John Locke (1632-1704), English philosopher, was born at Wrington, 16 km W. of Belluton, in Somerset, on the 29th of August 1632, six years after the death of Bacon, and three months before the birth of Spinoza. His father was a small landowner and attorney at Pensford, near the northern boundary of the county, to which neighborhood the family had migrated from Dorset early in that century. The elder Locke, a strict but genial Puritan, by whom the son was carefully educated at home, was engaged in the military service of the parliamentary party. "From the time that I knew anything", Locke wrote in 1660, "I found myself in a storm, which has continued to this time". For fourteen years his education, more or less interrupted, went on in the rural home at Belluton, on his father's little estate, a kilometer from Pensford, and 10 km from Bristol. In 1646 he entered Westminster School and remained there for six years. Westminster was uncongenial to him. Its memories perhaps encouraged the bias against public schools which afterwards disturbed his philosophic calm in his Thoughts on Education. In 1652 he entered Christ Church, Oxford, then under John Owen, the Puritan dean and vice-chancellor of the university. Christ Church was Locke's occasional home for thirty years. For some years after he entered, Oxford was ruled by the Independents, who, largely through Owen, unlike the Presbyterians, were among the first in England to advocate genuine religious toleration. But Locke's hereditary sympathy with the Puritans was gradually lessened by the intolerance of the Presbyterians and the fanaticism of the Independents. He had found in his youth, he says, that "what was called general freedom was general bondage, and that the popular assertors of liberty were the greatest engrossers of it too, and not unfitly called its keepers". And the influence of the liberal divines of the Church of England afterwards showed itself in his spiritual development.
Under Owen scholastic studies were maintained with a formality and dogmatism unsuited to Locke's free inquisitive temper. The aversion to them which he expressed showed thus early an innate disposition to rebel against empty verbal reasoning. He was not, according to his own account of himself to Lady Masham, a hard student at first. He sought the company of pleasant and witty men, and thus gained knowledge of life. He took the ordinary bachelor's degree in 1656, and the master's in 1658. In December 1660 he was serving as tutor of Christ Church, lecturing in Greek, rhetoric and philosophy.
At Oxford Locke was nevertheless within reach of liberal intellectual influence tending to promote self-education and strong individuality. The metaphysical works of Descartes had appeared a few years before he went to Oxford, and the Human Nature and Leviathan of Hobbes during his undergraduate years. It does not seem that Locke read extensively, but he was attracted by Descartes. The first books, he told Lady Masham, which gave him a relish for philosophy, were those of this philosopher, although he very often differed from him. At the Restoration potent influences were drawing Oxford and England into experimental inquiries. Experiment in physics became the fashion. The Royal Society was then founded, and we find Locke experimenting in chemistry in 1663, also in meteorology, in which he was particularly interested all his life.
The restraints of a professional career were not suited to Locke. There is a surmise that early in his Oxford career he contemplated taking orders in the Church of England. His religious disposition attracted him to theology. Revulsion from the dogmatic temper of the Presbyterians, and the unreasoning enthusiasm of the Independents favored sympathy afterwards with Cambridge Platonists and other liberal Anglican churchmen. Whichcote was his favorite preacher, and close intimacy with the Cudworth family cheered his later years. But, though he has a place among lay theologians, dread of ecclesiastical impediment to free inquiry, added to strong inclination for scientific investigation, made him look to medicine as his profession, and before 1666 we find him practicing as a physician in Oxford. Nevertheless, although known among his friends as "Doctor Locke", he never graduated in medicine. His health was uncertain, for he suffered through life from chronic consumption and asthma. A fortunate event soon withdrew him from the medical profession.
Locke early showed an inclination to politics, as well as to theology and medicine. As early as 1665 he diverged for a short time from medical pursuits at Oxford, and was engaged as secretary to Sir Walter Vane on his mission to the Elector of Brandenburg. Soon after his return in 1666 the incident occurred which determined his career. Lord Ashley, afterwards first earl of Shaftesbury, had come to Oxford for his health. Locke was introduced to him by his physician, Dr. Thomas. This was the beginning of a lasting friendship, sustained by common sympathy with liberty—civil, religious and philosophical. In 1667 Locke moved from Christ Church to Exeter House, Lord Ashley's London residence, to become his confidential secretary. Although he retained his studentship at Christ Church, and occasionally visited Oxford, as well as his patrimony at Belluton, he found a home and shared fortune with Shaftesbury for fifteen years.
Locke's commonplace books throw welcome light on the history of his mind in early life. A paper on the "Roman Commonwealth" which belongs to this period, expresses convictions about religious liberty and the relations of religion to the state that were modified and deepened afterwards; objections to the sacerdotal conception of Christianity appear in another article; short work is made of ecclesiastical claims to infallibility in the interpretation of Scripture in a third; a scheme of utilitarian ethics, wider than that of Hobbes, is suggested in a fourth. The most significant of those early revelations is the Essay concerning Toleration (1666), which anticipates conclusions more fully argued nearly thirty years later.
The Shaftesbury connection must have helped to save Locke from those idols of the "Den" to which professional life and narrow experience is exposed. It brought him into contact with public men, the springs of political action and the duties of high office. The place he held as Shaftesbury's adviser is indeed the outstanding circumstance in his middle life. Exeter House afforded every opportunity for society. He became intimate among others with the illustrious Sydenham; he joined the Royal Society and served on its council. The foundation of the monumental work of his life was laid when he was at Exeter House. He was led to it in this way. It was his habit to encourage informal reunions of his intimates, to discuss debatable questions in science and theology. One of these, in the winter of 1670, is historically memorable. "Five or six friends", he says, met in his rooms and were discussing "principles of morality and religion. They found themselves quickly at a stand by the difficulties that arose on every side". Locke proposed some criticism of the necessary "limits of human understanding" as likely to open a way out of their difficulties. He undertook to attempt this, and fancied that what he had to say might find sufficient space on "one sheet of paper". What was thus "begun by chance, was continued by entreaty, written by incoherent parcels, and after long intervals of neglect resumed again as humor and occasions permitted". At the end of nearly twenty years the issue was given to the world as Locke's now famous Essay Concerning Human Understanding.
The fall of Shaftesbury in 1675 enabled Locke to escape from English politics. He found a retreat in France, where he could unite calm reflection upon the legitimate operations of "human understanding" with attention to his health. He spent three years partly at Montpellier and partly in Paris. His journals and commonplace books in these years show the Essay in preparation. At Paris he met men of science and letters—Peter Guenellon, the well-known Amsterdam physician; Ole Römer, the Danish astronomer; Thoynard, the critic; Melchisédech Thévenot, the traveller; Henri Justel, the jurist; and François Bernier, the expositor of Gassendi. But there is no mention of Malebranche, whose Recherche de la vérité had appeared three years before, nor of Arnauld, the illustrious rival of Malebranche.
Locke returned to London in 1679. Reaction against the court party had restored Shaftesbury to power. Locke resumed his old confidential relations, now at Thanet House in Aldersgate. A period of often interrupted leisure for study followed. It was a time of plots and counterplots, when England seemed on the brink of another civil war. In the end Shaftesbury was committed to the Tower, tried and acquitted. More insurrectionary plots followed in the summer of 1682, after which, suspected at home, the versatile statesman escaped to Holland, and died at Amsterdam in January 1683. In these two years Locke was much at Oxford and in Somerset, for the later movements of Shaftesbury did not commend themselves to him. Yet the government had their eyes upon him. "John Locke lives a very cunning unintelligible life here", Prideaux reported from Oxford in 1682. "I may confidently affirm", wrote John Fell, the dean of Christ Church, to Lord Sunderland, "there is not any one in the college who has heard him speak a word against, or so much as censuring, the government; and, although very frequently, both in public and private, discourses have been purposely introduced to the disparagement of his master, the earl of Shaftesbury, he could never be provoked to take any notice, or discover in word or look the least concern; so that I believe there is not in the world such a master of taciturnity and passion". Unpublished correspondence with his Somerset friend, Edward Clarke of Chipley, describes Locke's life in those troubled years. It also reveals the opening of his intimate intercourse with the Cudworth family, who were friends of the Clarkes, and connected by birth with Somerset. The letters allude to toleration in the state and comprehension in the church, while they show an indifference to theological dogma hardly consistent with an exclusive connection with any sect.
In his fifty-second year, in the gloomy autumn of 1683, Locke retired to Holland, then the asylum of eminent persons who were elsewhere denied liberty of thought. Descartes and Spinoza had speculated there; it had been the home of Erasmus and Grotius; it was now the refuge of Bayle. Locke spent more than five years there; but his (unpublished) letters show that exile sat heavily upon him. Amsterdam was his first Dutch home, where he lived in the house of Dr. Keen, under the assumed name of Dr. Van der Linden. For a time he was in danger of arrest at the instance of the English government. After months of concealment he escaped; but he was deprived of his studentship at Christ Church by order of the king, and Oxford was thus closed against him. Holland introduced him to new friends. The chief of these was Limborch, the successor of Episcopius as Remonstrant professor of theology, lucid, learned and tolerant, the friend of Cudworth, Whichcote and More. By Limborch he was introduced to Le Clerc, the youthful representative of letters and philosophy in Limborch's college, who had escaped from Geneva and Calvinism to the milder atmosphere of Holland and the Remonstrants. The Bibliothèque universelle of Le Clerc was then the chief organ in Europe of men of letters. Locke contributed several articles. It was his first appearance as an author, although he was now fifty-four years of age. This tardiness in authorship is a significant fact in his life, in harmony with his tempered wisdom.
In the next fourteen years the world received through his books the thoughts which had been gradually forming, and were taking final shape while he was in Holland. The Essay was finished there, and a French epitome appeared in 1688 in Le Clerc's journal, the forecast of the larger work. Locke was then at Rotterdam, where he lived for a year in the house of a Quaker friend, Benjamin Furley, or Furly, a wealthy merchant and lover of books. At Rotterdam he was a confidant of political exiles, including Burnet and the famous earl of Peterborough, and he became known to William, prince of Orange. William landed in England in November 1688; Locke followed in February 1689, in the ship which carried the princess Mary.
After his return to England in 1689 Locke emerged through authorship into European fame. Within a month after he reached London he had declined an offer of the embassy to Brandenburg, and accepted the modest office of commissioner of appeals. The two following years, during which he lived at Dorset Court in London, were memorable for the publication of his two chief works on social polity, and of the epoch-making book on modern philosophy which reveals the main principles of his life. The earliest of these to appear was his defense of religious liberty, in the Epistola de Tolerantia, addressed to Limborch, published at Gouda in the spring of 1689, and translated into English in autumn by William Popple, a Unitarian merchant in London. Two Treatises of Government, in defense of the right of ultimate sovereignty in the people, followed a few months later. The famous Essay concerning Human Understanding saw the light in the spring of 1690. He received £30 for the copyright, nearly the same as Kant got in 1781 for his Kritik der reinen Vernunft. In the Essay Locke was the critic of the empirical data of human experience: Kant, as the critic of the intellectual and moral presuppositions of experience, supplied the complement to the incomplete and ambiguous answer to its own leading question that was given in Locke's Essay. The Essay was the first book in which its author's name appeared, for the Epistola de Tolerantia and the Treatises on Government were anonymous.
Locke's asthma was aggravated by the air of London; and the course of public affairs disappointed him, for the settlement at the Revolution fell short of his ideal. In spring, 1691, he took up his residence in the manor house of Otes in Essex, the country seat of Sir Francis Masham, between Ongar and Harlow. Lady Masham was the accomplished daughter of Ralph Cudworth, and was his friend before he went to Holland. She told Le Clerc that after Locke's return from exile, "by some considerably long visits, he had made trial of the air of Otes, which is some 20 miles from London, and he thought that none would be so suitable for him. His company", she adds, "could not but be very desirable for us, and he had all the assurances we could give him of being always welcome; but, to make him easy in living with us, it was necessary he should do so on his own terms, which Sir Francis at last assenting to, he then believed himself at home with us, and resolved, if it pleased God, here to end his days as he did". At Otes he enjoyed for fourteen years as much domestic peace and literary leisure as was consistent with broken health, and sometimes anxious visits to London on public affairs, in which he was still an active adviser. Otes was in every way his home. In his letters and otherwise we have pleasant pictures of its inmates and domestic life and the occasional visits of his friends, among others Lord Peterborough, Lord Shaftesbury of the Characteristics, Sir Isaac Newton, William Molyneux and Anthony Collins.
At Otes he was busy with his pen. The Letter on Toleration involved him in controversy. An Answer by Jonas Proast of Queen's College, Oxford, had drawn forth in 1690 a Second Letter. A rejoinder in 1691 was followed by Locke's elaborate Third Letter on Toleration in the summer of the following year. In 1691 currency and finance were much in his thoughts, and in the following year he addressed an important letter to Sir John Somers on the Consequences of the Lowering of Interest and Raising the Value of Money. When he was in Holland he had written letters to his friend Clarke of Chipley about the education of his children. These letters formed the substance of the little volume entitled Thoughts on Education (1693), which still holds its place among classics in that department. Nor were the "principles of revealed religion" forgotten. The subtle theological controversies of the 17th century made him anxious to show how simple after all fundamental Christianity is. In the Reasonableness of Christianity as delivered in the Scriptures (anonymous, 1695), Locke sought to separate the divine essence of Christ's religion from later accretions of dogma, and from reasonings due to oversight of the necessary limits of human thought. This intended Eirenicon involved him in controversies that lasted for years. Angry polemics assailed the book. A certain John Edwards was conspicuous. Locke's Vindication, followed by a Second Vindication in 1697, added fuel to this fire. Above all, the great Essay was assailed and often misinterpreted by philosophers and divines. Notes of opposition had been heard almost as soon as it appeared. John Norris, the metaphysical rector of Bemerton and English disciple of Malebranche, criticized it in 1690. Locke took no notice at the time, but his second winter at Otes was partly employed in An Examination of Malebranche's Opinion of Seeing all Things in God, and in Remarks upon some of Mr. Norris's Books, tracts which throw light upon his own ambiguous theory of perception through the senses. These were published after his death. A second edition of the Essay, with a chapter added on "Personal Identity", and numerous alterations in the chapter on "Power", appeared in 1694. The third, which was only a reprint, was published in 1695. Wynne's well-known abridgment helped to make the book known in Oxford, and his friend William Molyneux introduced it in Dublin. In 1695 a revival of controversy about the currency diverted Locke's attention. Events in that year occasioned his Observations on Silver Money and Further Considerations on Raising the Value of Money.
In 1696 Locke was induced to accept a commissionership on the Board of Trade. This required frequent visits to London. Meantime the Essay on Human Understanding and the Reasonableness of Christianity were becoming more involved in a wordy warfare between dogmatists and latitudinarians, trinitarians and unitarians. The controversy with Edwards was followed by a more memorable one with Stillingfleet, bishop of Worcester. John Toland, in his Christianity not Mysterious, had exaggerated doctrines in the Essay, and then adopted them as his own. In the autumn of 1696, Stillingfleet, an argumentative ecclesiastic more than a religious philosopher, in his Vindication of the Doctrine of the Trinity, charged Locke with disallowing mystery in human knowledge, especially in his account of the metaphysical idea of "substance". Locke replied in January 1697. Stillingfleet's rejoinder appeared in May, followed by a Second Letter from Locke in August, to which the bishop replied in the following year. Locke's Third Letter, in which the ramifications of this controversy are pursued with a copious expenditure of acute reasoning and polished irony, was delayed till 1699, in which year Stillingfleet died. Other critics of the Essay entered the lists. One of the ablest was John Sergeant, a priest of the Roman Church, in Solid Philosophy Asserted Against the Fancies of the Ideists (1697). He was followed by Thomas Burnet and Dean Sherlock. Henry Lee, rector of Titchmarsh, criticized the Essay, chapter by chapter in a folio volume entitled Anti-Scepticism (1702); John Broughton dealt another blow in his Psychologia (1703); and John Norris returned to the attack, in his Theory of the Ideal or Intelligible World (1701-1704). On the other hand Locke was defended with vigor by Samuel Bolde, a Dorset clergyman. The Essay itself was meanwhile spreading over Europe, impelled by the name of its author as the chief philosophical defender of civil and religious liberty. The fourth edition (the last while Locke was alive) appeared in 1700, with important additional chapters on "Association of Ideas" and "Enthusiasm". What was originally meant to form another chapter was withheld. It appeared among Locke's posthumous writings as The Conduct of the Understanding, one of the most characteristic of his works. The French translation of the Essay by Pierre Coste, Locke's amanuensis at Otes, was issued almost simultaneously with the fourth edition. The Latin version by Richard Burridge of Dublin followed a year after, reprinted in due time at Amsterdam and at Leipzig.
In 1700 Locke resigned his commission at the Board of Trade, and devoted himself to Biblical studies and religious meditation. The Gospels had been carefully studied when he was preparing his Reasonableness of Christianity. He now turned to the Epistles of St. Paul, and applied the spirit of the Essay and the ordinary rules of critical interpretation to a literature which he venerated as infallible, like the pious Puritans who surrounded his youth. The work was ready when he died, and was published two years after. A tract on Miracles, written in 1702, also appeared posthumously. Fresh adverse criticism of the Essay was reported to him in his last year, and the book was formally condemned by the authorities at Oxford. "I take what has been done rather as a recommendation of the book", he wrote to his young friend Anthony Collins, "and when you and I next meet we shall be merry on the subject". One attack only moved him. In 1704 his adversary, Jonas Proast, revived their old controversy. Locke in consequence began a Fourth Letter on Toleration. A few pages, ending in an unfinished paragraph, exhausted his remaining strength; but the theme which had employed him at Oxford more than forty years before, and had been a ruling idea throughout the long interval, was still dominant in the last days of his life.
All the summer of 1704 he continued to decline, tenderly nursed by Lady Masham and her step-daughter Esther. On the 28th of October he died, according to his last recorded words, "in perfect charity with all men, and in sincere communion with the whole church of Christ, by whatever names Christ's followers call themselves". His grave is on the south side of the parish church of High Laver, in which he often worshipped, near the tombs of the Mashams, and of Damaris, the widow of Cudworth. At the distance of 1.5 km are the garden and park where the manor house of Otes once stood.
Locke's writings have made his intellectual and moral features familiar. The reasonableness of taking probability as our guide in life was in the essence of his philosophy. The desire to see for himself what is true in the light of reasonable evidence, and that others should do the same, was his ruling passion, if the term can be applied to one so calm and judicial. "I can no more know anything by another man's understanding", he would say, "than I can see by another man's eyes". This repugnance to believe blindly what rested on arbitrary authority, as distinguished from what was seen to be sustained by self-evident reason, or by demonstration, or by good probable evidence, runs through his life. He is typically English in his reverence for facts, whether facts of sense or of living consciousness, in his aversion from abstract speculation and verbal reasoning, in his suspicion of mysticism, in his calm reasonableness, and in his ready submission to truth, even when truth was incapable of being fully reduced to system by man. The delight he took in exercising reason in regard to everything he did was what his friend Pierre Coste remarked in Locke's daily life at Otes. "He went about the most trifling thing he did and always with some good reason. ... Above all things he loved order; and he had got the way of observing it in everything with wonderful exactness. As he always kept the useful in his eye in all his disquisitions, he esteemed the employments of men only in proportion to the good they were capable of producing; for which reason he had no great value for the critics who waste their lives in composing words and phrases in coming to the choice of a various reading, in a passage that has after all nothing important in it. He cared yet less for those professed disputants, who, being taken up with the desire of coming off with victory, justify themselves behind the ambiguity of a word, to give their adversaries the more trouble. And whenever he had to deal with this sort of folks, if he did not beforehand take a strong resolution of keeping his temper, he quickly fell into a passion; for he was naturally somewhat choleric, but his anger never lasted long. If he retained any resentment it was against himself, for having given way to so ridiculous a passion; which, as he used to say, may do a great deal of harm, but never yet did anyone the least good". Large, "round-about" common sense, intellectual strength directed by a virtuous purpose, not subtle or daring speculation sustained by an idealizing faculty, in which he was deficient, is what we find in Locke. Defect in speculative imagination appears when he encounters the vast and complex final problem of the universe in its organic unity.
Locke is apt to be forgotten now, because in his own generation he so well discharged the intellectual mission of initiating criticism of human knowledge, and of diffusing the spirit of free inquiry and universal toleration which has since profoundly affected the civilized world. He has not bequeathed an imposing system, hardly even a striking discovery in metaphysics, but he is a signal example in the Anglo-Saxon world of the love of attainable truth for the sake of truth and goodness. "If Locke made few discoveries, Socrates made none". But both are memorable in the record of human progress.
In the inscription on his tomb, prepared by himself, Locke refers to his books as a true representation of what he was. They are concerned with Social Economy, Christianity, Education and Philosophy, besides Miscellaneous writings.
I. Social Economy.—(1) Epistola de Tolerantia (1689, translated into English in the same year). (2) Two Treatises of Government (1690) (the Patriarcha of Filmer, to which the First Treatise was a reply, appeared in 1680). (3) A Second Letter concerning Toleration (1690). (4) Some Considerations on the Consequence of Lowering the Rate of Interest and Raising the Value of Money (1691). (5) A Third Letter for Toleration (1692). (6) Short Observations on a printed paper entitled, "For encouraging the Coining of Silver Money in England, and after for Keeping it here" (1695). (7) Further Considerations concerning Raising the Value of Money (1695) (occasioned by a Report containing an "Essay for the Amendment of Silver Coins", published that year by William Lowndes, secretary for the Treasury). (8) A Fourth Letter for Toleration (1706, posthumous).
II. Christianity.—(1) The Reasonableness of Christianity as delivered in the Scriptures (1695). (2) A Vindication of the Reasonableness of Christianity from Mr. Edwards's Reflections (1695). (3) A Second Vindication of the Reasonableness of Christianity (1697). (4) A Paraphrase and Notes on the Epistles of St. Paul to the Galatians, First and Second Corinthians, Romans and Ephesians. To which is prefixed an Essay for the understanding of St. Paul's Epistles by consulting St. Paul himself (1705-1707, posthumous). (5) A Discourse of Miracles (1716, posthumous).
III. Education.—(1) Some Thoughts concerning Education (1693). (2) The Conduct of the Understanding (1706, posthumous). (3) Some Thoughts concerning Reading and Study for a Gentleman (1706, posthumous). (4) Instructions for the Conduct of a Young Gentleman (1706, posthumous). (5) Of Study (written in France in Locke's journal, and published in Lord King's Life of Locke in 1830).
IV. Philosophy.—(1) An Essay concerning Human Understanding, in four books (1690). (2) A Letter to the Bishop of Worcester concerning some Passages relating to Mr. Locke's Essay of Human Understanding in a late Discourse of his Lordship's in Vindication of the Trinity (1697). (3) Mr. Locke's Reply to the Bishop of Worcester's Answer to his Letter (1697). (4) Mr. Locke's Reply to the Bishop of Worcester's Answer to his Second Letter (1699). (5) An Examination of Father Malebranche's Opinion of Seeing all Things in God (1706, posthumous). (6) Remarks upon some of Mr. Norris's Books, wherein he asserts Father Malebranche's Opinion of Seeing all Things in God (1720, posthumous).
Miscellaneous.—(1) A New Method of a Common Place Book (1686). This was Locke's first article in the Bibliothèque of Le Clerc; his other contributions to it are uncertain, except the Epitome of the Essay, (in 1688). (2) The Fundamental Constitutions of Carolina (prepared in 1673 when Locke was Lord Shaftesbury's secretary at Exeter House, remarkable for recognition of the principle of toleration, published in 1706, in the posthumous collection). (3) Memoirs relating to the Life of Anthony, First Earl of Shaftesbury (1706). (4) Elements of Natural Philosophy (1706). (5) Observations upon the Growth and Culture of Vines and Olives (1706). (6) Rules of a Society which met once a Week, for their improvement in Useful Knowledge, and for the Promotion of Truth and Christian Charity (1706). (7) A Letter from a Person of Quality to his Friend in the Country, published in 1875 (included by Des Maizeaux in his Collection of Several Pieces of Mr. John Locke's, 1720), and soon afterwards burned by the common hangman by orders from the House of Lords, was disavowed by Locke himself. It may have been dictated by Shaftesbury. There are also miscellaneous writings of Locke first published in the biographies of Lord King (1830) and of Mr. Fox Bourne (1876).
Letters from Locke to Thoynard, Limborch, Le Clerc, Guenellon, Molyneux, Collins, Sir Isaac Newton, the first and the third Lord Shaftesbury, Lords Peterborough and Pembroke, Clarke of Chipley and others are preserved, many of them unpublished, most of them in the keeping of the Earl of Lovelace at Horsley Towers, and of Mr. Sandford at Nynehead in Somerset, or in the British Museum. They express the gracious courtesy and playful humor which were natural to him, and his varied interests in human life.
I. Social Economy.—It has been truly said that all Locke's writings, even the Essay on Human Understanding itself, were occasional, and "intended directly to counteract the enemies of reason and freedom in his own age". This appears in his works on social polity, written at a time when the principles of democracy and toleration were struggling with divine right of kings, and when "the popular assertors of public liberty were the greatest engrossers of it too". "The state" with Locke was the deliberate outcome of free contract rather than a natural growth or organism. That the people, in the exercise of their sovereignty, have the right to govern themselves in the way they judge to be for the common good; and that civil government, whatever form it assumes, has no right to interfere with religious beliefs that are not inconsistent with civil society, is at the foundation of his political philosophy. He rested this sovereignty on virtual mutual contract on the part of the people themselves to be so governed. But the terms of the contract might be modified by the sovereign people themselves, from time to time, in accommodation to changing circumstances. He saw that things in this world were in a constant flux, so that no society could remain long in the same state, and that "the grossest absurdities" must be the issue of "following custom when reason has left the custom". He was always disposed to liberal ecclesiastical concessions for the sake of peace, and he recommended harmonious cooperation with the civil magistrate in all matters of worship and government that were not expressly determined by Scripture.
The social contract
The attack on Sir Robert Filmer in Locke's First Treatise was an anachronism. The democratic principle argued for in the Second Treatise, while in advance of the practice of his age, was in parts anticipated by Aquinas and Bodin, as well as by Grotius and Hooker. Its guiding principle is, that civil rulers hold their power not absolutely but conditionally, government being essentially a moral trust, forfeited if the conditions are not fulfilled by the trustees. This presupposes an original and necessary law of nature or reason, as insisted on by Hooker. But it points to the constitution of civil society in the abstract rather than to the actual origin of government as a matter of fact and past history. There is no historical proof that power was formally entrusted to rulers by the conscious and deliberate action of the ruled. Indeed Locke seems to allow that the consent was at first tacit, and by anterior law of nature conditional on the beneficial purpose of the trust being realized. His Treatises of Government were meant to vindicate the Convention parliament and the English revolution, as well as to refute the ideas of absolute monarchy held by Hobbes and Filmer. They are classics in the library of English constitutional law and polity.
Locke's philosophical defense of religious liberty in the four Letters of Toleration is the most far-reaching of his contributions to social polity. He had a more modest estimate of human resources for forming true judgments in religion, and a less pronounced opinion of the immorality of religious error, than either the Catholic or the Puritan. The toleration which he spent his life in arguing for involved a change from the authoritative and absolute to the relative point of view, as regards man's means of knowledge and belief. It was a protest against those who in theology "peremptorily require demonstration and demand certainty where probability only is to be had". The practice of universal toleration amidst increasing religious differences was an application of the conception of human understanding which governs his Essay. Once a paradox it is now commonplace, and the superabundant argument in the Letters on Toleration fatigues the modern reader. The change is due more to Locke himself than to anyone else. Free thought and liberty of conscience had indeed been pleaded for, on various grounds, in the century in which he lived. Chillingworth, Jeremy Taylor, Glanvill and other philosophical thinkers in the Church of England urged toleration in the state, in conjunction with wide comprehension in the church, on the ground of our necessary intellectual limitation and inability to reach demonstration in theological debates. Puritans like Owen and Goodwin, whose idea of ecclesiastical comprehension was dogmatic and narrow, were ready to accept sectarian variety, because it was their duty to allow many religions in the nation, but only one form of theology within their own sect. The existence of separate nationalities, on the other hand, was the justification of national churches according to the latitudinarian churchmen with whom Locke associated: a national church comprehensive in creed, and thus co-extensive with the nation was their ideal. Locke went far to unite in a higher principle elements in the broad Anglican and the Puritan theories, while he recognized the individual liberty of thought which distinguishes the national church of England. A constant sense of the limits of human understanding was at the bottom of his arguments for tolerance. He had no objection to a national establishment of religion, provided that it was comprehensive enough, and was really the nation organized to promote goodness; not to protect the metaphysical subtleties of sectarian theologians. The recall of the national religion to the simplicity of the gospels would, he hoped, make toleration of nonconformists unnecessary, as few would then remain. To the atheist alone Locke refuses full toleration, on the ground that social obligation can have no hold over him, for "the taking away of God dissolves all". He argued, too, against full toleration of the Church of Rome in England, on the ground of its unnational allegiance to a foreign sovereign. The unfitness of persecution as a means of propagating truth is copiously insisted on by Locke. Persecution can only transform a man into a hypocrite; belief is legitimately formed only by discernment of sufficient evidence; apart from evidence, a man has no right to control the understanding; he cannot determine arbitrarily what his neighbors must believe. Thus Locke's pleas for religious toleration resolve at last into his philosophical view of the foundation and limits of human knowledge.
II. The Reasonableness of Christianity.—The principles that governed Locke's social polity largely determined his attitude to Christianity. His "latitudinarianism" was the result of extraordinary reverence for truth, and a perception that knowledge may be sufficient for the purposes of human life while it falls infinitely short of speculative completeness. He never loses sight of essential reasonableness as the only ground on which Christian faith can ultimately rest. But Locke accepted Holy Scripture as infallible with the reverence of a Puritan. "It has God for its author, salvation for its end, and truth without any mixture of error for its matter". Yet he did not, like many Puritans, mean Scripture as interpreted by himself or by his sect. And faith in its infallibility was combined in Locke with deep distrust in "enthusiasm". This predisposed him to regard physical miracles as the solid criterion for distinguishing reasonable religious conviction from "inclinations, fancies and strong assurances". Assent in religion as in everything else he could justify only on the ground of its harmony with reason; professed "illumination without search, and certainty without proof" was to him a sign of absence of the divine spirit in the professor. Confidence that we are right, he would say, is in itself no proof that we are right: when God asks assent to the truth of a proposition in religion, he either shows us its intrinsic rationality by ordinary means, or he offers miraculous proof of the reality of which we need reasonable evidence. But we must know what we mean by miracle. Reasonableness, in short, must always at last be our guide. His own faith in Christianity rested on its moral excellence when it is received in its primitive simplicity, combined with the miracles which accompanied its original promulgation. But "even for those books which have the attestation of miracles to confirm their being from God, the miracles", he says, "are to be judged by the doctrine, and not the doctrine by the miracles". Miracles alone cannot vindicate the divinity of immoral doctrine. Locke's Reasonableness of Christianity was an attempt to recall religion from the crude speculations of theological sects, destructive of peace among Christians, to its original simplicity; but this is apt to conceal its transcendent mystery. Those who practically acknowledge the supremacy of Jesus as Messiah accept all that is essential to the Christianity of Locke. His own Christian belief, sincere and earnest, was more the outcome of the common sense which, largely through him, molded the prudential theology of England in the 18th century, than of the nobler elements present in More, Cudworth and other religious thinkers of the preceding age, or afterwards in Law and Berkeley, Coleridge and Schleiermacher.
III. Education.—Locke has his place among classic writers on the theory and art of Education. His contribution may be taken as either an introduction to or an application of the Essay on Human Understanding. In the Thoughts on Education imaginative sentiment is never allowed to weigh against utility; information is subordinate to the formation of useful character; the part which habit plays in individuals is always kept in view; the dependence of intelligence and character, which it is the purpose of education to improve, upon health of body is steadily inculcated; to make children happy in undergoing education is a favorite precept; accumulating facts without exercising thought, and without accustoming the youthful mind to look for evidence, is always referred to as a cardinal vice. Wisdom more than much learning is what he requires in the teacher. In instruction he gives the first place to "that which may direct us to heaven", and the second to "the study of prudence, or discreet conduct, and management of ourselves in the several occurrences of our lives, which most assists our quiet prosperous passage through this present life". The infinity of real existence, in contrast with the necessary finitude of human understanding and experience, is always in his thoughts. This "disproportionateness" between the human mind and the universe of reality imposes deliberation in the selection of studies, and disregard for those which lie out of the way of a wise man. Knowledge of what other men have thought is perhaps of too little account with Locke. "It is an idle and useless thing to make it one's business to study what have been other men's sentiments in matters where only reason is to be judge". In his Conduct of the Understanding the pupil is invited to occupy the point at which "a full view of all that relates to a question" is to be had, and at which alone a rational discernment of truth is possible. The uneducated mass of mankind, he complains, either "seldom reason at all", or "put passion in the place of reason", or "for want of large, sound, round-about sense" they direct their minds only to one part of the evidence, "converse with one sort of men, read but one sort of books, and will not come in the hearing of but one sort of notions, and so carve out to themselves a little Goshen in the intellectual world, where light shines, and, as they conclude, day blesses them; but the rest of the vast expansion they give up to night and darkness, and avoid coming near it". Hasty judgment, bias, absence of an a priori "indifference" to what the evidence may in the end require us to conclude, undue regard for authority, excessive love for custom and antiquity, indolence and skeptical despair are among the states of mind marked by him as most apt to interfere with the formation of beliefs in harmony with the Universal Reason that is active in the universe.
IV. Philosophy.—The Essay Concerning Human Understanding embodies Locke's philosophy. It was the first attempt on a great scale, and in the Baconian spirit, to estimate critically the certainty and the adequacy of human knowledge, when confronted with God and the universe.
The "Introduction" to the Essay is the keynote to the whole. The ill-fortune of men in their past endeavors to comprehend themselves and their environment is attributed in a great measure to their disposition to extend their inquiries into matters beyond the reach of human understanding. To inquire with critical care into "the original, certainty and extent of human knowledge, together with the grounds and degrees of belief, opinion and assent", is accordingly Locke's design in this Essay. Excluding from his enquiry "the physical consideration of the mind", he sought to make a faithful report, based on an introspective study of consciousness, as to how far a human understanding of the universe can reach. Although his report might show that our knowledge at its highest must be far short of a "universal or perfect comprehension of whatsoever is", it might still be "sufficient" for us, because "suited to our individual state". The "light of reason", the "candle of the Lord", that is set up in us may be found to shine bright enough for all our purposes. If human understanding cannot fully solve the infinite problem of the universe, man may at least see that at no stage of his finite experience is he necessarily the sport of chance, and that he can practically secure his own well-being.
The last book of the Essay, which treats of Knowledge and Probability, is concerned more directly than the three preceding ones with Locke's professed design. It has been suggested that Locke may have begun with this book. It contains few references to the foregoing parts of the Essay, and it might have appeared separately without being much less intelligible than it is. The other books, concerned chiefly with ideas and words, are more abstract, and may have opened gradually on his mind as he studied more closely the subject treated in the fourth book. For Locke saw that the ultimate questions about our knowledge and its extent presuppose questions about ideas. Without ideas knowledge is impossible. "Idea" is thus a leading term in the Essay. It is used in a way peculiar to himself—"the term which, I think, stands best for whatsoever is the object of the understanding when a man thinks" or "whatever it is which the mind can be employed about". But ideas themselves are, he reminds us, "neither true nor false, being nothing but bare appearances", phenomena as we might call them. Truth and falsehood belong only to assertions or denials concerning ideas, that is, to our interpretations of our ideas according to their mutual relations.
That none of our ideas are "innate" is the argument contained in the first book. This means that the human mind, before any ideas are present to it, is a tabula rasa: it needs the quickening of ideas to become intellectually alive. The inward purpose of this famous argument is apt to be overlooked. It has been criticized as if it was a speculative controversy between empiricism and intellectualism. For this Locke himself is partly to blame. It is not easy to determine the antagonist he had in view. Lord Herbert is referred to as a defender of innateness. Locke was perhaps too little read in the literature of philosophy to do full justice to those more subtle thinkers who, from Plato downwards, have recognized the need for categories of the understanding and presuppositions of reason in the constitution of knowledge. "Innate", Lord Shaftesbury says, "is a word Mr. Locke poorly plays on". For the real question is not about the time when ideas entered the mind, but "whether the constitution of man be such that, being adult and grown up, the ideas of order and administration of a God will not infallibly and necessarily spring up in him". This Locke himself sometimes seems to allow. "That there are certain propositions", we find him saying, "which, though the soul from the beginning, or when a man is born, does not know, yet, by assistance from the outward senses, and the help of some previous cultivation, it may afterwards come certainly to know the truth of, is no more than what I have affirmed in my first book" ("Epistle to Reader", in second edition). And much of our knowledge, as he shows in the fourth book, is rational insight, immediate or else demonstrable, and thus intellectually necessary in its constitution.
What Locke really objects to is, that any of our supposed knowledge should claim immunity from free criticism. He argues in the first book against the innateness of our knowledge of God and of morality; yet in the fourth book he finds that the existence of God is demonstrable, being supported by causal necessity, without which there can be no knowledge; and he also maintains that morality is as demonstrable as pure mathematics. The positions are not inconsistent. The demonstrable rational necessity, instead of being innate, or conscious from our birth, may lie latent or subconscious in the individual mind; but for all that, when we gradually become more awake intellectually, such truths are seen to "carry their own evidence along with them". Even in the first book he appeals to the common reason, which he calls "common sense". "He would be thought void of common sense who asked, on the one side, or, on the other, went to give a reason, why 'it is impossible for the same thing to be and not to be.' It carries its own light and evidence with it, and needs no other proof: he that understands the terms assents to it for its own sake, or else nothing else will ever be able to prevail with him to do it" (bk. i. chap. 3, § 4).
The truth is that neither Locke, on the one hand, nor the intellectualists of the 17th century, on the other, expressed their meaning with enough precision; if they had, Locke's argument would probably have taken a form less open to the charge of mere empiricism. Locke believed that in attacking "innate principles" he was pleading for universal reasonableness instead of blind reliance on authority, and was thus, as he says, not "pulling up the foundations of knowledge", but "laying those foundations surer". When men heard that there were propositions that could not be doubted, it was a short and easy way to assume that what are only arbitrary prejudices are "innate" certainties, and therefore must be accepted unconditionally. This "eased the lazy from the pains of search, stopped the inquiry of the doubtful, concerning all that was once styled innate. It was no small advantage to those who affected to be masters and teachers to make this the principle of principles—that principles must not be questioned". The assumption that they were "innate" was enough "to take men off the use of their own reason and judgment, and to put them upon believing and taking upon trust without further examination. ... Nor is it a small power it gives one man over another to have the authority to make a man swallow that for an innate principle which may serve his purpose who teacheth them" (bk. i. chap. 4, § 24).
Genesis of ideas
The second book proposes a hypothesis regarding the genesis of our ideas and closes after an elaborate endeavor to verify it. The hypothesis is, that all human ideas, even the most complex and abstract and sublime, ultimately depend upon "experience". Otherwise, what we take to be ideas are only empty words. Here the important point is what human "experience" involves. Locke says that our "ideas" all come, either from the five senses or from reflective consciousness; and he proposes to show that even those concerned with the Infinite depend at last on one or other of these two sources: our "complex ideas" are all made up of "simple ideas", either from without or from within. The "verification" of this hypothesis, offered in the thirteenth and following chapters of the second book, goes to show in detail that even those ideas which are "most abstruse", howsoever remote they may seem from original data of outward sense, or of inner consciousness, "are only such as the understanding frames to itself by repeating and joining together simple ideas that it had at first, either from perceiving objects of sense, or from reflection upon its own operations".
To prove this, our thoughts of space, time, infinity, power, substance, personal identity, causality, and others which "seem most remote from the supposed original" are examined in a "plain historical method", and shown to depend either on (a) perception of things external, through the five senses, or on (b) reflection upon operations of the mind within. Reflection, "though it be not sense, as having nothing to do with external objects", is yet, he says, "very like it, and might properly enough be called internal sense". But the suggestion that "sense" might designate both the springs of experience is misleading, when we find in the sequel how much Locke tacitly credits "reflection" with. The ambiguity of his language makes opposite interpretations of this cardinal part of the Essay possible; the best we can do is to compare one part with another, and in doubtful cases to give him the benefit of the doubt.
Although the second book is a sort of inventory of our ideas, as distinguished from the certainty and boundaries of our knowledge, Locke even here makes the assumption that the "simple ideas" of the five senses are practically qualities of things which exist without us, and that the mental "operations" discovered by "reflection" are those of a person continuously existing. He thus relieves himself of the difficulty of having at the outset to explain how the immediate data of outward sense and reflection are accepted as "qualities" of things and persons. He takes this as a fact.
Such, according to Locke, are the only simple ideas which can appear even in the sublimest human speculations. But the mind, in becoming gradually stored with its "simple ideas" is able to elaborate them in numberless modes and relations; although it is not in the power of the most exalted wit or enlarged understanding to invent or frame any new simple idea, not taken in in one or the other of these two ways. All that man can imagine about the universe or about God is necessarily confined to them. For proof of this Locke would have any one try to fancy a taste which had never affected his palate, or to frame the idea of a scent he had never felt, or an operation of mind, divine or human, foreign to all human consciousness.
Qualities of matter
The contrast and correlation of these two data of experience is suggested in the chapter on the "qualities of matter" in which we are introduced to a noteworthy vein of speculation (bk. ii. chap. 8). This chapter, on "things and their qualities", looks like an interpolation in an analysis of mere "ideas". Locke here treats simple ideas of the five senses as qualities of outward things. And the sense data are, he finds, partly (a) revelations of external things themselves in their mathematical relations, and partly (b) sensations, boundless in variety, which are somehow awakened in us through contact and collision with things relatively to their mathematical relations. Locke calls the former sort "primary, original or essential qualities of matter", and the others "secondary or derived qualities". The primary, which are quantities rather than qualities, are inseparable from matter, and virtually identical with the ideas we have of them. On the other hand, there is nothing perceived in the mathematical relations of bodies which in the least resembles their secondary qualities. If there were no sentient beings in existence, the secondary qualities would cease to exist, "except perhaps as unknown modes of the primary, or, if not, as something still more obscure". On the other hand, "solidity, extension, figure and motion would", he assumes, "be really in the world as they are, whether there were any sensible being to perceive them or not".
Thus far the outcome of what Locke teaches about matter is, that it is something capable of being expressed in terms of mathematical quantity, and also in terms of our own sensations. A further step was to suggest the ultimate dependence of the secondary qualities of bodies upon "the bulk, figures, number, situation and motions of the solid parts of which the bodies consist", these mathematical or primary qualities "existing as we think of them whether or not they are perceived". This Locke proposes in a hesitating way. For we, "not knowing what particular size, figure and texture of parts they are on which depend, and from which result, those qualities which make our complex idea, for example, of gold, it is impossible we should know what other qualities result from, or are incompatible with, the same constitution of the insensible parts of gold; and so consequently must always coexist with that complex idea we have of it, or else are inconsistent with it".
Some of the most remarkable chapters in the second book concern what may be called "crucial instances" in verification of its fundamental hypothesis of the dependence of human knowledge upon the simple ideas presented in our dual experience (bk. ii. ch. 13-28). They carry us towards the ultimate mysteries which attract meditative minds. The hypothesis, that even our most profound and sublime speculations are all limited to data of the senses and of reflection, is crucially tested by the "modes" and "substances" and "relations" under which, in various degrees of complexity, we somehow find ourselves obliged to conceive those simple phenomena. Such are modes of quantity in space, and time and number, under which Locke reports that we find ourselves mentally impelled towards immensity, eternity and the innumerable—in a word, towards Infinity which seems to transcend quantity; then there is the complex thought of Substance, to which we find ourselves mysteriously impelled, when the simple phenomena of the senses come to be regarded as qualities of "something"; again there is the obscure idea of the identity of persons, notwithstanding their constant changes of state; and there is, above all, the inevitable tendency we somehow have to refund a change into what we call its "Cause", with the associated idea of active power. Locke begins with our complex ideas of Space, Succession or Time, and Number.
Immensity and endlessness and infinity
Space, he says, appears when we use our senses of sight and touch; succession he finds "suggested" by all the changing phenomena of sense, and by "what passes in our minds"; number is "suggested by every object of our senses, and every thought of our minds, by everything that either doth exist or can be imagined". The modifications of which these are susceptible he reports to be "inexhaustible and truly infinite, extension alone affording a boundless field to the mathematicians". But the mystery latent in our ideas of space and time is, that "something in the mind" irresistibly hinders us from allowing the possibility of any limit to either. We find ourselves, when we try, compelled to lose our positive ideas of finite spaces in the negative idea of Immensity or Boundlessness, and our positive ideas of finite times in the negative thought of Endlessness. We have never seen, and we cannot imagine, an object whose extent is boundless. Yet we find when we reflect that something forces us to think that space and time must be unlimited. Thus Locke seems by implication to acknowledge something added by the mind to the original "simple ideas" of extension and succession; though he finds that what is added is not positively conceivable. When we reflect on immensity and eternity, we find them negations of all that is imaginable; and that whether we try infinite addition or infinite subdivision. He accepts this fact; he does not inquire why mind finds itself obliged to add without limit and to divide without limit. He simply reports that immensity and eternity are inevitable negative ideas, and also that every endeavor to realize them in positive images must be an attempt to represent as quantity what is beyond quantity. After all our additions we are as far from the infinite idea as we were at the beginning.
Substance and personality
Locke is too faithful to facts to overlook the ultimate mysteries in human experience. This is further illustrated in his acknowledgment of the inconceivable that is at the root of our idea of Substance. He tries to phenomenalize it, and thus resolve it into simple ideas; but he finds that it cannot be phenomenalized, and yet that we cannot dispense with it. An unsubstantiated succession of phenomena, without a center of unity to which they are referrable as qualities, is unintelligible: we cannot have a language of adjectives without nouns. Locke had some apprehension of this transcendent intellectual obligation. According to his report, "the mind" always obliges us to suppose something beyond positive phenomena to which the phenomena must be attributed; but he was perplexed by this "confused negative" idea. So for him the word substance means "only an uncertain supposition of we know not what". If one were to ask him what the substance is in which this color and that taste or smell inhere, "he would find himself in a difficulty like that of the Indian, who, after saying that the world rested on an elephant, and the elephant on a broad-backed tortoise, could only suppose the tortoise to rest on 'Something, I know not what.'" The attempt to conceive it is like the attempt positively to conceive immensity or eternity: we are involved in an endless, ultimately incomprehensible, regress. We fail when we try either positively to phenomenalize substance or to dispense with the superphenomenal abstraction. Our only positive idea is of an aggregate of phenomena. And it is only thus, he says, that we can approach a positive conception of God, namely by "enlarging indefinitely some of the simple ideas we received from reflection". Why man must remain in this mental predicament, Locke did not inquire. He only reported the fact. He likewise struggled bravely to be faithful to fact in his report of the state in which we find ourselves when we try to conceive continued personal identity. The paradoxes in which he here gets involved illustrate this (bk. ii. ch. 27).
Locke's thoughts about Causality and Active Power are especially noteworthy, for he rests our knowledge of God and of the external universe on those ultimate ideas. The intellectual demand for "the cause" of an event is what we find we cannot help having; yet it is a demand for what in the end the mind cannot fully grasp. Locke is content to trace the idea of "cause and effect", as far as mere natural science goes, to our "constant observation" that "qualities and finite substances begin to exist, and receive their existence from other beings which produce them". We find that this connection is what gives intelligibility to ceaseless and what seemed chaotic changes, converting them into the divinely concatenated system which we call "the universe". Locke seems hardly to realize all that is implied in scientific prevision or expectation of change. Anything, as far as "constant observation" tells us, might a priori have been the natural cause of anything; and no finite number of "observed" sequences, per se, can guarantee universality and necessity. The idea of power, or active causation, on the other hand, "is got", he acknowledges, not through the senses, but "through our consciousness of our own voluntary agency, and therefore through reflection" (bk. ii. ch. 21). In bodies we observe no active agency, only a sustained natural order in the succession of passive sensuous phenomena. The true source of change in the material world must be analogous to what we are conscious of when we exert volition. Locke here unconsciously approaches the spiritual view of active power in the physical universe afterwards taken by Berkeley, forming the constructive principle of his philosophy.
Ideas and words
Locke's book about Ideas leads naturally to his Third Book which is concerned with Words, or the sensible signs of ideas. Here he analyzes "abstract ideas", and instructively illustrates the confusion apt to be produced in them by the inevitable imperfection of words. He unfolds the relations between verbal signs and the several sorts of ideas; words being the means for enabling us to treat ideas as typical, abstract and general. "Some parts of this third book", concerning Words, Locke tells his friend Molyneux, "though the thoughts were easy and clear enough, yet cost me more pains to express than all the rest of my Essay. And therefore I should not much wonder, if there be in some places of it obscurity and doubtfulness".
Theory of knowledge
The Fourth Book, about Knowledge proper and Probability, closes the Essay. Knowledge, he says, is perception of relations among ideas; it is expressed in our affirmations and negations; and real knowledge is discernment of the relations of ideas to what is real. In the foregoing part of the Essay he had dealt with "ideas" and "simple apprehension", here he is concerned with intuitive "judgment" and demonstrative "reasoning", also with judgments and reasonings about matters of fact. At the end of this patient search among our ideas, he supposes the reader apt to complain that he has been "all this while only building a castle in the air", and to ask what the purpose of all this stir is, if we are not thereby carried beyond mere ideas. "If it be true that knowledge lies only in the agreement or disagreement of ideas, the visions of an enthusiast and the reasonings of a sober man will be equally certain. It is no matter how things themselves are" (bk. iv. 4). This gives the keynote to the fourth book. It does not, however, carry him into a critical analysis of the rational constitution of knowledge, like Kant. Hume had not yet shown the skeptical objections against conclusions which Locke accepted without criticism. The subtle agnostic, who doubted reason because reason could not be supported in the end by empirical evidence, was less in his view than persons blindly resting on authority or prejudice. Total skepticism he would probably have regarded as unworthy of the serious attention of a wise man. "Where we perceive the agreement or disagreement of any of our ideas there is certain knowledge; and wherever we are sure these ideas agree with the reality of things, there is certain real knowledge" (bk. iv. ch. 4).
Four sorts of knowable relations
Locke's report about human knowledge and its narrow extent forms the first thirteen chapters of the fourth book. The remainder of the book is concerned for the most part with the probabilities on which human life practically turns, as he and Butler are fond of reminding us. As regards kinds of knowledge, he finds that "all knowledge we are capable of" must be assertion or denial of some one of three sorts of relation among our ideas themselves, or else of relations between our ideas and reality that exists independently of us and our ideas. Accordingly, knowledge is concerned either with (a) relations of identity and difference among ideas, as when we say that "blue is not yellow"; or (b) with mathematical relations, as that "two triangles upon equal bases between two parallels must be equal"; or (c) in assertions that one quality does or does not coexist with another in the same substance, as that "iron is susceptible of magnetical impressions, or that ice is not hot"; or (d) with ontological reality, independent of our perceptions, as that "God exists" or "I exist" or "the universe exists". The first sort is analytical; mathematical and ethical knowledge represents the second; physical science forms the third; real knowledge of self, God and the world constitutes the fourth.
Intuition and demonstration
Locke found important differences in the way in which knowledge of any sort is reached. In some instances the known relation is self-evident, as when we judge intuitively that a circle cannot be a triangle, or that three must be more than two. In other cases the known relation is perceived to be intellectually necessary through the medium of premises, as in a mathematical demonstration. All that is strictly knowledge is reached in these two ways. But there is a third sort, namely sense-perception, which hardly deserves the name. For "our perceptions of the particular existence of finite beings without us" go beyond mere probability, yet they are not purely rational. There is nothing self-contradictory in the supposition that our perceptions of things external are illusions, although we are somehow unable to doubt them. We find ourselves inevitably "conscious of a different sort of perception", when we actually see the sun by day and when we only imagine the sun at night.
Locke next inquired to what extent knowledge—in the way either of intuitive certainty, demonstrative certainty, or sense perception—is possible, in regard to each of the four (already mentioned) sorts of knowable relation. There is only one of the four in which our knowledge is co-extensive with our ideas. It is that of "identity and diversity": we cannot be conscious at all without distinguishing, and every affirmation necessarily implies negation. The second sort of knowable relation is sometimes intuitively and sometimes demonstrably discernible. Morality, Locke thinks, as well as mathematical quantity, is capable of being demonstrated. "Where there is no property there is no injustice", is an example of a proposition "as certain as any demonstration in Euclid". Only we are more apt to be biassed, and thus to leave reason in abeyance, in dealing with questions of morality than in dealing with problems in mathematics.
Turning from abstract mathematical and moral relations to concrete relations of coexistence and succession among phenomena—the third sort of knowable relation—Locke finds the light of pure reason disappear; although these relations form "the greatest and most important part of what we desire to know". Of these, including as they do all inductive science, he reports that demonstrable knowledge "is very short, if indeed we have any at all"; and are not thrown wholly on presumptions of probability, or else left in ignorance. Man cannot attain perfect and infallible science of bodies. For natural science depends, he thinks, on knowledge of the relations between their secondary qualities on the one hand, and the mathematical qualities of their atoms on the other, or else "on something yet more remote from our comprehension". Now, as perception of these atoms and their relations is beyond us, we must be satisfied with inductive presumptions, for which "experimental verification" affords, after all, only conclusions that wider experience may prove to be inadequate. But this moral venture Locke accepts as "sufficient for our purposes".
Our knowledge under Locke's fourth category of relations—real existence—includes (a) intuitive perceptions of our own existence; (b) demonstrable certainty of the existence of God; and (c) actual perception of the existence of surrounding things, as long as, but only as long as the things are present to sense. "If I doubt all other things, that very doubt makes me perceive my own existence, and will not suffer me to doubt of that" (iv. 9. 3). Faith in the existence of God is virtually with Locke an expression of faith in the principle of active causality in its ultimate universality. Each person knows that he now exists, and is convinced that he had a beginning; with not less intuitive certainty he knows that "nothing can no more produce any real being than it can be equal to two right angles". His final conclusion is that there must be eternally "a most powerful and most knowing Being, in which, as the origin of all, must be contained all the perfections that can ever after exist", and out of which can come only what it has already in itself; so that as the cause of my mind, it must be Mind. There is thus causal necessity for Eternal Mind, or what we call "God". This is cautiously qualified thus in a letter to Anthony Collins, written by Locke a few months before he died: "Though I call the thinking faculty in me 'mind,' yet I cannot, because of that name, equal it in anything to that infinite and incomprehensible Being, which, for want of right and distinct conceptions, is called 'Mind' also". But the immanence of God in the things and persons that compose the universal order, with what this implies, is a conception foreign to Locke, whose habitual conception was of an extra-mundane deity, the dominant conception in the 18th century.
Knowledge of the external world
Turning from our knowledge of Spirit to our knowledge of Matter, nearly all that one can affirm or deny about "things external is", according to Locke, not knowledge but venture or presumptive trust. We have, strictly speaking, no "knowledge" of real beings beyond our own self-conscious existence, the existence of God, and the existence of objects of sense as long as they are actually present to sense. "When I see an external object at a distance, a man for instance, I cannot but be satisfied of his existence while I am looking at him. (Locke might have added that when one only 'sees a man' it is merely his visible qualities that are perceived; his other qualities are as little 'actual present sensations' as if he were out of the range of sense.) But when the man leaves me alone, I cannot be certain that he still exists". "There is no necessary connection between his existence a minute since (when he was present to any sense of sight) and his existence now (when he is absent from all my senses); by a thousand ways he may have ceased to be. I have not that certainty of his continued existence which we call knowledge; though the great likelihood of it puts it past doubt. But this is but probability and not knowledge" (chap. 11, § 9). Accordingly, purely rational science of external Nature is, according to Locke, impossible. All our "interpretations of nature" are inadequate; only reasonable probabilities, not final rational certainties. This boundless region affords at the best probabilities, ultimately grounded on moral faith, all beyond lies within the veil. Such is Locke's "plain, matter-of-fact" account of the knowledge of the Real that is open to man.
The rationale of probability
We learn little from Locke as to the rationale of the probabilities on which man thus depends when he deals with the past, the distant or the future. The concluding chapters of the fourth book contain wise advice to those whose lives are passed in an ever-changing environment, for avoiding the frequent risk of error in their conclusions, with or without the help of syllogism, the office of which, as a means of discovery, is here critically considered.
Locke and Hume
Investigation of the foundation of inductive inference was resumed by Hume where Locke left it. With a still humbler view of human reason than Locke's, Hume proposed as "a subject worthy of curiosity", to inquire into "the nature of that evidence which assures us of any real existence and matter of fact, beyond the present testimony of our senses and the records of our memory; a part of philosophy that has been little cultivated either by the ancients or the moderns". Hume argues that custom is a sufficient practical explanation of this gradual enlargement of our objective experience, and that no deeper explanation is open to man. All beyond each present transitory "impression" and the stores of memory is therefore reached blindly, through custom or habitual association. Associative tendency, individual or inherited, has since been the favorite constructive factor of human experience in Empirical Philosophy. This factor is not prominent in Locke's Essay. A short chapter on "association of ideas" was added to the second book in the fourth edition. And the tendency to associate is there presented, not as the fundamental factor of human knowledge, but as a chief cause of human error.
Locke and Kant
Kant's critical analysis of pure reason is more foreign to Locke than the attempts of 18th- and 19th-century associationists and evolutionists to explain experience and science. Kant's aim was to show the necessary rational constitution of experience. Locke's design was less profound. It was his distinction to present to the modern world, in his own "historical plain method", perhaps the largest assortment ever made by any individual of facts characteristic of human understanding. Criticism of the presuppositions implied in those facts—by Kant and his successors, and in Britain more unpretentiously by Reid, all under the stimulus of Hume's skeptical criticism—has employed philosophers since the author of the Essay on Human Understanding collected materials that raised deeper philosophical problems than he tried to solve. Locke's mission was to initiate modern criticism of the foundation and limits of our knowledge. Hume negatively, and the German and Scottish schools constructively, continued what it was Locke's glory to have begun.
Bibliography.—The Essay concerning Human Understanding has passed through more editions than any classic in modern philosophical literature. Before the middle of the 18th century it had reached thirteen, and it has now passed through some forty editions, besides being translated into Latin, French, Dutch, German and modern Greek. There are also several abridgments. In addition to those criticisms which appeared when Locke was alive, among the most important are Leibnitz's Nouveaux Essais sur l'entendement humain—written about 1700 and published in 1765, in which each chapter of the Essay of Locke is examined in a corresponding chapter by Leibnitz; Cousin's "École sensualiste: système de Locke", in his Histoire de la philosophie au XVIIIe siècle (1829); and the criticisms in T. H. Green's Introduction to the Philosophical Works of Hume (1874). The Essay, with Prolegomena, biographical, critical and historical, edited by Professor Campbell Fraser and published by the Oxford Clarendon Press in 1894, is the only annotated edition, unless the Nouveaux Essais of Leibnitz may be reduced to this category.
The Letters on Toleration, Thoughts on Education and The Reasonableness of Christianity have also gone through many editions, and been translated into different languages.
The first collected edition of Locke's Works was in 1714, in three folio volumes. The best is that by Bishop Law, in four quartos (1777). The one most commonly known is in ten volumes (1812).
The Éloge of Jean le Clerc (Bibliothèque choisie, 1705) has been the basis of the memoirs of Locke prefixed to the successive editions of his Works, or contained in biographical dictionaries. In 1829 a Life of Locke (2nd ed. in two volumes, with considerable additions, 1830), was produced by Peter, 7th Baron King, a descendant of Locke's cousin, Anne Locke. This adds a good deal to what was previously known, as Lord King was able to draw from the mass of correspondence, journals and commonplace books of Locke in his possession. In the same year Dr. Thomas Foster published some interesting letters from Locke to Benjamin Furly. The most copious account of the life is contained in the two volumes by H. R. Fox-Bourne (1876), the results of laborious research among the Shaftesbury Papers, Locke manuscripts in the British Museum, the Public Record Office, the Lambeth, Christ Church and Bodleian libraries, and in the Remonstrants' library at Amsterdam. Monographs on Locke by T. H. Fowler in 1880, in "English Men of Letters", and by Fraser, in 1890, in Blackwood's "Philosophical Classics" may be mentioned; also addresses by Sir F. Pollock and Fraser at the bicentenary commemoration by the British Academy of Locke's death, published in the Proceedings of the Academy (1904). See also C. Bastide, John Locke; ses théories politiques et leur influence en Angleterre (Paris, 1907); H. Ollion, La Philosophie générale de J. L. (1909).
Coste, Pierre. "The Character of Mr. Locke; in a letter to the author of the Nouvelles de la Republique des Lettres by Mr. P. Coste", A Collection of Several Pieces of Mr. John Locke. R. Francklin, London, 1739. p. vii.