John Locke

John Locke's influence on the Enlightenment and on western thought encompassed philosophy, government, politics, religion, and what is now called psychology. Like Descartes, Locke was interested in the problem of epistemology: how we know things. But Locke did not believe in innate ideas or intuition. He argued that all ideas are based on sense experience; this approach he called "empiricism." His Essay Concerning Human Understanding (1690) tried to show that every branch of human knowledge--including religion--is based on experience and reflection. Locke had grown up during the Thirty Years' War, and also experienced religious turmoil in England. He concluded that religious questions cannot be solved by war. In his Letters Concerning Toleration he argued that religion is a matter of individual conscience; therefore it can only win converts through persuasion, never by force. Liberty of conscience is the "natural right" of each human being. Government must recognize this and not interfere in religion. Toleration, not war, is the way to manage religious conflicts. Locke's toleration was limited to various forms of Protestantism; nevertheless it helped set a direction toward a broader strategy of pluralism. Americans adapted Locke's ideas and applied them to the constitutional settlement guaranteeing religious freedom.