John Locke, an English philosopher, born at Wrington, Somersetshire, Aug. 29, 1632, died at Oates, a country seat in Essex, Oct. 28, 1704. The moderate inheritance of his family was considerably reduced during the civil wars, in which his father was a parliamentary captain. Under the brief political ascendancy of the Puritans he imbibed the religious principle and spirit of liberty which actuated that body of men. His education began at Westminster school, from which he was elected in 1651 to Christchurch college, Oxford, where he graduated bachelor of arts in 1655 and master in 1658, continuing to reside in that city till 1664. In after life he regretted that he had spent so much of his time in the university, chiefly from his contempt of the scholastic philosophy and methods which were there upheld; yet he applied himself diligently to the classics, read in private the works of Bacon and Descartes, and enjoyed the friendship of persons whose society and conversation first suggested the idea of his greatest work. His companions were chosen rather from among the lively and agreeable than the studious and learned, and his early correspondence often displays wit and irony.

The precise and scientific method of Descartes seems to have given the first impulse to his speculations, but Bacon exerted a more permanent and congenial influence, and he may be called the metaphysician of the Baconian philosophy. After receiving his degrees he devoted himself principally to medicine, which occupied much of his attention through life, and his eminent proficiency in which is attested by Dr. Sydenham, the greatest authority of his time. In 1664 he accepted the post of secretary in a diplomatic mission to the court of Brandenburg, and, returning to Oxford within a year, was in doubt whether to begin the practice of medicine as a profession, to continue in diplomatic employment, offers of which both in Spain and Germany were made to him, or to enter the church, a considerable preferment in which was promised through the duke of Or-mond, lord lieutenant of Ireland. He was engaged in studies in experimental philosophy, when in 1666 he became acquainted with Lord Ashley, afterward earl of Shaftesbury, who was then suffering from an abscess in the chest.

Locke divined the nature of the disorder, which no one else had been able to discover; the life of the nobleman was believed to have been saved by a surgical operation which the philosopher advised; and the result was a close and permanent friendship between them. Locke accompanied him to London, and in his house enjoyed the society of the duke of Buckingham, the earl of Northumberland, Lord Halifax, and others of the most distinguished characters of the time. Ashley united engaging manners with distinguished ability, and was an admirable talker; and Locke, whose esteem for conversational capacity led him to assign it a first place in the formation of a man's mind, was probably attached in this instance very much by this quality. While residing with him he superintended the education of his son, and subsequently of his grandson the third earl of Shaftesbury, the elegant philosophical writer of Queen Anne's reign. In 1668 he accompanied the earl and countess of Northumberland on a tour in France, and after his return was employed by Ashley to draw up the fundamental laws of Carolina, which province had been granted to him and seven others.

The scheme of government which was prepared, aristocratic and conformed to monarchy, yet tolerant of all religions, indicates the cautious and practical tendencies of his mind, since, though a lover of freedom, he proposed to establish it in a new country only in so far as it had been realized in England. In 1670 he made the first sketch of his "Essay concerning Human Understanding," which was finished in 1687 and published in 1690. In a discussion with five or six friends at his chambers in Oxford, he suggested that the dispute and perplexity could only be solved by a preliminary examination of our own abilities, and of what subjects our understandings are or are not fitted to deal with. He set down several thoughts on the subject previous to their next meeting, and the work thus begun was often resumed and often neglected during his various avocations, and was ultimately completed in retirement and leisure. While Shaftesbury was lord chancellor, Locke held the appointment of secretary for the presentation of benefices, and afterward of secretary to the board of trade.

In 1675 he went to France for the benefit of his health, residing in Mont-pellier, where he became acquainted with Mr. Herbert, afterward earl of Pembroke, to whom his "Essay " is dedicated, and in Paris, where his conversation was welcomed by the most eminent literary and scientific men. He was recalled to England when Shaftesbury regained power for a brief season in 1679; and when that nobleman, charged with high treason, had taken refuge in Holland, he followed him thither in 1683. He continued to reside there after the death of Shaftesbury, having incurred the hostility of the court by his connection with him. At Amsterdam he kept aloof from the British exiles who were plotting the rebellion of Monmouth, auguring their ill success, and joined with Limborch, Le Clerc, and others, in the formation of a philosophical society for the weekly discussion of important questions. Spies were set about him to suggest irritating topics, and to report his words to his ruin, but they were foiled by his steady silence concerning the politics of the day. The court therefore resolved to punish him in the only point where he was vulnerable, and ejected him from his studentship in Christchurch college.

Still he refused to take part in the schemes of invasion, and concealed himself at Utrecht, where he was employed in writing his letter " On Toleration." In the Biblio-theque universelle et historique of Le Clerc he published in French in 1686 a "New Method of a Commonplace Book," in 1687 an abridgment of his "Essay on the Human Understanding," and in 1688 his letter "On Toleration," which was published in England in the same year, and in Latin at Gouda in 1689. Its liberal views were attacked by an Oxford theologian, and were defended by Locke in two additional letters. Adopting the theory of a compact, he maintained that the state relates only to civil interests, has nothing to do with matters in the world to come, and should therefore tolerate all modes of worship not immoral in their nature or involving doctrines inimical to good government. Conscious of no crime, he refused to accept a pardon which William Penn promised to obtain for him from James II., but returned to England after the revolution of 1688 in the same fleet which brought the princess of Orange, and obtained through Lord Mordaunt the office of commissioner of appeals.

In 1690 appeared his " Essay concerning Human Understanding," the first work which attracted attention in England to metaphysical speculations, except on the part of merely studious men, and one of the greatest contributions in modern times to the philosophy of the human mind. The celebrity of the author as a friend of civil and religious liberty, the attacks upon it, and the attempts made at Oxford to prevent the students from reading it, were among the secondary causes of its success. Six editions appeared within 14 years, and through translations into Latin and French the fame of the author was made European. He published in 1690 two " Treatises on Civil Government," written to support the principles of the revolution by establishing the title of King William upon the consent of the people as the only title of lawful government; in 1693 his "Thoughts concerning Education," in which his object is to fashion a gentleman rather than a scholar, and therefore he lays less stress on learning than on virtue, breeding, and practical wisdom; and in 1695 "The Reasonableness of Christianity," the object of which was to determine what points of belief were common to all the Christian sects, in order to facilitate a plan of the king for the reconciliation and union of them all.

He published a vindication of this work against the charge of Socinianism, and conducted a controversy with Stillingfleet, who in his work on the Trinity denounced some of the principles of the "Essay"as opposed to fundamental Christian doctrines. In 1700 he resigned his commissionership in consequence of his failing health, and, declining a pension offered him by the king in a personal interview, retired to the mansion of his friend Sir Francis Masham at Oates, in Essex, where he devoted the remainder of his life to the study of the Scriptures. Among the fruits of his later labors were a " Discourse on the Miracles," " Paraphrases, with Notes, of the Epistles of St. Paul," and an "Examination of Father Malebranche's Opinion of Seeing all Things in God," which were published posthumously. His excellent treatise on the " Conduct of the Understanding," which maybe regarded as the ethical application of his "Essay," being a scheme of the education which an adult person should givehimself, also appeared after his death.

He received during his last years, while suffering under an incurable asthma, the affectionate attentions of Lady Masham, a daughter of Ralph Cudworth, and died ultimately in his chair, from the natural decay of a constitution originally weak, while she was reading the Psalms to him. - The course and circumstances of Locke's life were in every respect favorable to the production of such a work as the " Essay concerning Human Understanding." Early imbued with a zeal for liberty and with the principles of a severe morality, his whole life was a warfare against the enemies of freedom in speculation, freedom in worship, and freedom from every unnecessary political restraint. Acquainted by his studies both with scholastic subtleties and the physical sciences, he was in mature age admitted to the society of wits and politicians, and became a man of business and of the world. The " Essay " was the product of meditation continued through many years, was composed at intervals, and is in a studied colloquial and rather racy style, which, however attractive to the reader, is too figurative, ambiguous, various, and even contradictory, for the purposes of philosophy.

The essential character and tendency of his system has therefore always been a matter of dispute between metaphysicians of different schools, and different passages suggest very opposite conclusions. His object was to inquire into the origin, certainty, and extent of human knowledge, and his method was purely psychological, by the patient and tentative observation of the phenomena of consciousness. In the first book he confutes the Cartesian doctrine of innate principles or axioms, which would conflict with his whole theory of the empirical origin of our ideas. This theory is fully developed in the second book, in which he shows that our natural faculties are capable of forming every notion that we possess, that the action of these faculties takes its rise from experience, and that the mind may therefore be compared to a sheet of white paper void of all characters till the events of time inscribe them. Having thus stated the principle that all the materials of our knowledge come from experience, he explains it more particularly by making a distinction between sensation and reflection as sources of ideas. The former is observation of the external world, the latter of our own mental operations.

Though he uses the term reflection in a wavering and indefinite sense, it does not plainly appear that he ascribed to it any other power than that of a mere formal and logical mechanism, to act upon, to combine and compare, and to extensively modify the materials primarily afforded by the senses. In long and acute processes of reasoning he aims to bring the ideas of space, time, infinity, causality, personal identity, substance, and good and evil within the limits of experience. The third book is a treatise on the nature, use, and abuse of language. In the fourth book he passes from ideas to knowledge, from psychology to ontology, treating the question as to the adequacy of our ideas and the reality of our knowledge. He held a representative theory of perception, maintaining that the mind does not know things immediately, but by the intervention of ideas; that knowledge is real only in so far as there is conformity between our ideas and the reality of things; and that ideas may be entirely inadequate, however distinct they are, thus rejecting the criterion of Descartes. This theory contains the germ of utter skepticism, and was the ground on which Berkeley denied the existence of the material world, and Hume involved all human knowledge in doubt.

The distinction established by Kant between the cause and the occasion.of our conceptions, making the former to exist in the original constitution of the mind, and the latter in the circumstances of experience, would have removed the fundamental error involved, perhaps without design, in the system of Locke. There are indications in many passages of his work that he was not satisfied with that tendency to sensationalism, which when rigidly developed bore fruits of utilitarianism in morals, materialism in metaphysics, and skepticism in religion. - A biography of Locke was published in 1829 by Lord King, a lineal descendant of his sister, and added to Bonn's "Standard Library1' in 1858. The best complete edition of his works is in 10 vols. (London, 1823). His philosophical works have been published by J. A. St. John (2d ed., 2 vols., London, 1854). A new biography by H. R. Fox Bourne was announced in 1874.