René Descartes, often known by his Latin name, Renatus Cartesius, from which the adjective "Cartesian" is derived, was the prime mover behind the mechanistic conception of the human body. He was born the son of a wealthy magistrate in La Haye, Touraine, France. From 1606 to 1614, he studied logic, mathematics, scholastic theology, Aristotelian philosophy, and the classics at the Jesuit school of La Flèche in Anjou. In 1616, he took a law degree from the University of Poitiers, but never practiced law. Dissatisfied with his education in France, he enrolled in the Dutch military academy at Breda in 1618. There he studied mathematics and mechanics under Isaac Beeckman (1588-1637), whom he acknowledged as his mentor.

Descartes served in the Thirty Years War, first in the Dutch army, then in the Bavarian army. Because of his chronic ill health, he did no fighting, but contributed his mathematical and engineering...