The French physician and philosopher Julien Offray de La Mettrie (1709-1751) is best known for his "Man a Machine," an incisive and witty exposition of his theory of the dependence of mind on body.

The son of a tradesman, Julien de La Mettrie was born in Saint-Malo in Brittany on Dec. 25, 1709. Intended for the priesthood, he studied humanities at Coutances, rhetoric at Caen, and logic at the College of Plessis in Paris. At 15 he wrote an apologetic work on Jansenism. But this theological interest was short-lived, and in 1725 La Mettrie began 2 years of natural philosophy at the College of Harcourt. He received his degree in medicine at Rheims in 1728 and for the next 5 years practiced medicine in his native city.

In 1733 La Mettrie went to Leiden to study with the reknowned philosopher and physician Hermann Boerhaave. Soon La Mettrie was translating Boerhaave's works and adding his own observations--including...