John Locke (1632-1704) is a predominant figure in the history of political theory and philosophy. His most extensive work, An Essay Concerning Human Understanding (1690), formalized empiricism, a branch of inquiry which focuses on the experience of the sense to gather knowledge, rather than speculation or intellectual deduction. Locke's concept of the tabula rasa the notion that people are born blank, with no knowledge or faults, remains a hugely influential philosophical concept. Much Enlightenment philosophy is based on Locke's writings, particularly his adherence to rationality and his refutation of the importance of innate personal traits in favor of experience in shaping personality.
John Locke published his Two Treatises of Government anonymously in 1690. Two years earlier, in 1688, the very unpopular King James II had been ousted in favor of King William the III and his wife Queen Mary in the Glorious Revolution, with the help of a group of wealthy noblemen known as the Whigs. Locke, though not living in England at the time of the Glorious Revolution (which had some claim to its name, having been almost entirely bloodless and peaceful) had strong associations with the Whigs, and sought to justify the ascension of King William (in fact, the Second Treatise was written to justify resistance to king Charles II, but was published as a defense of William's Revolution). The Treatises were written with this specific aim--to defend the Glorious Revolution. Locke also sought to refute the pro-Absolutist theories of Sir Robert Filmer, which he and his Whig associates felt were getting far too popular. Although not as immediate a challenge, Locke's work also serves as a major counter-argument to Thomas Hobbes' Leviathan, in which Hobbes argues in favor of absolutist government to keep people from abusing property and privacy. Many persistent rifts in political theory today stem from the fundamental disagreements between Locke's Second Treatise and Hobbes' Leviathan.
The Second Treatise of Government, subtitled An Essay Concerning the True Original Extent and End of Civil Government, stands today as an extremely influential work that shaped political philosophy and provided a basis for later political doctrines, such as those set forth in the Declaration of Independence and the United States Constitution.