Paul-Henri-Thiry d’Holbach was born in 1723 at Heidelsheim, in the Palatinate. His father, said Jean Jacques Rousseau when he had quarrelled with the son, was a _parvenu_. Another of Paul-Henri’s guests announced that his host was called Baron because he was ‘of German origin, had a small estate in Westphalia, and an income of sixty thousand livres.’ Very little is known with certainty of his family. He was brought up in Paris, and was from the first French of the French, Parisian of the Parisians. He seems to have visited Germany as a very young man, and to have studied natural science there. He made his bow to the literary world by translating German scientific works into French. At his death Grimm wrote in the ‘Literary Correspondence’ that the rapid progress natural history and chemistry had made for thirty years in France was largely owing to the Baron d’Holbach. As a young man the Baron was what he remained all his life--a compiler, an annotator, a transcriber, rather than the possessor of any great original talent of his own. Boy and man he had in perfection that gift which surely makes for human happiness more than any other single quality--a devoted love of learning. He was always rich enough to buy the books and the leisure to gratify that love. He lived in an age and in the midst of brilliantly accomplished men and women. He should have found life delightful. He did. A serene, easy, generous nature, troubled by no agitating ambitions, everything seems to have fallen out from the first according to his modest desires. For him, and for him alone among Voltaire’s co-operators, the path to light and knowledge flowered pleasantly all the way. The others look out eagerly from their portraits--furrowed foreheads and burning eyes--or with faces noble and sad, like d’Alembert or Condorcet. Only the good Baron is seated at his ease in his pleasant, sumptuous garden, surveying life calmly and leisurely. Which things are a parable. In 1752 or 1753, when he was about thirty years old, he began writing articles for that Encyclopædia which set on almost all its other contributors the ban of Government ill-favour. Only Paul-Henri--writing always judiciously under a pseudonym--gained nothing but pleasure and approbation from his excellent papers on mineralogy and chemistry. He formed the happiest life-long friendships with his fellow-writers in that immortal book. He married a pretty and charming wife, Mademoiselle d’Aine. She died, in August 1754, after a very brief married life. D’Holbach travelled abroad with Grimm for a while. In 1755, he obtained a special dispensation from the Pope, and married his deceased wife’s sister, Mademoiselle Charlotte-Suzanne d’Aine, and began to live with her a life which presented the very rare combination of perfect domestic contentment and the most brilliant social success.