The English philosopher and political theorist John Locke (1632-1704) laid much of the groundwork for the Enlightenment and made central contributions to the development of liberalism. Trained in medicine, he was a key advocate of the empirical approaches of the Scientific Revolution. In his “Essay Concerning Human Understanding,” he advanced a theory of the self as a blank page, with knowledge and identity arising only from accumulated experience. His political theory of government by the consent of the governed as a means to protect the three natural rights of “life, liberty and estate” deeply influenced the United States’ founding documents. His essays on religious tolerance provided an early model for the separation of church and state.

John Locke’s Early Life and Education 

John Locke was born in 1632 in Wrighton, Somerset. His father was a lawyer and small landowner who had fought on the Parliamentarian side during the English Civil Wars of the 1640s. Using his wartime connections, he placed his son in the elite Westminster School.

Did you know? John Locke’s closest female friend was the philosopher Lady Damaris Cudworth Masham. Before she married the two had exchanged love poems, and on his return from exile, Locke moved into Lady Damaris and her husband’s household.

Between 1652 and 1667, John Locke was a student and then lecturer at Christ Church, Oxford, where he focused on the standard curriculum of logic, metaphysics and classics. He also studied medicine extensively and was an associate of Robert Hooke, Robert Boyle and other leading Oxford scientists.

John Locke and the Earl of Shaftesbury

In 1666 Locke met the parliamentarian Anthony Ashley Cooper, later the first Earl of Shaftesbury. The two struck up a friendship that blossomed into full patronage, and a year later Locke was appointed physician to Shaftesbury’s household. That year he supervised a dangerous liver operation on Shaftesbury that likely saved his patron’s life.

For the next two decades, Locke’s fortunes were tied to Shaftesbury, who was first a leading minister to Charles II and then a founder of the opposing Whig Party. Shaftesbury led the 1679 “exclusion” campaign to bar the Catholic duke of York (the future James II) from the royal succession. When that failed, Shaftesbury began to plot armed resistance and was forced to flee to Holland in 1682. Locke would follow his patron into exile a year later, returning only after the Glorious Revolution had placed the Protestant William III on the throne.

John Locke’s Publications 

During his decades of service to Shaftesbury, John Locke had been writing. In the six years following his return to England he published all of his most significant works.

Locke’s “Essay Concerning Human Understanding” (1689) outlined a theory of human knowledge, identity and selfhood that would be hugely influential to Enlightenment thinkers. To Locke, knowledge was not the discovery of anything either innate or outside of the individual, but simply the accumulation of “facts” derived from sensory experience. To discover truths beyond the realm of basic experience, Locke suggested an approach modeled on the rigorous methods of experimental science, and this approach greatly impacted the Scientific Revolution.

John Locke’s Views on Government

The “Two Treatises of Government” (1690) offered political theories developed and refined by Locke during his years at Shaftesbury’s side. Rejecting the divine right of kings, Locke said that societies form governments by mutual (and, in later generations, tacit) agreement. Thus, when a king loses the consent of the governed, a society may remove him—an approach quoted almost verbatim in Thomas Jefferson's 1776 Declaration of Independence. Locke also developed a definition of property as the product of a person’s labor that would be foundational for both Adam Smith’s capitalism and Karl Marx’s socialism. Locke famously wrote that man has three natural rights: life, liberty and property.

In his “Thoughts Concerning Education” (1693), Locke argued for a broadened syllabus and better treatment of students—ideas that were an enormous influence on Jean-Jacques Rousseau’s novel “Emile” (1762).

In three “Letters Concerning Toleration” (1689-92), Locke suggested that governments should respect freedom of religion except when the dissenting belief was a threat to public order. Atheists (whose oaths could not be trusted) and Catholics (who owed allegiance to an external ruler) were thus excluded from his scheme. Even within its limitations, Locke’s toleration did not argue that all (Protestant) beliefs were equally good or true, but simply that governments were not in a position to decide which one was correct.

John Locke’s Death

Locke spent his final 14 years in Essex at the home of Sir Francis Masham and his wife, the philosopher Lady Damaris Cudworth Masham. He died there on October 28, 1704, as Lady Damaris read to him from the Psalms.

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