DENIS DIDEROT, one of the thinkers whose pens overthrew the Bourbon monarchy in France, was born at Langres, October 5th, 1713. His father, who was a cutler by trade, gave him a classical education and put him in a lawyer’s office, where, instead of studying law, Diderot perfected himself in the modern languages and in literature. Quarreling with his father because of this, he was forced into literature as a profession. His first work was translating; but making the acquaintance of D’Alembert, they began together the great French Encyclopedia, the publication of which occupied more than twenty years. The Encyclopedia was chiefly his, and the most important work of his life was done in this connection; but he was also a voluminous writer of criticisms and essays. Catherine of Russia, who was fond of French philosophy until she saw that it threatened royalty, patronized Diderot, and he spent a year (1773–74) at her court. He died at Paris, July 30th, 1784.