In this work, Henry Vyverberg traces the evolution and consequences of a crucial idea in French Enlightenment thought--the idea of human nature. Human nature was commonly seen as a broadly universal, unchanging entity, though perhaps modifiable by geographical, social, and historical factors. Enlightenment empiricism suggested a degree of cultural diversity that has often been underestimated in studies of the age. Evidence here is drawn from Diderot's celebrated Encyclopedia and from a vast range of writing by such Enlightenment notables as Voltaire, Rousseau, and d'Holbach....