D'Holbach used his wealth to establish a coterie in Paris for which he became famous. This group included noted intellectuals of the day such as Denis Diderot, Claude-Adrien Helvetius, Jean-Jacques Rousseau, Benjamin Franklin, Edward Gibbon, David Hume, and Adam Smith, as well as French nobles and ambassadors from European countries.
D'Holbach contributed articles on chemistry and allied scientific topics to Diderot's ENCYCLOPEDIE. A vigorous opponent of Christianity, he escaped public and political ridicule by publishing his critical views using the names of deceased friends or employing pseudonyms. In 1761 he published LE CHRISTIANISME DEVOILE (Christianity Unveiled) using the name of his deceased friend N.A. Boulanger. His most famous book, SYSTEME DE LA NATURE (The System of Nature), published in 1770 under the name of J.B. Mirabaud, derided religion. LE BON-SENS (Good Sense) was published in 1772 under the name of Jean Meslier. D'Holbach's 1773 SYSTEME SOCIAL (Social System) placed morality and politics in a utilitarian framework. THE SYSTEM OF NATURE and GOOD SENSE were condemned by the Paris parliament and publicly burned.
D'Holbach died on June 21, 1789, in Paris.