Locke was born August 29, 1632, the oldest child of a respectable Somersetshire family of Puritan sympathies. His father was a lawyer, small landowner, and captain of a volunteer regiment in the parliamentary army. Locke's early education was carefully tended by his father at their rural home at Beluton, near Bristol; and it was probably through the influence of the elder Locke's parliamentary patrons that he obtained a place at Westminster School, where he remained from his fourteenth to his twentieth year. In 1652 he won a scholarship to Christ Church College, Oxford.
At the time Locke entered Oxford, Cromwell was chancellor, and the Puritans were in control. The curriculum, however, was still the traditional one of grammar, rhetoric, logic, geometry, and moral philosophy. Locke later declared that he "had lost a great deal of time at the commencement of his studies, because the only philosophy then known at Oxford was the Peripatetic," and his friend, Lady Masham, reported that he often told her that "he had so small satisfaction there from his studies ... that this discouragement kept him from being any very hard student." Nevertheless, after taking his bachelor's degree in 1656, he remained at Oxford to obtain his master's degree and then became successively lecturer in Greek, reader in rhetoric, and finally in 1664 censor of moral philosophy. But such activity did not fully occupy his attention. The reading of Descartes, which gave him "a relish of philosophical things," and the founding at Oxford of the Royal Society led him to begin experimenting in chemistry and meteorology. Soon afterwards he began the study of medicine and by 1666 he was engaged in occasional practice, although he never took a doctor's degree.
The common-place books kept between his twenty-eighth and thirty-fourth year show that it was also at Oxford that Locke became interested in political questions. His citations are concerned with such topics as the constitution of society, the relation of church and state, and the importance of religious toleration. In 1665 he interrupted his medical studies to serve on a diplomatic mission to Brandenburg. On his return he considered going to Spain as secretary of the embassy, although he eventually declined the offer. In 1667 he abandoned the academic life for the political world of London and "the society of great wits and ambitious politicians." This action came about largely as a result of an accidental meeting and ensuing friendship with Lord Ashley, Chancellor of the Exchequer, who persuaded Locke to enter his household as personal physician, general adviser, and confidant. For the next sixteen years Locke served his patron in various capacities. He saved Ashley's life by operating on an "imposthume in the breast," prescribed for the servants, helped to arrange the marriage of the eldest son, and drew up the "Fundamental Constitutions for the Government of Carolina," a colony of which Ashley was a "lord protector." When Ashley was made first Earl of Shaftesbury and Lord Chancellor in 1672, Locke became "secretary of presentations" and secretary of the council of trade.
Locke's many practical duties in London did not prevent him from pursuing his scientific and philosophical interests. His medical studies provided the basis for a close friendship with Sydenham, and Locke sometimes accompanied him on his professional calls. He kept up his early interest in chemistry with his friend, Robert Boyle, and upon the latter's death, edited his General History of the Air. He frequently held informal gatherings for the discussion of questions in science and theology. On one such occasion, when meeting with "five or six friends," a question arose concerning the "limits of human understanding." Locke undertook to provide an answer, and what was thus "begun by chance, was continued by entreaty, written by incoherent parcels, after long intervals of neglect resumed again as humour and occasions permitted," and published after almost twenty years as An Essay Concerning Human Understanding.
Locke's fortunes were closely linked with those of Shaftesbury, and when the Earl fell from power in 1675, Locke withdrew from public life. He went to France, where he remained four years, during which he sought to restore his health, which had never been good, and to work upon his Essay. At Montpellier he was the neighbor of the Earl of Pembroke, later also the patron of Berkeley, to whom he dedicated his work. When Shaftesbury again arose to power in 16 79, Locke returned to England and resumed his former activities. Although he seems to have played little part in Shaftesbury's plotting with Monmouth against the King which led to the Earl's exile and death, he fell under royal suspicion, and in 1683 he found it safer to seek refuge in Holland. Fearing arrest at the insistence of the English Government, he lived at first in Amsterdam under the assumed name of Dr. Van der Linden. He rapidly formed congenial associations, especially among the Remonstrants, with whom Spinoza had also lived, and settled down to complete the Essay. In 1687 he made his first appearance as an author by publishing an abstract of it in the Bibliothèque Universelle of his friend, Le Clerc. It seems likely that he was involved to some extent in planning the Revolution of 1688. He had friends among the English refugees, he was known to William of Orange, and he returned to England in 1689 in the same ship which carried William's wife, Princess Mary.
Although Locke was offered several responsible positions in the new regime, he preferred to devote himself to his writings and accepted only the comparatively light task of commissioner of appeals. Within four years he completed his most important works. The Letter Concerning Toleration, which had been written and published in Latin in Holland, appeared in English the year of his return. In 1690 the Two Treatises on Civil Government and the Essay appeared, and three years later the Thoughts on Education.
Prompted by ill-health and dissatisfaction with the course of public affairs, Locke retired in 1691 to Oates Manor in Essex, the home of Lady Masham, daughter of Ralph Cudworth, the Cambridge Platonist. He continued to work at the Essay and in 1694 published a second edition; a third and fourth edition were also brought out during his life time. The Essay and Letter Concerning Toleration involved him in a long series of controversies regarding the religious implications of his teaching. The Second and Third Letter Concerning Toleration, the pamphlets interchanged with Bishop Stillingfleet of Worcester, and the Reasonableness of Christianity belong to these years, as does the series of letters to Isaac Newton. He continued to be occupied with political problems and expressed his views on currency reform in his Observations on Silver Money and Further Considerations on Raising the Value of Money. Upon the establishment of a commission on trade and plantations, Locke reluctantly accepted a post as one of the commissioners. This office absorbed all the time his health permitted him to spend in London from 1696 to 1700, when constant illness compelled his resignation.
Locke's last years were spent quietly in retirement at Oates. He occupied himself with biblical studies and wrote a commentary on St. Paul's Epistles. He was in the midst of writing a Fourth Letter on Toleration when he died on October 28, 1704. He was buried near Oates by the parish church of High Laver.