Paul-Henri Thiry, Baron d'Holbach (French: [dɔlbak]) (8 December 1723 – 21 January 1789), was a French-German philosopher, encyclopedist, writer, and prominent figure in the French Enlightenment. He was born Paul Heinrich Dietrich in Edesheim, near Landau in the Rhenish Palatinate, but lived and worked mainly in Paris, where he kept a salon. He was well known for his atheism and for his voluminous writings against religion, the most famous of them being The System of Nature (1770).
Later in 1754, when he learnt that Mme d'Holbach had died,Later in 1754, when he learnt that Mme d'Holbach had died,[note 1] Rousseau wrote a tender condolence letter to d'Holbach, and the friendship between the two men was rekindled. For three more years, Rousseau would frequent the salon of d'Holbach.
D'Holbach later arranged, along with Grimm and Diderot, for an annuity of 400 livres for Rousseau's common-law wife Thérèse Levasseur and her mother, pledging them not to reveal this to Rousseau for fear of wounding Rousseau's pride. When Rousseau eventually found out about this, he was furious with his friends for humiliating him. [note 2]
According to Marmontel, d'Holbach "had read everything and never forgotten anything of interest." Jean-Jacques Rousseau commented that d'Holbach could hold his own among scholars since he was learned and knowledgeable. Diderot enthusiastically endorsed d'Holbach's book System of Nature.
D'Holbach's philosophy influenced Marat, Danton, and Camille Desmoulins. According to Faguet: "d'Holbach, more than
D'Holbach's philosophy influenced Marat, Danton, and Camille Desmoulins. According to Faguet: "d'Holbach, more than Voltaire, more than Diderot, is the father of all the philosophy and all the anti-religious polemics at the end of the eighteenth and the first half of the nineteenth century."
During the French Directory, a book of d'Holbach was circulated to all departmental heads in a bid to rein in religious revivalism. In England, d'Holbach's views influenced Priestly, Godwin, and Shelley. In Germany, d'Holbach's views influenced Immanuel Kant.[note 3] It is speculated that d'Holbach's views influenced the historical materialism of Karl Marx.