In 1770, d'Holbach published his most famous book, "The System of Nature" ("Le Système de la nature"), under the name of Jean-Baptiste de Mirabaud, the secretary of the Académie française who had died ten years previously. Denying the existence of a deity, and refusing to admit as evidence all "a priori" arguments, d'Holbach saw the universe as nothing more than matter in motion, bound by inexorable natural laws of cause and effect. There is, he wrote "no necessity to have recourse to supernatural powers to account for the formation of things."