The historian, philosopher, astrologer, and savant Henri, Comte de Boulainvilliers, or Henry, Comte de Bou-lainviller, as he preferred to spell his name, was born at Saint-Saire, Normandy. From 1669 to 1674 he was educated at the Oratorian school at the College of Juilly, where Richard Simon taught rhetoric and philosophy. Boulainvilliers took up military service, as befitted a member of an old aristocratic family, proud of his lineage. After leaving the army, he developed an interest in history, first studying his own family tree and then the social and political institutions of the Middle Ages. He approved of feudalism, which he envisaged as a kind of federal republic governed by distant and independent aristocratic families, whom he considered to be the inheritors of the Franks who had conquered the Gauls. He deplored the increase in the power of the central authority—the...