John Locke

Locke, John (1632–1704), English philosopher, founder of empiricism, whose writings helped initiate the European Enlightenment. His Essay Concerning Human Understanding (1690) opposed the view that there were innate ideas; he held instead that the human mind was like a blank slate on which knowledge is inscribed by experience. His Second Treatise of Civil Government (1690) established him as Britain's leading philosopher of politics. In it he argued that all people had the right to “life, health, liberty, and possessions.” He proposed a “social contract” to guarantee these rights. Locke also held that revolution was justified and even necessary in some circumstances, and he upheld both religious toleration and government by checks and balances, as later adopted in the U.S. Constitution. A believer in progress and the scientific method, Locke was one of the most influential thinkers of the modern era.