John Locke un resumen de sus tesis filosóficas (inglés)


LOCKE, JOHN (1632-1704), English empiricist and moral and political philosopher. He was born in Wrington, Somerset. Locke’s father, an attorney and for a time a clerk to the justices of the peace in Somerset, fought on the parliamentary side in the first rebellion against Charles I. Locke was reared in a liberal Puritan family and early learned the virtues of temperance, simplicity, and aversion to display. Though his father was severe and remote from him in early youth, as Locke matured they became close friends.

In 1646 Locke entered Westminster School, where he studied the classics, Hebrew, and Arabic. Little time was given at Westminster to science and other studies, and its harsh discipline, rote learning, and excessive emphasis on grammar and languages were later condemned by Locke.

In 1652 Locke was elected to a studentship at Christ’s Church, Oxford. He received his B.A. in 1656 and remained in residence for the master’s degree. He was not happy with the study of Scholastic philosophy and man-aged to inform himself of many new areas of thought. As a master, Locke lectured in Latin and Greek and in 1664 was appointed censor of moral philosophy.

His father’s death in 1661 left Locke with a small inher-itance and some independence. During these years he became acquainted with many men who were to have a profound influence upon his life. From Robert Boyle Locke learned about the new sciences and the corpuscular theory, as well as the experimental and empirical methods. Confronted with the choice of taking holy orders, continu-ing as a don, or entering another faculty, Locke chose medicine. Though well trained, he never practiced medi-cine, nor was he permitted to take the medical degree, which would have permitted him to teach the profession, until 1674, although in 1667 he began to collaborate with the great physician Thomas Sydenham, who deeply influenced him.

In 1665 Locke was sent on a diplomatic mission accom-panying Sir Walter Vane to the elector of Brandenburg at Cleves. He subsequently rejected a secretaryship under the earl of Sandwich, ambassador to Spain, and returned to Oxford. It was at this time that his interests began to turn seriously to philosophy. Descartes was the first philoso-pher whom Locke enjoyed reading and the first to show him the possibility of viable alternatives to the Schoolmen.

Locke had met Lord Ashley, earl of Shaftesbury, in 1662 at Oxford. They found much pleasure in each other’s com-pany, and the astute Shaftesbury quickly recognized Locke’s talents. In 1667 he invited Locke to live with him in London as his personal physician. Later Locke served him well in many other capacities. Under Shaftesbury Locke found himself in the center of the political and practical affairs of the day. He assisted Shaftesbury in the framing of a constitution for the colony of Carolina. For a time he was secretary for the presentation of benefices and then secretary to the Council of Trade and Plantations. Locke was always at home in the world of practical affairs, and many of his philosophical attitudes reflect this interest. At the same time he became a fellow in the Royal Society, where he continued to be in touch with learning.

Locke, never robust in health, in 1675 went on a pro-longed visit to France, where he made many friends and came into contact with the foremost minds of his day. His studies and criticisms of Descartes were deepened under the influence of various Gassendists.

In 1679 Locke returned to an England torn by intense political conflicts. Shaftesbury, who had become the leader of the parliamentary opposition to the Stuarts, alternated between political power and impotence. The close asso-ciation with Shaftesbury brought Locke under suspicion; he was kept under surveillance. Shaftesbury was tried for treason in 1681, but acquitted. He subsequently fled Eng-land for Holland, where he died in 1683. Locke, at Oxford, uncertain of his position and fearing persecution, also fled England, arriving in Holland in September 1683. The king had demanded that Locke be deprived of his studentship at Oxford, and news of this demand caused Locke to pro-long his stay. After the death of Charles II and the ascen-sion of James II to the throne, the duke of Monmouth attempted a rebellion, which failed. Locke was denounced as a traitor, and the crown demanded of the Dutch that he be returned to England. No great effort was made to comply with the demand, and Locke remained in Holland.

During his stay in Holland, Locke again acquired a wide circle of distinguished friends and wrote extensively. He contributed an article as well as reviews to the Biblio-theque universelle of Jean Leclerc; these were his first pub-lished works. He wrote in Latin the Epistola de Toleran-tia, which was published anonymously in 1689 and translated as the First Letter Concerning Toleration. He also worked assiduously on the Essay Concerning Human Understanding, which he had been writing off and on since 1671. In 1688 the Bibliotheque universelle published an abstract of the Essay.

These activities did not prevent him from being deeply engaged in politics. The plot to set William of Orange on the throne of England was well advanced in 1687, and Locke was, at the very least, advising William in some capacity. The revolution was accomplished in the fall of 1688, and in February 1689 Locke returned to England, escorting the princess of Orange, who later became Queen Mary.

In 1689 and 1690 Locke’s two most important works, the Essay Concerning Human Understanding and the Two Treatises of Government, were published. From 1689 to 1691 Locke shuttled between London and Oates, the home of Sir Francis and Lady Masham, the daughter of Ralph Cudworth. He had declined an ambassadorial post only to accept a position as commissioner on the Board of Trade and Plantations. Apparently his practical wisdom was invaluable, for when he wished in 1697 to resign because of ill health, he was not permitted to do so. He remained until 1700, serving when he could, although his health was extremely poor.

In 1691 Locke made Oates his permanent residence at the invitation of Lady Masham. It was, for the aging Locke, a place of refuge and joy; there he received visits from Newton, Samuel Clarke, and others. These were produc-tive years for Locke. Some Thoughts Concerning Educa-tion appeared in 1693. The second edition of the Essay was published in 1694. In the following year the Reasona-bleness of Christianity was published anonymously. He answered criticism of it in A Vindication of the Reasonableness of Christianity (London, 1695) and in a second Vindication in 1697. From 1697 to 1699 Locke engaged in an epistolary controversy with Edward Stillingfleet, bishop of Worcester.

However, Locke’s health steadily failed him. After 1700, when the fourth edition of the Essay appeared, he re-mained almost constantly at Oates. He was engaged in editing the Two Treatises of Government, for no edition which pleased him had yet appeared. In his last years he wrote extensive commentaries on the epistles of St. Paul, which were published posthumously. On October 28, 1704, while Lady Masham was reading the Psalms to him, Locke died. Lady Masham wrote of him, “His death was like his life, truly pious, yet natural, easy and unaffected.”

Character. The Lovelace Collection of Locke’s personal papers in the Bodleian Library, Oxford, shows that Locke’s character and personality were more complex than had been suspected. The great affection and respect which so many men and women had for him are testimony to his charm and wisdom. That he was modest, prudent, pious, witty, and eminently practical was long known. But he was also extremely secretive and apparently given to excessive suspicion and fears. When his lifelong friend, James Tyrrell, voiced his suspicion that Locke had written the Two Treatises, Locke was evasive and would not admit the fact. When he suspected that Tyrrell was spreading the report that Locke was the author, Locke angrily demanded an explanation. At the same time, Locke showed great affection for many friends and a real fondness for children. In maturity he could not abide religious intolerance or suffer tyranny. He was passionately devoted to truth and strove constantly to state the truth as he saw it, but always with a caution that distrusted all dialectic, even his own, when it appeared to go beyond common sense.

Influences on Locke. Locke’s philosophy is grounded in medieval thought, though he, like Descartes, turned away from it as far as possible. The Cambridge Platonists, nota-bly Ralph Cudworth and Benjamin Whichcote, influenced him greatly with respect to religious tolerance, empirical inquiry, and the theory of knowledge. Locke was indebted to Richard Hooker in his political thought. Hobbes proba-bly influenced him somewhat, though Locke was con-cerned not to be classed as a Hobbist. The two most im-portant philosophical influences upon him were Descartes and Pierre Gassendi. From Descartes he learned much that is incorporated in the Essay, and in Gassendi and the Gassendists he found support to challenge the doctrine of innate ideas and the radical rationalistic realism of Des-cartes. Gassendi helped to convince Locke both that knowledge begins in sensation and that intellect, or rea-son, is essential to the attainment of truth and knowledge.


Locke’s position in the history of Western thought rests upon The Essay Concerning Human Understanding and Two Treatises of Government. He spent long years work-ing out the thought of each, and he carefully and lovingly revised and corrected them for subsequent editions. Locke wrote two drafts of his Essay in 1671, and in 1685 he wrote a third. The first edition, though dated 1690, appeared in late 1689. During the years between 1671 and 1689 Locke revised and reorganized many of his original concepts. In response to criticisms of the first edition of the Essay, he introduced a number of changes in subsequent editions. This long period of gestation and Locke’s subsequent modifications of his initial public statement disclose pri-marily the refinement and clarification of his philosophy by way of certain important additions, but never by a radical or fundamental departure from his basic position.

From the first appearance of the Essay Locke was criti-cized for being inconsistent in his theory of knowledge, vague in the presentation and development of many of his ideas, and wanting in thoroughness in developing other ideas. But these criticisms have in no way dimin-ished either the importance or the influence of the Essay on subsequent thinkers. By no means the first of the British empiricists, Locke nonetheless gave empiricism its firmest roots in British soil, where it still proudly flourishes. It must be remembered that Locke was also a rationalist, though one of quite different orientation from such Conti-nental thinkers as Descartes, Spinoza, and Malebranche. In Locke many strands of traditional thought are rewoven into a new fabric. Subsequent thinkers, notably Berkeley, Hume, and Kant, perhaps fashioned more coherent and consistent systems, but it is doubtful whether they were more adequate to what Locke might have called the plain facts. Locke’s tendency toward inconsistency can be seen in his definition of knowledge as “the perception of the connection and agreement, or disagreement and repug-nancy, of any of our ideas” (Essay, IV.i.2). This is plainly incompatible with his later contention that we have intui-tive knowledge of our own existence, demonstrative knowledge of God’s existence, and sensitive knowledge of the existence of particular things. Nonetheless, Locke would not abandon his position for the sake of consistency alone. He was persuaded that common sense and the facts justified his conviction and that whatever faults there were in his position lay in the difficulty of stating a coherent theory of knowledge, not in the reality of things. If this made him an easy prey to a skillful dialectician, like Berkeley, it also left him closer to the common conviction of most of us when we think about anything other than epistemology. It is this viewpoint, almost unique in phi-losophy, that accounts for the abiding interest in Locke’s thought and the great extent of his influence despite the shortcomings of his work.

Purpose of the “Essay.” In the “Epistle to the Reader” Locke related that some friends meeting in his chamber became perplexed about certain difficulties that arose in their discourse about a subject (left unnamed). He pro-posed that before they could inquire further, “it was nec-essary to examine our own abilities and see what objects our understandings were, or were not, fitted to deal with.” This discussion in 1670 or 1671 first started Locke on the inquiries that were to continue intermittently for twenty years. What Locke first set down for the next meeting is not known, unless it was Draft A (1671) of the Essay. That the initial suggestion became the abiding purpose of the Essay is clear from Locke’s assertion that his purpose was “to inquire into the original, certainty, and extent of hu-man knowledge, together with the grounds and degrees of belief, opinion, and assent” (I.i.2). At the same time he disavowed any intention to examine “the physical consid-eration of the mind, . . . wherein its essence consists, or by what motions of our spirits or alterations of our bodies we come to have any sensation by our organs or any ideas in our understandings, and whether those ideas do in their formation any or all of them depend on matter or no” (I.i.2).

Locke did not, in fact, offer any detailed or explicit ac-counts of these matters. He would have considered that a subject for natural philosophy. Nonetheless, he did, as indeed he had to, deal with the physical considerations of the mind, as well as all the other matters mentioned.

From the outset Locke was persuaded that our under-standing and knowledge fall far short of all that exists; yet he was equally certain that men have a capacity for knowledge sufficient for their purposes and matters enough to inquire into. These convictions, pragmatic and utilitarian, set Locke apart from most of the other major philosophers of the seventeenth century, who, impressed by the new developments in mathematics and the new physical sciences, boldly plunged ahead with a rationalis-tic realism in the belief that their new methods would enable them in large measure to grasp reality. Locke saw that the very advances made in the new sciences put real-ity farther from the reach of the human mind. This did not make Locke a nominalist or an idealist in any modern sense; rather, he persistently affirmed the real objective existence of things or substances. What he denied was that the human understanding could know with certainty the real essences of substances. If “ideas” stand between reality and the understanding, it is to link them, even if only under the form of appearances. It is not to obliterate any connection between them or to justify a negation of substance — God, mind, or matter.

Ideas. The key term in Locke’s Essay is “idea,” which he defined as “. . . whatsoever is the object of the under-standing when a man thinks, . . . whatever is meant by phantasm, notion, species, or whatever it is which the mind can be employed about in thinking” (I.i.8). Any object of awareness or of consciousness must be an idea. But then how can we have any knowledge of anything other than ideas and their relationships? It is true that Locke spoke of ideas as the “materials of knowledge.” Yet knowledge itself, when possessed and made the object of the mind, must be an idea. For example, to perceive that A is equal to B is to perceive the agreement between A and B. This agreement as perceived must be an idea, or it cannot be an object of the mind when it thinks. Despite this difficulty Locke clung tenaciously to his term “idea” in his disputes with Stillingfleet. He actually intended something other than he stated, namely, that knowledge is an operation, an activity of the mind, not initially one of its objects. It would have served his purpose better had he spoken of “knowing” rather than of “knowledge,” even though this would not have entirely removed the difficulty, since to set the mind at a distance where we may look at it, in order to know what knowledge is, is still to have an idea.

Locke, however, went beyond ideas to assume the real existence of things, substances, actions, processes, and operations. Ideas, except when they are the free constructs of the mind itself, signify and represent, however imper-fectly, real existences and events. So deep was Locke’s conviction on this point that no argument could shake him, although he constantly tried to remove the difficulties implicit in his definitions of “ideas” and “knowledge.” This conviction is evident in the first two books of the Essay, in which Locke inquired into the origin of our ideas.

No innate ideas. It was Locke’s central thesis, devel-oped extensively in Book II of the Essay, that we get all our ideas from experience. The whole of the first book is given to an overlong criticism, at times not germane to the subject, of the doctrine that we have innate ideas and innate knowledge.

Locke contended that there are no innate principles stamped upon the mind of man and brought into the world by the soul. In the first place, the argument that people have generally agreed that there are innate ideas, even if true, would not demonstrate the innateness of ideas. Moreover, there are no principles to which all give assent, since principles such as “Whatever is, is” and “It is im-possible for the same thing to be and not to be” are not known to children, idiots, and a great part of mankind, who never heard or thought of them. Locke here assumed that innateness was equivalent to conscious perceiving and argued that to be in the mind is to be perceived or to be readily recalled to perception. Locke allowed that there is a capacity in us to know several truths but contended that this lent no support to the argument that they are innate.

To argue that all men know and assent to certain truths when they come to the use of reason proves nothing, since they will also come to know many truths that are not in-nate. It would appear, then, that all truth is either innate or adventitious. Again, why should the use of reason be necessary to discover truths already innately in the mind? Locke allowed that the knowledge of some truths is in the mind very early, but observation shows such truths are about particular ideas furnished by the senses; for exam-ple, a child knows the difference between the ideas of sweet and bitter before it can speak and before it knows abstract ideas. Even assent at first hearing is no proof of innateness, for many truths not innate will be assented to as soon as understood.

On the contrary, the senses first furnish us with particu-lar ideas, which the mind by degrees becomes familiar with, remembers, and names. The mind subsequently abstracts from these particular ideas and gives names to general ideas. Thus, general ideas, general words, and the use of reason grow together, and assent to the truth of propositions depends on having clear and distinct ideas of the meaning of terms. Locke held it to be evident that particular propositions are known before the more univer-sal and with as much certainty.

We have natural faculties or capacities to think and to reason. This is not, however, the same thing as having innate ideas, for if anyone means by innate ideas nothing but this natural capacity, he uses terms, according to Locke, in a manner plainly contrary to common usage.

In a similar fashion, Locke argued that we have no in-nate moral or practical principles, for there is no universal agreement about such principles; great varieties of human vice have been at one time or place considered virtues. We all have a desire for happiness and an aversion to misery, but these inclinations give us no knowledge or truth. Locke was persuaded that there are eternal principles of morality, which men may come to know through the use of reason about experience. This, however, is far from proving them innate.

In the third chapter of Book I Locke argued that no prin-ciples can be innate unless the ideas contained in them are innate, that is, unless men can be conscious of them. Im-possibility and identity are hardly innate, yet without them we cannot understand the supposedly innate principle of identity, that it is impossible for the same thing both to be and not be. Similarly, the proposition that God is to be wor-shipped cannot be innate, for the notion of God is so diverse that men have great difficulty agreeing on it, while some men have no conception of God whatsoever.

Locke’s target. Who was Locke criticizing in his long and repetitious attack on the doctrine of innate ideas? Was the position he denounced held by anyone in the form in which he presented the theory? Why did he examine the question at such length?

Since the Essay was first published tradition has held that Locke’s target was Descartes and the Cartesians. Cer-tainly Leibniz thought so, as did others after him. In the late nineteenth century, critics pointed to Locke’s own rationalism and noted that his recognition of men’s natural faculties and innate powers to think and reason is not far from the position of Descartes, who wrote, “Innate ideas proceed from the capacity of thought itself,” and “I never wrote or concluded that the mind required innate ideas which were in some sort different from its faculty of think-ing.” Various other possible objects of Locke’s attacks were suggested, the Cambridge Platonists, certain groups in the universities, and various clergymen. Recently R. I. Aaron has argued persuasively that the older tradition, that Descartes, the Cartesians, and certain English thinkers were the targets of Locke’s attack, is the correct one and that Locke was not simply striking at a straw man of his own making.

Reasons for attacking innate ideas. Locke suggested that the doctrine of innate ideas lends itself to a certain author-itarianism and encourages laziness of thought, so that the foundations of knowledge are not likely to be examined. The expression “innate ideas” is an unfortunate one and admittedly extremely vague. It carries with it the sugges-tion that certain ideas and knowledge are, in Locke’s sense, imprinted on the mind and are in no way dependent on experience. Certainly there are passages in Descartes which strongly suggest that certain ideas are innately in the mind, and more than a few thinkers took this to be Descartes’s meaning. Furthermore, Locke wished to pre-pare the ground for his own thesis that all ideas and all knowledge are acquired. If he overemphasized the crude sense of the theory of innate ideas, he also showed that even the refined doctrine is unnecessary in accounting for knowledge.

There is another point that Locke discussed later in the Essay. Descartes asserted that the essence of the mind is to think. To Locke this meant that the mind could not both be and not think. He argued that the mind does not think always and that its real essence cannot be thinking. If the mind thinks always, either some ideas must be innate or the mind comes into being only after it has been furnished with ideas by experience. Neither alternative was accepta-ble to Locke.

Source of ideas. Locke, in his positive thesis in Book II, valiantly and sometimes awkwardly endeavored to show that every idea we have is ultimately derived from experi-ence, either from sensation or reflection. Locke began by asserting that a man is conscious of two things, the fact “that he thinks” and “the ideas” in the mind about which he thinks. Locke’s initial concern was with the question of how a man comes by his ideas; and he made an assump-tion in terms of several similes. “Let us then suppose the mind to be, as we say, white paper, void of all characters, without any ideas. How comes it to be fur-nished? . . . Whence has it all the materials of reason and knowledge?” (II.i.2). Locke replied to his own questions that we get all our ideas from experience, the two fountainheads of which are sensation and reflection. Our senses are affected by external objects (bodies) and afford us ideas, such as yellow, white, heat, cold, soft, hard, bitter, and sweet. Perceiving the operations of our own minds when we reflect, we are furnished with ideas of percep-tion, thinking, doubting, believing, reasoning, knowing, and willing.

The ideas that are furnished by experience are the ma-terials of reason and knowledge. These materials are either the immediate objects of sense, such as color, or the unex-amined but direct awareness of such acts as doubting or knowing. Locke’s meaning becomes explicitly clear in his account of solidity. He held that we get the idea of solidity by touch. “That which … hinders the approach of two bodies, when they are moving one towards another, I call solidity” (II.iv.1). He sharply distinguished this sense from the purely mathematical use of the term. Impenetrability is an acceptable alternative name for solidity. It is clearly distinct from space and hardness. After an extensive dis-cussion Locke stated, “If anyone asks me what this solidity is, I send him to his senses to inform him. Let him put a flint or a football between his hands and then endeavour to join them, and he will know” (II.iv.6). All philosophical and scientific discourse about solidity, however complex and sophisticated it may be, must ultimately refer back to that from which it began, namely the experience or sensa-tion we have when we put something such as a flint or a football between our hands. Similarly, we cannot by dis-course give a blind man the idea of color or make known what pain is to one who never felt it. All knowledge about the physics of light and color or sound refers back to what we perceive when we see and hear. It is in this sense, then, that we get all our ideas from sensation and reflection. Locke nowhere, however, suggested that we can or should stop there. Once the mind is furnished with ideas, it may perform various operations with them.

Ideas and the real world. Throughout the first book of the Essay Locke assumed the real existence of an external physical world and the substantial unity of a man in body and mind. He undoubtedly accepted the thesis that the external physical world is corpuscular and acts by bodies in motion that possess only those qualities which Locke called primary. Locke spoke of secondary qualities as powers in bodies to produce in our minds ideas that are signs of these powers but that in no way resemble the powers which produce them. Often he suggested that if we had the means of observing the minute motions of the particles making up gross bodies, we might have a clearer notion of what we mean when we call secondary qualities powers. Locke’s position here is physical realism. It is not simply a manner of speaking. The ideas we have do represent real things outside of us and do constitute the links by which we know something of the external physical world.

Identity. Among the bodies that exist are those of plants, animals, and men. Existence itself constitutes the principle of individuation. Identity is not applied in the same way to a mass of matter and a living body. The identity of an oak lies in the organization of its parts, which partake of one common life. So it is with animals. Again, “the identity of the same man consists: viz, in nothing but a participation of the same continued life, by constantly fleeting particles of matter, in succession vitally united to the same organized body” (II.xxvii.6).

Origin of sensation. With these controlling hypotheses in the Essay in view, we may return to Locke’s invitation to consider the mind as a blank sheet of paper without any ideas. Is a mind without ideas anything but a bare capacity to receive ideas? If we ask what a man is without ideas, we can say he is an organized body existing in a world of other bodies and interacting with them. Experience is a matter of contact of the organized human body with other bodies before it is a matter of sensation or perception. Not every body impinging on our body gives rise to sensation; if it does not, we take no notice of it. However, if some external bodies strike our senses and produce the appropriate mo-tions therein, then our senses convey into the mind several distinct perceptions. How this takes place Locke avoided considering, but that it takes place he was certain; a man, he asserted, first begins to think “when he first has any sensation” (II.i.23).

Simple and complex ideas. Locke proceeded to distin-guish between simple and complex ideas. A simple idea is “nothing but one uniform appearance or conception in the mind, and is not distinguishable into different ideas” (II.ii.1). A color seen, a sound heard, warmth felt, an odor smelled, are all simple ideas of sense. Once it is furnished with a number of simple ideas, the mind has the power to repeat, compare, and unite them into an almost infinite variety of combinations; but it is utterly incapable of in-venting or framing a new simple idea. Thus, with respect to simple ideas the mind is mostly passive; they are simply given in experience. The ideas are given not in isolation from each other but in combinations, as when we simulta-neously feel the warmth and softness of wax or the cold-ness and hardness of ice; nevertheless, simple ideas are distinct from each other in that the mind may mark off each from the other, however united the qualities may be in the things that cause the simple ideas in the mind. Moreover, only those qualities in things that produce ideas in us can ever be imagined at all. Thus, our knowledge of existence is limited by the ideas furnished by experience. Had we one sense less or more than we now do, our experience and knowledge would be respectively decreased or increased.

We have certain ideas, such as color or odor, from one sense only; others, like figure and number, from more than one sense. Reflection alone provides us with experience of thinking and willing. Other ideas, such as pleasure, pain, power, existence, and unity, we have from both sensation and reflection.

Primary and secondary qualities. Locke made a second basic distinction-between primary and secondary quali-ties. In doing so he clearly went beyond ideas. He wrote, “Whatsoever the mind perceives in itself, or is the immedi-ate object of perception, thought, or understanding, that I call idea; and the power to produce any idea in our mind, I call quality of the subject wherein that power is” (II.viii.8). Primary qualities, he argued, are utterly inseparable from body. They are known to be primary because sense con-stantly finds them there if body can be perceived at all, and the mind by critical reflection finds them inseparable from every particle of matter. Solidity, extension, figure, and mobility are all primary qualities. Our ideas of these qualities resemble the qualities themselves, and these qual-ities really exist in body, whether or not they are per-ceived. Berkeley was to show that to speak of resemblance supposes that a comparison, an observation, can be made. Locke was aware of the difficulty, as is shown in his Exam-ination of Malebranche. Apparently he believed it was the only explanation plausible in spite of its difficulties.

Secondary qualities, in Locke’s terms, were nothing but powers to produce various sensations. Bodies do so by the action of their bulk, figure, and texture, and by the motion of their insensible parts on our senses. Somehow they produce in us such ideas as color, odor, sound, warmth, and smell. These ideas in no way resemble the qualities of bodies themselves. They are but signs of events in real bodies. Locke also frequently called these ideas secondary qualities. He would have been clearer had he called them sensory ideas of secondary qualities, preserving the dis-tinction between qualities as attributes of a subject and ideas as objects in the mind. A third class of qualities (sometimes called tertiary) is the power of a body to pro-duce a change in another body, for example, the power of the sun to melt wax.

Nowhere is Locke’s physical realism more evident than in his distinction between primary and secondary quali-ties. Whatever epistemological difficulties the distinction might entail, Locke was persuaded that the new physics required it. Indeed, the distinction was made by Boyle, Descartes, Galileo, and others before him and was thor-oughly familiar in his day. Admittedly there is a problem in the assertion that a certain motion in body produces in us the idea of a particular color. Nevertheless, Locke was persuaded that it was so. In such difficult cases Locke fell back upon the omnipotence and wisdom of God and the fact that our knowledge is suited to our purpose.

Ideas of reflection. Locke observed that perception is the first faculty of the mind and without it we know noth-ing else. Hence, the idea of perception is the first and simplest idea we have from reflection. What perception is, is best discovered by observing what we do when we see, hear, or think. Locke added that judgment may alter the interpretation we make of the ideas we receive from sen-sation. Thus, if a man born blind gains his sight, he must learn to distinguish between a sphere and a cube visually, though he can do so readily by touch. By habit the ideas of sensation are gradually integrated into the unified experi-ence of complex ideas, and by judgment we come to ex-pect things that look a certain way to also feel or smell a certain way. It is worth noting that Locke was persuaded that animals have perception and are not, as Descartes held, mere automatons.

Memory and contemplation. The second faculty of the mind that Locke held indispensable to knowledge is the retention manifested in both contemplation and memory. Contemplation consists in holding an idea before the mind for some time. Memory, however, gave Locke some difficulties. He asserted that “our ideas being nothing but actual perceptions in the mind-this laying up of our ideas in the repository of the memory signifies no more but this: that the mind has a power in many cases to revive perceptions which it has once had, with this additional percep-tion annexed to them, that it has had them before” (II.x.2). The inadequacy of this statement is at once evident. It proposes no more than a kind of subjective conviction that may often be in error. Locke’s analysis of memory was more psychological than philosophical. He passed over the consideration of how memory is possible at all and the criteria by which a true memory may be distinguished from a false memory. He did say, however, that attention, repetition, pleasure, and pain aid memory and are the conditions under which memory is strengthened or weak-ened. Again he asserted that animals have memory.

Other ideas of reflection. Other faculties of the mind are discerning and distinguishing one idea from another, com-paring and compounding, naming, and abstracting. Locke considered each point also in respect to animals, holding, for example, that animals compare and compound ideas only to a slight extent and do not abstract ideas at all. At the conclusion of this chapter (II.xi.15) Locke asserted that he thought he had given a “true history of the first begin-nings of human knowledge.”

Complex ideas. Locke next considered complex ideas. Just as the mind observes that several combinations of simple ideas are found together, so too, it can by its own action voluntarily join several simple ideas together into one complex idea. There are three categories of complex ideas-modes, substances, and relations. Modes are dependencies or affections of substances. Simple modes are variations or different combinations of one simple idea, whereas in mixed modes several distinct ideas are joined to make a complex idea. Ideas of substances represent distinct particular things subsisting in themselves. Com-plex ideas of relation consist in comparing one idea with another.

This classification is not entirely satisfactory because ideas of modes invariably entail relations in the broadest sense. Locke seems to have been closer to Aristotle than to modern usage in his employment of the term “relation.” Under modes Locke included space, duration and time, number, infinity, motion, sense qualities, thinking, pleas-ure and pain, power, and certain mixed modes. Under substance he placed the idea of substance in general, the ideas of particular substances, and collective ideas of sub-stances. In the category of relation, he considered a num-ber of ideas, including cause and effect, relations of place and time, identity and diversity, and others that he classified as proportional, natural, instituted, and moral.

The greater number of these concepts have in other philosophies been credited with some a priori and ex-traempirical character. They are not direct objects of sen-sory experience; and they appear to have a certainty not found in the mere coexistence of sensory ideas. They are more abstract and universal than the simple ideas of sen-sation and reflection. Locke’s broad use of the term “ideas” tends to confuse and obscure the distinction be-tween sensory percept and concept. Nevertheless, Locke undertook to show how the mind actively constructs these complex ideas, abstract and conceptual though they may be, out of the materials of knowledge, the simple ideas of sensation and reflection. In this undertaking Locke’s rationalism was most evident, for he held that while the mind constructs complex ideas, it cannot do so arbitrarily. In this sense, Locke could claim for them an objective reality.

The mode of space. Examination here will be limited to only those complex ideas that are most important and difficult. Among modes, only space, duration, number, thinking, and power will be considered. Locke contended that the modifications of a simple idea are as much distinct ideas as any two ideas can be. Space in its first manifesta-tion is a simple idea, since in seeing and touching we immediately perceive a distance between bodies and the parts of bodies. Though the idea of space constantly accompanies other sensory ideas, it is distinguishable from them. All our modes of the idea of space derive from the initial sensory experience. Thus space considered as length is called distance, considered three-dimensionally is capac-ity, considered in any manner is termed extension. Each different distance, especially when measured by stated lengths, is a distinct idea, including the idea of immensity, which consists in adding distance to distance without ever reaching a terminus. So too, figure allows an endless vari-ety of modifications of the simple idea of space. Place is distance considered relative to some particular bodies or frame of reference.

Locke disagreed with Descartes’s assertion that exten-sion is the essence of matter, although he agreed that we cannot conceive of a body that is not extended. But a body has solidity, and solidity is distinct from the notion of space; for the parts of space are inseparable in thought and in actuality and are immovable, whereas a solid body may move and its parts are separable. Descartes’s argument that the physical universe is a plenum was dismissed by Locke as unsound, for there is no contradiction in the conception of a vacuum. If body is not infinite, we can conceive of reaching out beyond the physical limits of the universe to a place unoccupied by matter. The idea of pure space is necessarily infinite, for we can conceive of no limit or terminus to it. Locke professed not to know whether space was a substance or an accident and offered to answer the question when the ideas of substance and accident were clarified. He was more confident of the idea of pure space than he was of the traditional philosophical categories. Locke placed a great load on the simple idea of space, and by the activity of his reason he went beyond the bounds of possible experience.

Duration and time. The idea of duration is broader than that of time. If we consider the train of ideas that passes through our minds, we observe that one idea constantly succeeds another, and so we come by the idea of succes-sion. By reflection we acquire the idea of duration, which we may then apply to motion and sensory ideas. Where there is no perception of the succession of ideas in our minds, there is no sense of time. Locke insisted that mo-tion does not furnish us with the idea of duration, and he directly opposed Aristotle’s definition that “time is the measure of motion with respect to before and after.”

Once we have the idea of duration, we need a measure of common duration. Time is the consideration of duration marked by certain measures such as minutes, hours, days. The most convenient measures of time must be capable of division into equal portions of constantly repeated periods. We cannot be certain of the constancy of motions or of the time spans they measure. Locke was concerned with liber-ating time from motion. Consequently, he argued that we must consider duration itself as “going on in one constant, equal, uniform course; but none of the measures of it which we make use of can be known to do so” (II.xiv.21). Once time is liberated from motion, Locke held, we can conceive of infinite duration even beyond creation. Thus we can expand by endless addition the idea of duration to come to the notion of eternity.

Were it not for the implicit realism of Locke’s arguments, it would be possible to agree with those scholars who have seen in his arguments about duration and expan-sion a vague groping for a position somewhat similar to Kant’s a priori aesthetic. For both men, space becomes the framework of body, and duration or time the structure of the mind, or the inner sense.

Number. The idea of unity is everywhere suggested to the mind, and no idea is more simple. By repeating it we come to the complex modes of number. Once we have learned to perform this operation, we cannot stop short of the idea of infinity. Locke regarded both finite and infinite as modes of quantity. Because we are able to apply the idea of number to space and time, we are capable of con-ceiving of them as infinite. The idea of infinity is essen-tially negative, since we come to it by enlarging our ideas of number as much as we please and discover that there is no reason ever to stop. We may know that number, space, and duration are infinite, but we cannot positively know infinity itself. Locke insisted that however remote from the simple ideas of sensation and reflection these ideas may be, they have their origin in those simple ideas.

The modes of thinking. Locke gave only casual and formal attention to the modes of thinking, such as sensa-tion, remembrance, recollection, contemplation, attention, dreaming, reasoning, judging, willing, and knowing. Equally superficial was his consideration of modes of pleasure and pain, which consisted of little more than definitions of various emotions.

Power. The chapter on power is the longest in the Essay, and Locke felt obliged to rewrite portions of it time and again, for each new edition.

It is evident that power is not perceived as such. Locke observed that the mind, taking note of the changes and sequences of our ideas and “concluding from what it has so constantly observed to have been, that the like changes will for the future be made in the same things, by like agents, and by the like ways . . . comes by that idea which we call power” (II.xxi.1). From this it hardly seems that the idea of power is a simple idea, unless Locke meant no more than that the idea of power is only the observation of the regular order and connection of our ideas. But Locke wrote that “since whatever change is observed, the mind must collect a power somewhere able to make that change, as well as a possibility in the thing itself to receive it” (II.xxi.4). Here the idea of power is a necessary idea of reason, grounded in certain other experiences. Locke never made clear this distinction. He admitted that the idea of power included some kind of relation but insisted that it was a simple idea.

Power is both passive and active. Whether or not matter has any active power, Locke pointed out, we have our idea of active power from the operations of the mind itself. We find by direct observation that we have the power to begin, continue, or stop certain actions of our minds and motions of our bodies. This power we call will, and the actual ex-ercise of this power, volition, or willing. Action is voluntary or involuntary insofar as it is or is not consequent upon the order or command of the mind.

Locke proceeded to explore the ideas of will, desire, and freedom in terms of the idea of power. “The idea of liberty is the idea of a power in any agent to do or forbear any particular action, according to the determination or thought of the mind, whereby either of them is preferred to the other” (II.xxi.8). Where this power is absent, a man is under necessity. Locke consequently dismissed as unin-telligible the question of whether or not the will is free. The only intelligible question is whether or not a man is free. Freedom is one power of an agent and will is another; one power cannot be the power of another. “As far as this power reaches, of acting or not acting, by the determina-tion of his own thought preferring either, so far is a man free” (II.xxi.21). Freedom then, for Locke, was the absence of constraint. If we distinguish will from desire, we cannot make the mistake of thinking the will is free.

What then determines the will with respect to action is some uneasiness in a man that may be called the uneasiness of desire. Good and evil work on the mind but do not determine the will to particular actions. The only thing that can overcome the uneasiness of one desire is the greater uneasiness of another. The removal of uneasiness is the first and necessary step to happiness. Since it is present desire that moves the will to action, good and evil contemplated and known in the mind can move us to ac-tion only when that knowledge is accompanied by a greater uneasiness than any other. Since we have many desires and can have knowledge of desired good in the future as well as feared evil, we can suspend the pursuit of any desire until we have judged it. Thus, government of our passions is possible whenever there is a greater un-easiness in not doing so. This power is the ground on which we hold men responsible for their actions. Good and bad are nothing but pleasure or pain, present or future. Error in choice is usually due to the greater strength of present pleasure or pain in comparison with future pleas-ure and pain. A true knowledge of what contributes to our happiness can influence a choice only when to deviate from that choice would give greater uneasiness than would any other action. Thus it is possible to change the pleas-antness and unpleasantness of various actions by consideration, practice, application, and custom.

Locke’s conception of power, like his ideas of cause and effect, was inadequate and vague. It was both a simple idea and a complex one; it was the notion of regular se-quence and that of efficacious cause; and it was at once given and a priori. The rational and empirical elements in Locke were at war here. Locke was at his best in showing how the word “power” is commonly used. His analysis of the will and freedom was likewise involved in difficulties.

The will is not free and thus man’s actions are determined; but at the same time we can suspend the execution of any desire by our judgment. Locke was aware of these difficulties, but he saw no satisfactory alternative.

Mixed modes. Mixed modes are made by the mind and are exemplified by drunkenness, a lie, obligation, sacri-lege, or murder. To a great degree we get these ideas by the explanation of the words that stand for them.

Substance. Of all the ideas considered by Locke none gave him more difficulty than that of substance, and no-where was his empiricism more in conflict with his ration-alism. The diverse trends of Locke’s thought concerning substance and the problems he raised prepared the ground for Berkeley, Hume, Kant, and many others who struggled with the same questions. At every opportunity throughout the Essay he returned to consider particular substances and the general idea of substance. Locke held that we are conversant only with particular substances through experience; yet his rationalism and realism would not permit him to abandon the general idea of substance.

The mind is furnished with many simple ideas by the senses, and it observes by reflection that certain of them are constantly together. It then presumes that these belong to one thing and for convenience gives them one name. In this way the mind arrives at the complex idea of particular substances, such as gold, which we observe to be yellow and malleable, to dissolve in aqua regia, to melt, and not to be used up in fire. A substance so defined gives us only a nominal definition.

Locke added that “not imagining how these simple ideas can subsist by themselves, we accustom ourselves to sup-pose some substratum wherein they do subsist, and from which they do result; which therefore we call substance” (II.xxiii.1). This idea of a substratum is extremely vague, and Locke called it a “something we know not what.” Our ideas do not reach, and we cannot have, a knowledge of the real essence of substances. Nonetheless, Locke continued to believe that real essences do exist, although our knowledge comes short of them.

Our knowledge of corporeal substances consists of ideas of the primary and secondary qualities perceived by the senses and of the powers we observe in them to affect or be affected by other things. We have as clear an idea of spirit as of body, but we are not capable of knowing the real essence of either. Locke observed that we know as little of how the parts of a body cohere as of how our spirits perceive ideas or move our bodies, since we know nothing of either except our simple ideas of them. Locke even sug-gested that God could if he wished, as far as we know, add to matter the power to think, just as easily as he could add to matter a separate substance with the power to think.

Even our idea of God is based on simple ideas that are enlarged with the idea of infinity. God’s infinite essence is unknown to us. We can only know that he exists.

Relations. The mind can consider any idea as it stands in relation to any other; and thus we come by ideas of relation, such as father, whiter, older. Frequently, the lack of a correlative term leads us to mistake a relative term for an absolute one. Locke distinguished the relation from the things related and appears to have made all relations ex-ternal. Indeed, he held that many ideas of relation are clearer than ideas of substances; for example, the idea of brothers is clearer than the perfect idea of man.

Though there are many ideas and words signifying relations, they all terminate in simple ideas. There is a difficulty here. If the idea of relation is not a simple idea or a combination of simple ideas, then it is distinct from them. Like the general idea of substance, it is a concept derived from reason. No doubt the mind is capable of comparing the relation of one idea with another, but our perception of this operation must have for its object either a simple idea or the operation itself. On this point Locke was obscure and evasive and avoided the difficulties by the vague assertion that all relations terminate in simple ideas.

Causation. The relation to which Locke first turned was cause and effect. His discussion was inadequate and marked by the duality found in his consideration of other ideas. We observe the order and connection of our ideas and the coming into existence of things and qualities. In pointing this out Locke was on strictly empirical grounds. When, however, he defined cause as “that which produces any simple or complex idea,” and “that which is produced, effect” (II.xxvi.1), he went beyond experience and rested his argument on reason. Locke undoubtedly saw the difficulties of his position. He was concerned, on the one hand, to show how we have the ideas of cause and effect from experience. On the other hand, he was not satisfied with a mere sequence theory. The difficulty arose, as it did with power and substance, because he was persuaded that there is a reality beyond the ideas manifest to us. It is a reality, however, about which he could say little in terms of his representationalism.

Identity and diversity. Under relation Locke also exam-ined identity and diversity, by which he meant the relation of a thing to itself, particularly with respect to different times and places. As was stated above, the identity of a plant, an animal, or a man consists in a participation in the same continued life. To this Locke added an examination of personal identity. He argued that personal identity is consciousness of being the same thinking self at different times and places.

Locke also discussed other relations, such as proportional, natural, instituted, and moral, which are not essential to the main argument of the Essay and which will, therefore, not be discussed here.

The remaining chapters of Book II of the Essay are devoted to “Clear and Obscure, Distinct and Confused Ideas,” “Real and Fantastical Ideas,” “Adequate and Inad-equate Ideas,” “True and False Ideas,” and “The Asso-ciation of Ideas.” All of them have merit in clarifying other parts of the Essay but add little that is new and not discussed elsewhere. Consequently, they will be passed over.

Language. At the end of Book II of the Essay Locke related that he had originally intended to pass on to a consideration of knowledge. He found, however, such a close connection between words and ideas, particularly between abstract ideas and general words, that he had first to examine the “nature, use, and signification” of language, since all knowledge consists of propositions. Book III, therefore, was incorporated into the Essay.

The merits of Book III are the subject of some controversy. Most scholars have dismissed it as unimportant and confused. Some, such as Aaron, see many merits in it despite its manifest inadequacies.

The primary functions of language are to communicate with our fellow men, to make signs for ourselves of internal conceptions, and to stand as marks for ideas. Language is most useful when general names stand for general ideas and operations of the mind. Since all except proper names are general, a consideration of what kinds of things words stand for is in order. “Words, in their primary or immediate signification, stand for nothing but the ideas in the mind of him that uses them” (III.ii.2). We suppose they stand for the same ideas in the minds of others. Words stand for things only indirectly. General words stand for general ideas, which become general by separation from other ideas and from particular circumstances. This process Locke called abstraction.

Definition. Definition by genus and differentia is merely a convenience by which we avoid enumerating various simple ideas for which the genus stands. (In this, Locke prepared the way for descriptive definition, which makes no pretense of defining the real essence of things.) It fol-lows that general or universal ideas are made by the understanding for its own use. Thus the essences of so-called species are nothing but abstract ideas. Locke asserted that every distinct abstract idea is a distinct essence. This must not be taken in a Platonic sense, for it is the mind itself that makes these abstract ideas. If essences are distin-guished into nominal and real, then with respect to simple ideas and modes there is no difference between nominal and real essence. In substances, they are decidedly different, in that the real essence of substance is unknowa-ble to us.

Names. Locke asserted that the names of simple ideas are not definable. One wonders, Is blue a general idea? If so, what is this blue as against that blue? What is separated out? What retained? Locke never examined these ques-tions, with the result that his conception of abstraction is vague and vacillating. Locke gave several distinct mean-ings to such terms as “general ideas” and “universal ideas,” shifting from one meaning to another and never clarifying them.

Complex ideas consisting of several simple ideas are definable and intelligible provided one has experience of the simple ideas that compose them. Without experience how can a blind man understand the definition of a rainbow?

Simple ideas are “perfectly taken from the existence of things and are not arbitrary at all” (III.iv.17). Ideas of substances refer to a pattern with some latitude, whereas ideas of mixed modes are absolutely arbitrary and refer to no real existence. They are not, however, made at random or without reason. It is the name that ties these ideas together, and each such idea is its own prototype.

Since names for substances stand for complex ideas perceived regularly to go together and supposed to belong to one thing, we necessarily come short of the real es-sences, if there are any. One may use the word “gold” to signify the coexistence of several ideas. One man may use the term to signify the complex idea of A and B and C. Another man of more experience may add D, or add D and leave out A. Thus, these essences are of our own making without being entirely arbitrary. In any case, the boundaries of the species of substances are drawn by men.

Connective words. In a brief chapter, “Of Particles,” Locke pointed out that we need words signifying the con-nections that the mind makes between ideas or proposi-tions. These show what connection, restriction, distinction, opposition, or emphasis is given to the parts of discourse. These words signify, not ideas, but an action of the mind. Again a difficulty arises. If “is” and “is not” stand for the mind’s act of affirming or denying, then either the mind directly apprehends its own actions in some way or we do have ideas of affirmation or denial. If we do have ideas of the mind’s acts, then these words ought to signify the ideas of these acts; if we do not have ideas which these words signify, then either we do not apprehend them or something besides ideas is the object of the mind when it thinks.

The remainder of Book III concerns Locke’s thoughts on the imperfection of words, the abuse of words, and his suggested remedies for these imperfections and abuses.

Knowledge. The first three books of the Essay are large-ly a preparation for the fourth. Many scholars see a fundamental cleavage between Book II and Book IV. Yet Locke saw no conflict between the two books, and whatever split existed in Locke’s thought runs throughout the Essay, as J. W. Yolton and others have pointed out. An effort can be made to reconcile Locke’s empiricism and his rationalism, his grounding of all ideas and knowledge in experience and his going beyond experience to the existence of things.

Many of Locke’s difficulties stem from his definition of “idea.” It is so broad that anything perceived or known must be an idea. But Locke showed, in Books I and II, that we get all our ideas from experience, not in order to claim that nothing exists except ideas, but to show that there is an alternative to the theory of innate ideas. For Locke, experience is initially a contact of bodies and subsequently a reflection of the mind. He never doubted the existence of an external physical world, the inner workings of which are unknown to us.

Sources of knowledge. There are two sources of knowl-edge-sensation and reflection. The ideas we have from reflection are in some important ways quite different from those we have from sensation. In Book II Locke asserted that the mind “turns its view inward upon itself and ob-serves its own actions about those ideas it has (and) takes from thence other ideas” ( The important point here is that in reflection the mind observes its own action. It is true that Locke spoke of modes of the simple ideas of reflection, such as remembering, discerning, reasoning, and judging. Nonetheless, if the mind does observe its own action, then something more than ideas are the object of the mind in reflection, or else ideas of reflection are somehow importantly different from the ideas of sensation. This point will show up in a consideration of Locke’s theory of knowledge.

Propositions. Locke defined knowledge as “the percep-tion of the connection and agreement, or disagreement and repugnancy, of any of our ideas” (IV.i.2). This agreement or disagreement is in respect to four types: identity and diversity, relation, coexistence or necessary connection, and real existence. Perceiving agreement or disagreement is quite different from just barely perceiving the ideas that are said to agree or disagree. Strictly speaking, this perception must be a distinct idea of either agreement or disagreement. Yet this was not Locke’s meaning. Where there is knowledge, there is judgment, since there can be no knowledge without a proposition, mental or verbal. Locke defined truth as “the joining or separating of signs, as the things signified by them do agree or disagree one with another” (IV.v.2). There are two sorts of propositions:

mental, “wherein the ideas in our understandings are, without the use of words, put together or separated by the mind perceiving or judging of their agreement or disagreement” (IV.v.5); and verbal, which stand for mental propo-sitions.

Judgments. In this view, ideas are the materials of knowledge, the terms of mental propositions. They are, insofar as they are given in sensation and reflection, the subject matter of reflection. If perception of agreement or disagreement in identity and diversity is the first act of the mind, then that act is a judgment. If we infallibly know, as soon as we have it in our minds, that the idea of white is identical with itself and different from that of red, and that the idea of round is identical with itself and different from that of square, we must distinguish between the bare hav-ing of these ideas and the knowledge of their identity and diversity. The knowledge of their identity and diversity is a judgment. It is reflective, and in it the mind perceives its own action or operation. There can be no distinction between the judgment and the idea of it. This is perhaps Locke’s meaning, which is unfortunately obscured by his broad use of the term “idea.” This perception of its own action is quite distinct from the abstract idea of the power of judgment. We may be uncertain as to how the mind makes judgments, what determines it to judge, or in what kind of a substance this power inheres, but we may be sure that in the actual making of a true judgment the mind perceives its own act. This position may be beset with difficulties, but it makes some sense out of Locke’s definition of knowledge.

Degrees of knowledge. Locke recognized two degrees of knowledge, in the strict sense of the term-intuition and demonstration. Of the two, intuition is more fundamental and certain. “The mind perceives the agreement or disagreement of two ideas immediately by themselves, without the intervention of any other” (IV.ii.l). Such knowl-edge is irresistible and leaves no room for hesitation, doubt, or examination. Upon it depends all the certainty and evidence of all our knowledge. Here, clearly, what the mind perceives is not any third idea, but its own act. In demonstration the mind perceives agreement or disagreement, not immediately, but through other mediating ideas. Each step in demonstration rests upon an intuition. This kind of knowledge is most evident in, but is not limited to, mathematics.

A third degree of knowledge is “employed about the particular existence of finite beings without us, which going beyond bare probability and yet not reaching per-fectly to either of the foregoing degrees of certainty, passes under the name of knowledge” (IV.ii.14). Locke called this sensitive knowledge. Fully aware of the dialectical difficulty entailed in this position, he grounded his reply to critics on common sense. The differences between dreaming and waking, imagining and sensing, are strong enough to justify this conviction. Hunger and thirst should bring a skeptic to his senses. For Locke, it was enough that com-mon sense supported him, for he always took sensory ideas to be signs or representations of something beyond them-selves.

Limits of knowledge. Locke asserted that knowledge extends no farther than our ideas and, specifically, no further than the perception of the agreement or disagree-ment of our ideas. We cannot have knowledge of all the relations of our ideas or rational knowledge of the necessary relations between many of our ideas. Sensitive knowledge goes only as far as the existence of things, not to their real essence, or reality. Two examples were given. In the first, Locke argued that though we have the ideas of circle, square, and equality, we may never find a circle equal to a square and know them to be equal. In the second, he observed that we have ideas of matter and thinking but may never know whether mere material being thinks. This has been discussed earlier.

In his controversy with Stillingfleet, Locke never aban-doned this latter thesis. And throughout this section (IV.iii) Locke showed that many relations of coexistence give us no certainty that they will or must continue to be so. He seemed persuaded that the continued discovery of new knowledge suggests that there are vast horizons of reality that we may advance upon but can never reach. With respect to the relations between abstract ideas we may hope to advance very far, as in mathematics. To this he added the belief that a demonstrable science of moral-ity is possible. On the other hand, he held that we can have no certain knowledge of bodies or of unembodied spirits.

Knowledge of existents. Locke argued that though our knowledge terminates in our ideas, our knowledge is real. “Simple ideas are not fictions of our fancies, but the natural and regular productions of things without us, really operating upon us; and so carry with them all the conform-ity which is intended; or which our state requires” (IV.iv.4). On the other hand, he argued: “All our complex ideas, except those of substances, being archetypes of the mind’s own making, not intended to be copies of anything, nor referred to the existence of anything, as to their originals, cannot want any conformity necessary to real knowl-edge” (IV.iv.5).

Universal propositions, the truth of which may be known with certainty, are not concerned directly with existence. Nonetheless, Locke argued that we have intuitive knowl-edge of our own existence. Here the argument is much the same as Descartes’s, and it is valid only if we accept the view that the mind in reflection perceives its own acts. This knowledge of our own existence has the highest degree of certainty, according to Locke.

We have a demonstrable knowledge of God’s existence, Locke held. He used a form of the Cosmological Argu-ment: starting with the certainty of his own existence, he argued to the necessary existence of a being adequate to produce all the effects manifest in experience. The argument assumed the reality of cause, the necessity of order, and the intelligibility of existence.

Of the existence of other things, as has been shown, we have sensitive knowledge. Locke felt the inconsistency of his position on this matter, yet accepted what he believed common sense required. We know of the coexistence of certain qualities and powers, and reason and sense require that they proceed from something outside themselves. Throughout these arguments about existence Locke went beyond his own first definition of knowledge.

Probability. The remaining portions of the Essay are concerned with probability, degrees of assent, reason and faith, enthusiasm, error, and the division of the sciences. Though Locke’s treatment of probability is inadequate, he recognized its importance. The grounds of probability lie in the apparent conformity of propositions with our experience and the testimony of others. Practical experience shows us that our knowledge is slight, and action requires that we proceed in our affairs with something less than certainty.

Faith was, for Locke, the acceptance of revelation. It must be sharply distinguished from reason, which is “the discovery of the certainty or probability of such proposi-tions or truths, which the mind arrives at by deduction made from such ideas which it has got by the use of its natural faculties, viz, by sensation or reflection” (IV.xviii.2). Though reason is not able to discover the truth of revelation, nevertheless, something claimed to be revelation cannot be accepted against the clear evidence of the understanding. Thus, enthusiasm sets reason aside and substitutes for it bare fancies born of conceit and blind impulse.

Error. Error cannot lie in intuition. Locke found four sources of error: the want of proofs, inability to use them, unwillingness to use them, and wrong measures of proba-bility. Locke concluded the Essay with a brief division of science, or human knowledge, into three classes-natural philosophy, or phyike, practical action and ethics, or praktike, and semieotike, or the doctrine of signs.

Influence of the “Essay.” Many minds of the seventeenth century contributed to the overthrow of the School philosophies and the development of the new sciences and philosophies. Descartes and Locke between them, however, set the tone and direction for what was to follow. Certainly Locke was the most prominent figure in the early eighteenth century, the indispensable precursor of Berke-ley and Hume as well as a fountainhead for the French Encyclopedists. If it is said that the two strains of Car-tesian rationalism and Lockian empiricism met in Kant, it can be added that Hume built on Locke’s foundation and Kant formalized much that was first a vague groping in Locke. Though Locke was not a wholly satisfactory thinker, his influence on thought in England and America has never completely abated, and even now there appears to he a revived interest in the Essay.


Locke’s earliest known political writings were the Es-says on the Law of Nature, written in Latin between 1660 and 1664 but not known until the Lovelace Collection was examined in 1946. They were first published in 1954 with a translation by W. von Leyden. Though much in these essays appears in the Essay Concerning Human Under-standing and the Two Treatises, there remain many points at which the early essays are in conflict with parts of both later works. This fact and the bother of translating them may have deterred Locke from publishing them, despite the urging of Tyrrell. Since von Leyden can find no evi-dence of direct influence of these essays on anyone other than Tyrrell and Gabriel Towerson, the student of Locke is referred to von Leyden’s publication for additional information.

The “Two Treatises.” The Two Treatises of Government appeared anonymously in 1690, written, it is said, to justify the revolution of 1688, or, according to the preface, “to establish the Throne of Our Great Restorer, our present King William; to make good his Title, in the Consent of the People.” Locke acknowledged his authorship only in a codicil in his will listing his anonymous works and giving to the Bodleian Library a corrected copy of the Two Treatises. He never felt that any of the editions printed during his lifetime had satisfactorily rendered his work. Only in 1960 did Peter Laslett publish a critical edition based on the Coste master copy of the Two Treatises.

The first treatise. It has long been suspected that the first treatise was written in 1683 and that the second trea-tise was written in 1689. Laslett has presented much evi-dence to show that the second treatise was the earlier work, written between 1679 and 1681. If his thesis is cor-rect, it was a revolutionary document, whose purpose was not primarily to philosophize but to furnish a theoretical foundation for the political aims and maneuvers of Shaftesbury and his followers in their struggle with Charles II. Only further scholarly probing will resolve this question.

In his preface, Locke stated that the greater part of the original work had been lost. He was satisfied that what remained was sufficient, since he had neither the time nor the inclination to rewrite the missing sections. The evidence is clear that it was portions of the first treatise that were lost.

The first treatise is a sarcastic and harsh criticism of Sir Robert Filmer’s Patriarcha, which argued for the divine right of kings. Locke’s treatise is more of historical than philosophical importance. It argued that Adam was not, as Filmer claimed, divinely appointed monarch of the world and all his descendants. Neither was the power of absolute monarchy inherited from Adam. Adam had no absolute rights over Eve or over his children. Parents have au-thority over children who are dependent upon them and who must learn obedience as well as many other things for life. The function of the parent is to protect the child and to help him mature. When the child comes to maturity, parental authority ends. In any case, the relation of parent and child is not the same as that of sovereign and subject. Were Filmer right, one would have to conclude that every man is born a slave, a notion that was utterly repugnant to Locke. Even if Filmer were correct, it would be impossi-ble to show that existing rulers, especially the English kings, possess legitimate claims to their sovereignty by tracing it back to lawful descent from Adam.

The second treatise. Locke began the second treatise with the proposition that all men are originally in a state of nature, “a state of perfect freedom to order their actions, and dispose of their possessions, and persons as they think fit, within the bounds of the Law of Nature, without asking leave, or depending upon the Will of any other man (II.ii.4). Although Locke sometimes wrote as if the state of nature were some period in history, it must be taken large-ly as a philosophical fiction, an assumption made to show the nature and foundation of political power, a fiction at least as old as Plato’s treatment of the Prometheus myth in the Protagoras. It is a state of equality but not of unbounded license. Being rational and being a creature bound by God, man must be governed by the law of nature.

Natural law. Though the concept of the law of nature is as old as antiquity, it flourished in the seventeenth century in the minds of a considerable number of ethical and po-litical thinkers. In general it supposed that man by the use of reason could know in the main the fundamental principles of morality, which he otherwise knew through Chris-tian revelation. Locke was extremely vague about the law of nature, but in his Essays on the Law of Nature he held that that law rests ultimately on God’s will. Reason discov-ers it. It is not innate. When, however, Locke spoke of it as “writ in the hearts of all mankind,” he suggested some kind of innateness. There are obvious difficulties here, for sense and reason may fail men, even though the law of nature is binding on all. Moreover, the various exponents of the law of nature differ on what it consists of, except that it presupposes the brotherhood of man and human benev-olence.

State of nature. In a state of nature, according to Locke, all men are bound to preserve peace, preserve mankind, and refrain from hurt to one another. The execution of the law of nature is the responsibility of each individual. If any man violates this law, he thereby puts himself in a state of war with the others, who may then punish the offender. The power that one man may hold over another is neither absolute nor arbitrary and must be restrained by proportion. The state of nature was for Locke a society of men, as distinct from a state of government, or a political society.

Social contract. There are certain inconveniences in a state of nature, such as men’s partiality and the inclination on the part of some men to violate the rights of others. The remedy for this is civil government, wherein men by com-mon consent form a social contract and create a single body politic. This contract is not between ruler and ruled, but between equally free men. The aim of the contract is to preserve the lives, freedom, and property of all, as they belong to each under natural law. Whoever, therefore, attempts to gain absolute power over another puts himself at war with the other. This holds in the political state as well as the state of nature. When a ruler becomes a tyrant, he puts himself in a state of war with the people, who then, if no redress be found, may make an appeal to heaven, that is, may revolt. This power is but an extension of the right of each to punish an aggressor in the state of nature. Unlike Hobbes, Locke was persuaded that men are capable of judging whether they are cruelly subjected and unjustly treated. Since one reason for men entering into the social contract is to avoid a state of war, the contract is broken when the sovereign puts himself into a state of war with the people by becoming a tyrant.

Slavery. Curiously, Locke justified slavery on the grounds that those who became slaves were originally in a state of wrongful war with those who conquered them and, being captive, forfeited their freedom. Apart from being bad history, this argument ignores the rights of the children of slaves. Locke’s inconsistency here may mercifully be passed over.

Property. Property was an idea which Locke used in both a broad and a narrow sense. Men have a right to self-preservation and therefore to such things as they need for their subsistence. Each man possesses himself absolutely, and therefore that with which he mixes his labor becomes his property. “God has given the earth to man-kind in common.” No man has original, exclusive rights to the fruits and beasts of the earth. Nevertheless, man must have some means with which to appropriate them. This consists of the labor of his body and the work of his hand. By labor, man removes things from a state of nature and makes them his property. Without labor, the earth and things in general have but little value. However, only so much as a man improves and can use belongs to him, nor may a man deprive another of the means of self-preservation by overextending his reach for property.

Though the right to property is grounded in nature, it is not secured therein. It is one of the primary ends of the state to preserve the rights of property, as well as to make laws governing the use, distribution, and transference of property. In communities or countries under government, there are fixed boundaries to the common territory, and there is land and property held in common which no one may appropriate to himself and to which those not mem-bers of the community have no right at all. Money, being something which does not spoil, came into use by mutual consent, serving as a useful means of exchange. At the same time it made possible the accumulation of wealth greater than warranted by need or use.

Political society. Having established several rights and duties belonging to men by nature and having shown certain inconveniences and disadvantages of the state of nature, Locke turned to political society. The first society consists of the family, whose aims are not initially or primarily those of political society, but which may be in-cluded under political society.

In political society “any number of men are so united into one Society, as to quit everyone his Executive power of the law of nature, and to resign it to the public” (II.vii.89). The legislative and executive powers are “a right of making laws with penalties of Death, and consequently all less Penalties, for the regulating and preserving of property, and of employing the force of the community, in the exe-cution of such laws, and in the defense of the common-wealth from foreign injury, and all this only for the public good” (II.i.3). By the social contract men give up, not all their rights, but only the legislative and executive right they originally had under the law of nature. This transfer-ence of power is always subordinate to the proper and true ends of the commonwealth, which are “the mutual preservation of their lives, liberties and estates.”

Each man must voluntarily consent to the compact either explicitly or implicitly. An individual who at age of discretion remains a member of the community tacitly consents to the compact.

Since the compact is made between the members of the community, sovereignty ultimately remains with the people. The sovereign, in the form of a legislative body, and executive, or both, is the agent and executor of the sover-eignty of the people. The community can act only by the rule of the majority, and everyone is bound by it, because an agreement of unanimity is virtually impossible. It is the people who establish the legislative, executive, and judiciary powers. Thus, an absolute monarch is incompatible with civil society.

Locke’s theories so far are compatible with either mon-archy, oligarchy, or democracy so long as it is recognized that ultimate sovereignty lies with the people. He believed that a constitutional monarchy with executive power, in-cluding the judiciary, in the hands of the monarch, and legislative powers in a parliamentary assembly elected by the people was the most satisfactory form of government. The supreme power he held to be the legislative, for it makes the laws that the executive must carry out and enforce. Whenever the executive violates the trust that he holds, no obligation is owed him and he may be deposed. The legislature may also violate its trust, though Locke believed it less likely to do so. Whenever this occurs, the people have a right to dissolve it and establish a new government. For this reason a regularly elected legislative body is desirable.

Rebellion. Locke explicitly recognized, as the events during his lifetime had shown, that men may become tyrants to those whom they were bound to serve. It may be a king, an assembly, or a usurper that claims absolute power. In such cases the people have a right to rebellion if no other redress is possible. Locke was not unmindful of the fact that the executive needs latitude and prerogative so that he may govern, and that the legislative body must deliberate and make laws which they believe to be in the public good. The right to rebellion is warranted only in the most extreme conditions, where all other means fail. Locke did not believe that men would lightly avail themselves of this power, for men will suffer and endure much before they resort to rebellion.

In transferring to the government the right to make and execute law and make war and peace, men do not give up the natural light of reason, by which they judge good and evil, right and wrong, justice and injustice. In specific laws or executive decisions judgment must be allowed to the legislature and the executive. If, however, a long train of acts shows a tyrannical course, then men, judging that the sovereign has put himself into a state of war with them, may justly dethrone the tyrant. On the other hand, the legislative and executive power can never revert to the people unless there is a breach of trust.

The dissolution of government is not the dissolution of society. The aim of revolution is the establishment of a new government, not a return to a state of nature. The dissolution of a government may occur under many circum-stances, but foremost among them are when the arbitrary will of a single person or prince is set in place of the law; when the prince hinders the legislature from due and lawful assembly; when there is arbitrary change in elec-tions; when the people are delivered into subjection by a foreign power; and when the executive neglects and abandons his charge. In all such cases sovereignty reverts to the society, and the people have a right to act as the supreme power and continue the legislature in themselves, or erect a new form, or under the old form place sovereignty in new hands, whichever they think best. On the other hand, “the power that every individual gave the society, can never revert to the individuals again, as long as the society lasts” (II.xix.243).

As theory, Locke’s second treatise is full of inadequacies, but its magnificent sweep of ideas prepared the ground for popular and democratic government.


Locke’s thought on education and religion was not presented in strictly philosophical terms. It was, however, deeply rooted in the fundamental concepts of the Essay and the Two Treatises. His works in these areas display clearly the liberal bent of his mind as well as his love of freedom, tolerance, and truth. His attitude was pragmatic and based on considerable psychological insight into the motives, needs, passions, and follies of men. Some Thoughts Concerning Education, several letters on tolera-tion, and The Reasonableness of Christianity profoundly affected educational and religious thought in the eight-eenth century and after. Two of these works, Some Thoughts Concerning Education and the first Letter on Toleration, continue to be fresh and relevant.

Education. When Locke was in Holland, he wrote a number of letters to Edward Clark advising him on the education of his son, a young man of no particular distinction. Locke had in mind the education of a gentleman who would one day be a squire. In 1693 Locke modified these letters somewhat and published the contents as Some Thoughts Concerning Education in response to “so many, who profess themselves at a loss how to breed their chil-dren.” His thought was marked by a ready understanding of, and warm sympathy with, children. Three main thoughts dominate the work. First, the individual aptitudes, capacities, and idiosyncrasies of the child should govern learning, not arbitrary curricular or rote learning taught by the rod. Second, Locke placed the health of the body and the development of a sound character ahead of intellectual learning. In the third place, he saw that play, high spirits, and the “gamesome humor” natural to children should govern the business of learning wherever possible. Compulsory learning is irksome; where there is play in learning, there will be joy in it. Throughout he placed emphasis on good example, practice, and use rather than on precepts, rules, and punishment. The work was an implicit criticism of his own education at Westminster and Oxford, which he found unpleasant and largely useless.

Writing almost as a physician, Locke advised “plenty of open air, exercise, and sleep; plain diet, no wine or strong drink, and very little or no physic; not too warm and strait clothing; especially the head and feet kept cold, and the feet often used to cold water and exposed to wet.” The aim in all was to keep the body in strength and vigor, able to endure hardships.

Locke urged that early training must establish the au-thority of the parents so that good habits may be estab-lished. The prime purpose is the development of virtue, the principle of which is the power of denying ourselves the satisfaction of our desires. The child should be taught to submit to reason when young. Parents teach by their own example. They should avoid severe punishments and beatings as well as artificial rewards. Rules should be few when a child is young, but those few should be obeyed. Mild, firm, and rational approval or disapproval are most effective in curbing bad behavior. Children should be frequently in the company of their parents, who should in turn study the disposition of the child and endeavor to use the child’s natural desire for freedom and play to make learning as much like recreation as possible. High spirits should not be curbed, but turned to creative use. Curiosity too should be encouraged, and questions should be heard and fairly answered. Cruelty must always be discouraged and courageousness approved.

As the child grows, familiarity should be increased so that the parent has a friend in the mature child. Virtue, breeding, and a free liberal spirit as well as wisdom and truthfulness were the goals set by Locke in all his advice. Affection and friendship were for him both means and ends of good education.

Learning, though important, Locke put last. First, he would have the child learn to speak and read his own language well by example and practice, not by grammar. In the study of all languages, he would put off the study of grammar until they can be spoken well. He would begin the learning of a second modern language early. Reluctantly he would allow a gentleman’s son to learn Latin, but he did not recommend much time on Greek, Hebrew, Arabic, rhetoric, or logic, which constituted the curricula of the universities of his day. Rather, time should be given to the study of geography, arithmetic, astronomy, geometry, history, ethics, and civil law. Dancing he encouraged, and music as well, in moderation. He was less sympathetic to poetry. Remarkably, he urged that everyone learn at least one manual trade and make some study of accounting. Finally, travel was valuable if not done before one could profit by it.

If much of this is familiar and even trite, it must be remembered that Locke was among the first to formulate these ideas. His influence on educational thought and practice was enormous and is still very much with us in its fundamental outlook and method.

Religion. Locke saw some merits in all the competing claims of various religious groups. He also saw the de-structive force that was released when these claims sought exclusive public dominion at the expense of individual conscience. He looked in several directions at once. This tendency has earned for him the reputation of being timorous and compromising. Nonetheless, it is on this trait of mind that much of his great influence and reputation rests. For Locke, fidelity to the evidence at hand always out-weighed cleverness, consistency, and dialectic. It is the chief testimony to his claim that truth was always his aim, even when he might have won an easy victory by dogmatic consistency.

Locke’s writings on religion are voluminous. When he died he was working on extensive commentaries on the Epistles of St. Paul, as well as a draft of a fourth Letter on Toleration. Earlier he had written and published three letters on toleration, The Reasonableness of Christianity (1695), and two Vindications (1695 and 1697) of the latter work. Moreover, Locke’s three letters to Stillingfleet, the bishop of Worcester, are concerned with religious questions as well as epistemological ones.

Religious tolerance. Locke’s first Letter Concerning Toleration stated his position clearly, and he never deviated from it substantially. It was originally written in Latin as a letter to his Dutch friend Philip van Limborch. In 1689 it was published on the Continent in Latin, and in the same year a translation of it by William Popple appeared in English.

Locke was not the first to write in advocacy of religious toleration. His was, however, a powerful, direct, and passionate plea. It was linked with the Essay by its recog-nition of the limits of human knowledge and human fallibility, and with the Two Treatises by his deep commitment to individual rights and freedom.

Locke took toleration to be the chief characteristic mark of the true church, for religious belief is primarily a relation between each man and God. True religion regulates men’s lives according to virtue and piety, and without charity and love religion is false to itself. Those who per-secute others in the name of Christ abjure his teachings, seeking only outward conformity, not peace and holiness. Who can believe that in torture and execution the fanatic truly seeks the salvation of the soul of his victim? Moreover, the mind cannot be forced or belief compelled. All efforts to force or compel belief breed only hypocrisy and contempt of God. Persuasion is the only lever that can truly move the mind.

A church is “a voluntary society of men, joining them-selves together of their own accord in order to the public worshipping of God in such manner as they judge acceptable to Him, and effectual to the salvation of their souls.” It is sharply distinct from a state, or commonwealth. The state is concerned with the public good, protecting life, liberty, and property. It has no authority in matters of the spirit. “Whatever is lawful in the commonwealth cannot be prohibited by the magistrate in the church.”

It is to be doubted that any man or group of men possess the truth about the one true way to salvation. In the Scriptures we have all that may reasonably be claimed by Christians to be the word of God. The rest are the specula-tions and beliefs of men concerning articles of faith and forms of worship. Sincere and honest men differ in these matters, and only tolerance of these differences can bring about public peace and Christian charity. Jews, pagans, and Muslims are all equally confident in their religious faith. Mutual tolerance is essential where such diversity exists. This is most evident when we observe that it is the most powerful party that persecutes others in the name of religion. Yet in different countries and at different times power has lain in the hands of different religious groups. It is physical power, not true faith, which decides who is persecuted and who persecutes.

Throughout Locke’s argument the liberty of person and the liberty of conscience are decisive. He limited this liberty only by denying to religion the right to harm directly another person or group or to practice clearly im-moral rites. By a curious and probably prudential excep-tion, he denied tolerance to atheists, because promises, covenants, and oaths would not bind them, and to any church so constituted “that all those who enter into it do thereby ipso facto deliver themselves up to the protection and service of another prince.”

Despite these limitations, Locke’s letter moved subsequent generations to a greater spirit of tolerance in religious matters. It is still part of the liberal democratic ideal and transcends the time of its composition.

Faith and reason. The Reasonableness of Christianity and the Vindications are works more bound to Locke’s own time. Locke was probably neither a Socinian nor a deist, even though certain deists and Unitarians found comfort and inspiration in his work. He was a sincere Christian, who tried to diminish the flourishing schisms and sects by proposing a return to the Scriptures and an abandonment of the interminable theological disputes of his day. He accepted the divine inspiration of the Bible. Nevertheless, he held that even revelation must be tested by reason. In the New Testament, Christianity is rational and simple. The core of Christian faith lies in the belief in the fatherhood of God, the divinity of Christ the Messiah, the morality of charity, love, and divine mercy. Justification by faith means faith in Christ, whose essential revelation is that God is merciful and forgives the sinner who truly repents and strives to live a life of Christian morality. The Mosaic law, God’s mercy, and Christian morality are all consonant with human reason. Revelation discloses to man what unaided reason could not discover — the mysteries, the Virgin Birth, the Resurrection, the divinity of Christ. But when disclosed, these do not violate the canons of reason. Here as elsewhere, Locke’s emphasis on reason was circumscribed, reason roust be followed where possible, but it does not carry us far enough by itself.

Locke’s influence was wide and deep. In political, reli-gious, educational, and philosophical thought he inspired the leading minds of England, France, America, and to some extent, Germany. He disposed of the exaggerated rationalism of Descartes and Spinoza; he laid the groundwork for a new empiricism and advanced the claims for experimentalism. Voltaire, Montesquieu, and the French Encyclopedists found in Locke the philosophical, political, educational, and moral basis that enabled them to prepare and advance the ideas which eventuated in the French Revolution. In America, his influence on Jonathan Ed-wards, Hamilton, and Jefferson was decisive. Locke’s zeal for truth as he saw it was stronger than his passion for dialectical and logical niceness, and this may account for the fact that his works prepared the ground for action as well as thought.

Works by Locke

Essays on the Law of Nature. Translated from the Latin and edited by W. von Leyden. Oxford, 1954. Also gives an account of the Lovelace Collection.

An Early Draft of Locke’s Essay (Draft A). R. I. Aaron and J. Gibb, eds. Oxford, 1936. Valuable as a study of the development of the Essay.

An Essay Concerning the Understanding, Knowledge, Opinion and Assent (Draft B), B. Rand, ed. Cambridge, Mass., 1931. Valua-ble, but superseded by manuscript in Bodlejan Library.

Epistola de Tolerantia. Gouda, 1689. Translated by William Popple as A Letter Concerning Toleration. London, 1689. Several defenses appeared in the 1690s and fragments of a fourth in 1706.

An Essay Concerning Human Understanding. London, 1690; 2d ed. with large additions, London, 1694; 3d ed., London, 1695; 4th ed., with large additions. London, 1700; 5th ed., with many large additions, London, 1706. Best modern edition, from which all quotes in this article are taken, is a reprint of the fifth edition, J. W. Yolton, ed., 2 vols. New York and London, 1961.

Two Treatises of Government. London, 1690. The critical and collated edition of Locke’s corrected copy by Peter Laslett (Cam-bridge, 1960) surpasses all previous editions.

Some Considerations of the Consequences of the Lowering of Interest and the Raising of the Value of Money. London, 1692. Two additional papers on money appeared in 1695.

Some Thoughts Concerning Education. London, 1693.

The Reasonableness of Christianity. London, 1695. Defenses of this work were published in 1695 and 1697.

A Letter to the Right Rev. Edward Ld. Bishop of Worcester, concerning Some Passages relating to Mr. Locke’s Essay of Hu-mane Understanding. London, 1697. Two further letters appeared, in 1697 and 1699.

A Paraphrase and Notes on the Epistles of St. Paul to the Gala-tians [etc.]. London, 1705.

Posthumous Works of Mr. John Locke. 6 vols. London. 1706.

The Remains of John Locke, E. Curl, ed. London, 1714.

Works of John Locke, 3 vols. London, 1714; 10th ed., 10 vols., London. 1801.

The Correspondence of John Locke and Edward Clarke, B. Rand, ed. Oxford. 1927.

For the remainder of Locke’s published and unpublished pa-pers, consult the works listed below by Aaron, Christopherson, von Leyden. Long, Ollion. and Yolton. See von Leyden and Long particularly for the Lovelace Collection.

Works on Locke


Bourne, H. R. Fox, Life of John Locke, 2 vols. London, 1876. Excellent, but inadequate since Lovelace Collection became available.

Cranston, Maurice, John Locke, a Biography. London, 1957. A thorough study of the life of Locke, using all materials available at present.

King, Lord Peter. The Life and Letters of John Locke. London, 1829. Not good, but contains original material.


Aaron, R. I., “Locke’s Theory of Universals.” PAS, Vol. 33 (1932! 1933). Useful and enlightening.

Aaron, R. I., John Locke. Oxford, 1937; rev. ed., Oxford, 1955. Best general commentary.

Adamson. S. W., The Educational Writings of John Locke. Cam-bridge, 1922.

Bastide, C., John Locke, ses theories politiques et leur influence en Angleterre.

Paris, 1906. Still valuable work on Locke’s political philosophy.

Christopherson, H. 0., A Bibliographical Introduction to the Study of John Locke. Oslo, 1930. Incomplete.

Clapp, J. G., Locke’s Conception of the Mind. New York, 1937. Cranston.

Maurice. “Men and Ideas; John Locke.” Encounter, Vol. 7 (1956), 46-54.

Czajkowski, C. J., The Theory of Private Property in Locke’s Political Philosophy. Notre Dame, Ind., 1941. Useful on the labor theory of value.

DeMarchi, E., “Locke’s Atlantis.” Political Studies, Vol. 3 (1955), 164-165.

Gibson, James. Locke’s Theory of Knowledge. Cambridge, 1917. Emphasizes Locke’s rationalism.

Gibson, James, John Locke. British Academy, Henrsette Hertz Lecture. 1933.

Gierke, Otto von, Naturrecht und deutsches Recht. Translated and edited by Ernest Barker as Natural Law and the Theory of Society, 2 vols. Cambridge, 1934. A major study.

Gough, J. W., John Locke’s Political Philosophy. Eight Studies. Oxford, 1950. Important.

Jackson, Reginald, “Locke’s Distinction Between Primary and Secondary Qualities.” Mind, Vol. 38 (1929), 56-76.

Jackson, Reginald, “Locke’s Version of the Doctrine of Repre-sentative Perception.” Mind, Vol. 39(1930), 1-25.

James, D. G., The Life of Reason. Hobbes, Locke, Bolingbroke. London, 1949.

Krakowski, E., Les Sources medievales de Ia philosophie de Locke. Paris, 1915. One of the few studies of influences on Locke.

Lamprecht, S. P., The Moral and Political Philosophy of John Locke. New York, 1918.

Laslett, Peter, “The English Revolution and Locke’s Two Trea-tises of Govemment.” Cambridge Historical Journal, Vol. 12 (1956). Interesting and controversial.

Leibniz, G. W., Nouveaux Essais sur lentendement humain. Leipzig and Amsterdam, 1765. Translated by A. G. Langley as New Essays concerning Human Understanding. New York and London, 1896. An important critique of Locke by a contemporary.

Leyden, W. von, “John Locke and Natural Law.” Philosophy, Vol. 31(1956). A useful examination.

Long, P., A Summary Catalogue of the Lovelace Collection of Papers of John Locke in the Bodleian Library. Oxford, 1959.

O’Connor, D. j., John Locke. Harmondsworth, England, 1952.

Ollion, H., Notes sur Ia correspondance de John Locke. Paris, 1908.

Polin, B., La Politique de John Locke. Paris, 1960. Interesting contrast to Laslett.

Pollock, Sir Frederick, “Locke’s Theory of the State,” in his Essoys in the Law. London, 1922. Ch. 3.

Ryle, Gilbert, Locke on the Human Understanding. Oxford, 1933.

Smith, N. K., John Locke. Manchester, England, 1933. Ware, C. S., “The Influence of Descartes on John Locke.” Revue internationale de philosophie (1950), 210-230.

Webb, T. E., The lntellectualism of Locke. An Essay. Dublin, 1857. Presents Locke as a precursor to Kant.

Yolton, J. W., “Locke’s Unpublished Marginal Replies to John Sergeant.” Journal of the History of Ideas, Vol. 12 (1951), 528-559.

Yolton, J. W., “Locke and the Seventeenth-Century Logic of Ideas.” Journal of the History of Ideas, Vol. 16 (1955), 431-452.

Yolton, J. W., Locke and the Way of Ideas. Oxford, 1956. A careful study.

Yolton, J. W., “Locke on the Law of Nature.” Philosophical Review, Vol. 67 (1958), 477-498.


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