The interesting but largely obscure Boulanger was a regular member of d’Holbach’s salon. He wrote articles for Diderot and d’Alembert’s Encyclopédie; Diderot and d’Holbach published his works posthumously. His letters to Helvetius (a friend), either initialled or signed pseudonymously, were long thought to be from a better-known associate, Voltaire for example attributing them to Diderot.