(born June 28, 1712, Geneva, Switz.died July 2, 1778, Ermenonville, France) Swiss-French philosopher. At age 16 he fled Geneva to Savoy, where he became the steward and later the lover of the baronne de Warens. At age 30, having furthered his education and social position under her influence, he moved to Paris, where he joined Denis Diderot at the centre of the philosophes; he wrote on music and economics for Diderot's Encyclopédie. His first major work, the Discourse on the Arts and Sciences (1750), argued that man is good by nature but has been corrupted by society and civilization; Rousseau's belief in the natural goodness of man set him apart from Roman Catholic writers who, like him, were hostile to the idea of progress. He also wrote music; his light opera The Cunning-Man (1752) was widely admired. In 1752 he became involved in an influential dispute with Jean-Philippe Rameau over the relative merits of French and Italian music; Rousseau championed the latter. In the Discourse on the Origin and Foundations of Inequality Among Men (1754), he argued against Thomas Hobbes that human life before the formation of societies was healthy, happy, and free and that vice arose as the result of social organization and especially the introduction of private property. Civil society, he held, comes into being only to ensure peace and to protect property, which not everyone has; it thus represents a fraudulent social contract that reinforces inequality. In the Social Contract (1762), which begins with the memorable line, Man was born free, but he is everywhere in chains, Rousseau argues that a civil society based on a genuine social contract rather than a fraudulent one would provide people with a better kind of freedom in exchange for their natural independence, namely, political liberty, which he understands as obedience to a self-imposed law created by the general will. In 1762 the publication of Émile, a treatise on education, produced outrage, and Rousseau was forced to flee to Switzerland. He began showing signs of mental instability c. 1767, and he died insane. His Confessions (1781–88), which he modeled on the work of the same title by St. Augustine, is among the most famous autobiographies.