Paul-Henri Thiry, Baron d' Holbach, the foremost exponent of atheistic materialism and the most intransigent polemicist against religion in the Enlightenment, was born of honorable but obscure German parents in Edesheim, a small town in the Palatinate; his name was originally Paul Heinrich Dietrich. His upbringing and education were directed by his maternal uncle, Franciscus Adam d'Holbach, who had made a fortune in Paris and assumed French nationality. After studying at the University of Leiden, Holbach came to Paris, in 1749, married his second cousin Basile-Geneviève d'Aine, and soon became a French subject. On his uncle's death in 1753, he inherited the title of Baron d'Holbach, with properties yielding a handsome income of 60,000 livres. The following year his wife died, and in 1756 Holbach married her younger sister, Charlotte Suzanne d'Aine.

On settling in Paris, Holbach had associated...