John Locke (1632–1704) was a 17th-century philosopher concerned primarily with society and epistemology. An Englishman, Locke's notions of a "government with the consent of the governed" and man's natural rights—life, liberty, and estate (property)—had an enormous influence on the development of political philosophy. His ideas formed the basis for the concepts used in American law and government, allowing the colonists to justify revolution. Locke's epistemology and philosophy of mind also had a great deal of significant influence well into the Enlightenment period. Locke has been placed in a group called the British Empiricists, which includes David Hume and George Berkeley. Locke is perhaps most often contrasted with Thomas Hobbes. (from Wikipedia.com) Locke's work includes Two Treatises of Government (1689), A Letter Concerning Toleration (1689), and An Essay Concerning Human Understanding (1689).