soul or mind is simply an aspect of one’s physical constitution and must be studied empirically as such.

Outrage over La Mettrie’s dismissal of man’s spirituality forced him into exile in the Netherlands, where he issued L’Homme machine (1747), a loosely-organized attempt to provide medical evidence for materialism. Here is his definitive statement that men, like animals, are automatons and that the physician, not the philosopher or the theologian, is best suited to reveal how men function. All human behavior, including reasoning, is based upon sensation and can be explicated strictly by reference to physiology, without supposing any divine intervention.

With that La Mettrie was no longer welcome among the Dutch, so he took refuge with King Fredrick the Great of Prussia, joining the Royal Academy of Berlin. In his remaining years La Mettrie wrote L’Homme plante (1748), adding botanical comparisons to his discussion of human nature; Le Système d’Epicure, proposing modern humans developed out of earlier, primitive creatures; and two essays on morality, Discours sur le bonheur (1748) and L’Art de jouir (1751), which argued indulging in sensual pleasures rather than practicing virtue led to happiness. La Mettrie saw virtue as an arbitrary concept, manufactured by society for self-preservation; he proposed society might be best served by more flexible moral standards.

La Mettrie died at the age of forty-one, reportedly from food poisoning. His enemies found his death appropriate for they accused him of being, among other things, a glutton.

La Mettrie’s materialism colored the writings of Diderot, Denis, Jean d’Alembert, Holbach, Paul Henri Dietrich, Baron d’, and the Sade, Marquis de. His ideas foreshadowed Marxism, Darwinism, and Freudianism. The conception of man as a machine led to Mary Shelley’s Frankenstein and its many literary descendants. Issues raised by La Mettrie’s theories continue to appear in discussions about cloning and genetic engineering.

Further Reading:

Kathleen Wellman, La Mettrie: Medicine, Philosophy, and Enlightenment, 1992.

Robert Luehrs