German-born French intellectual. Paul Heinrich Dietrich took the name and French nationality of his maternal uncle, who had made a fortune in Paris. For many years Holbach's salon in Paris was the central meeting-point of many of the thinkers of the French Enlightenment. His own philosophical stance was one of unswerving atheistic materialism, and he took pains to demonstrate that this is compatible with a life of altruism and virtue. His most important philosophical work was the Système de la nature (1770, trs. as The System of Nature, 1795).