The Ascendancy of the Essay

The Essay has long been recognized as one of the great works of English literature of the seventeenth century, and one of the epoch-making works in the history of philosophy. It has been one of the most repeatedly reprinted, widely disseminated and read, and profoundly influential books of the past three centuries, since its initial publication in December 1689. In particular, it has been and continues to be actively studied by philosophers and students of philosophy the world over; the reasons for this are naturally complex, but two focal points may be singled out.

(I) The Essay gained for itself a unique standing as the most thorough and plausible formulation of empiricism—a viewpoint that it caused to become an enduring powerful force. Philosophical terms ending in 'ism', e.g. 'empiricism', and their cognates and various other class or type terms are dangerous to apply because they may, and commonly do, conceal historical differences and even divergences; it may therefore be misleading to use them without definite clarification, and it may be impossible to give a satisfactory short account of the meaning of such a term because imprecision may be the price of brief comprehensiveness. The ordinary needs and habits of communication, however, override these difficulties to a great extent. The empiricism of Hobbes (1588-1679), Locke (1632-1704), and Hume (1711-76) should be seen as a compound of several doctrines, not all of them exclusively epistemological. Among them are, as a first approximation: that our natural powers operate in a social and physical environment that we seek to adapt ourselves to, and that the variable functioning of these powers in that environment is the agency by which we get and retain all our ideas, knowledge, and habits of mind; that our capacities of conscious sense-experience and of feeling pleasure or discomfort are primary natural powers; that the abuse of language, especially in scholastic systems and indulgent speculative hypotheses, is a troublesome source of errors and of obstacles to intellectual improvement and moral and social stability; that religious fervour is contemptible and sectarian strife is deplorable; and that although science, which proceeds by reasoning about propositions whose terms represent existent ideas or realities, deserves our respect, its scope for attaining conclusive success is extremely limited at best. A marked difference between Hume's empiricism and Hobbes's and Locke's is his low estimation of the power of reason; Hume's assertion that reason 'can never pretend to any other office than to serve and obey' the passions would have been abhorrent to Hobbes and Locke.

The Essay presents, for the first time, a systematic, detailed, reasoned, and wide-ranging philosophy of mind and cognition whose thrust, so far as it is in line with the future rather than the past, is empiricist. It must be acknowledged that it was Hobbes among British philosophers—concurrently with the Frenchman Gassendi (1592-1655)—who first produced in the modern era, especially in his Leviathan and De Corpore, a philosophy of mind and cognition that built on empiricist principles. A characteristic declaration of Hobbes's empiricism (and nominalism) is:

No Discourse whatsoever, can End in absolute knowledge of Fact, past, or to come. For, as for the knowledge of Fact, it is originally, Sense; and ever after, Memory. And for the knowledge of Con-sequence, which I have said before is called Science, it is not Absolute, but Conditionall. No man can know by Discourse, that this, or that, is, has been, or will be; which is to know absolutely: but onely, that if This be, That is; if This has been, That has been; if This shall be, That shall be: which is to know conditionally; and that not the consequence of one thing to another; but of one name of a thing, to another name of the same thing.

(Leviathan, I. vii).

Nevertheless, that Hobbes was a forerunner does not detract from Locke's achievement and role. Hobbes did not manage to write a book that could begin to match the quickly won and lasting popularity of Locke's major work. His masterpiece, Leviathan, differs from the Essay in not being chiefly concerned with questions in the philosophy of mind and cognition, and it is these that have been largely dominant since the sixteenth century. Hobbes did not undertake a systematic tracing of our ideas to their empirical origins; this was pioneered by Locke, who deployed in the process an original concept of experience divided into external ('sensation') and internal ('reflection'). Also, in contrast with Locke's emphatic dualism of mind and body, his moderate theism, and his ultimately libertarian account of action, Hobbes's reduction of everything to bodies and motions, his suspected atheism, and his strict determinism were—along with his extreme egoism in ethics—repugnant to his contemporaries and to the next century and beyond; and his theory of matter was soon overtaken by that of Boyle (1627-91), from which Locke's derives. An additional, different sort of reason may be conjectured: Hobbes's name in his own period and in the next century did not, unlike that of the author of the Essay, resound with opposition to authoritarianism, with the vindication of toleration (i.e. religious freedom), and with other liberal values, with which the generality of advancing philosophers and educationists associated themselves.

(2) The Essay is rich in philosophical matter; this makes it a much sought-after quarry—both a source and a target. As a glance through the Contents or the book itself reveals, it grapples with fundamental questions in the philosophy of mind and cognition, and with some in the philosophy of language, the philosophy of logic, the philosophy of religion, and moral philosophy; and it touches on numerous other topics. The book is written in a broadly intelligible style, and the gist of its teachings and the outlines of its arguments are tolerably clear. So what it says about, for example, innateness, experience, sense-perception, self-knowledge, qualities, memory, space, time, number, infinity, freedom and necessity, universals, substance, causality, personal identity, truth and falsity, meaning, knowledge, probability, belief, and the role of logical principles, is often found a convenient starting-point for further consideration by practising philosophers. But to the critically minded, even if they find the tenor of his work attractive, Locke's statements, assumptions, and arguments, amidst the rambling rose (and rows) of the Essay, are a continual provocation; this comes about especially through his simplicities and conflations, the ambiguities of key terms and hence of key assertions, and inner tensions and clashes in his thought: these sometimes make him resemble Bunyan's Mr. Facing-bothways, Mr. Two-tongues, and the 'Water-man, looking one way, and Rowing another'. On the other hand, the divisions and oppositions in his thought (e.g. between his perceptual idealism and realism, his naturalism and supernaturalism, and his factual claim that 'Number applies it self to … every thing' and his nominalist claim that 'Names [are] necessary to Numbers') may well have been creative: without them, he might not have been driven to pursue his problems as persistently and devotedly as he did in preparing the Essay over many years—and then, after its publication, recurrently touching it up and writing additions for it—in order to resolve them with full explicitness and coherence. Of course, he did not succeed. But has any other philosopher succeeded better, or been of more widespread service to his fellows?

Locke's Life and Works

Locke's biography, besides its intrinsic interest, affords essential knowledge of the context in which the Essay was produced, and of its place among his works.

John Locke (29 August 1632-28 October 1704) was the son of John Locke senior (1606-61), an attorney and small land-owner, and Agnes Locke (née Keene) (1597-1654). He was born and brought up in a district of Somerset that was within ten miles of Bristol. One permanently formative part of his upbringing was his induction into his parents' determined Protestant faith; this led him in his manhood to be contemptuous and distrustful of religious enthusiasts, Catholics, and atheists. From the age of fourteen he was educated at Westminster School, which he later described as being a 'very severe schoole' because of the flogging practices there. (In his Some Thoughts Concerning Education he counselled strongly against the punishment of children as a means of correcting or guiding them; kind firmness should suffice.) From Westminster, where he received a thorough grounding in Latin and Greek, Locke went in 1652 to Christ Church, Oxford, where, after following the usual Arts course (in Classical studies, grammar, rhetoric, logic, geometry, and moral philosophy) with limited interest and with distaste for the disputatious exercises, he graduated B.A. in 1656. He shortly afterwards became a senior Student of his college and retained this status, with rooms and emoluments, until Charles II (1630-85) personally required his expulsion in 1684, in the wake of Shaftesbury's final fall. It was perhaps in the late 1650s that Locke first read, and was refreshed by, Descartes (1596-1650). About this time or a little later he began to take an interest in physical science, and then in medicine where he became a close associate of Sydenham (1624-89), the distinguished physician with notable empirical learnings. He was acquainted with Boyle, the chemist and physicist (whose liberal views on toleration Locke found persuasive) and probably with other originators of the budding Royal Society, of which he became a Fellow in 1668. He lectured on Greek and rhetoric and performed supervisory duties for his college until 1665, when he left the confines of the academic world, henceforth to mix at home and abroad with persons of rank, affairs, and fortune, and with distinguished virtuosi, physicians, and scholars.

In the winter of 1665-6 he was abroad for the first time, as secretary to Charles II's ambassador to the Elector of Brandenburg at Cleves, where, as he wrote to Boyle, the Calvinists, Lutherans, Catholics, and Anabaptists 'quietly permit one another to choose their way to heaven'. He returned home, his future course still uncertain. He desired to get exemption from the usual obligation of a Student to take holy orders, and to be allowed to remain a layman by qualifying as a physician with a higher degree, and so, without waiting to fulfil the conditions for graduating M.B. first (he obtained this degree in 1675), he made a bid for the degree of Doctor of Medicine; after a failure, he gained his exemption in 1667, but not the degree.

A chance encounter had occurred in 1666 that proved to be the decisive turning-point in Locke's life: he met Lord Ashley (1621-83; created Earl of Shaftesbury, 1672), at that time Chancellor of the Exchequer, who used his influence to get Locke granted the latter's desired exemption from holy orders. Ashley soon invited Locke to take up residence at his London house, where Locke lived, from 1667 to 1675, as confidant and medical adviser. Locke was responsible in 1668 for a life-saving surgical operation on Ashley, who remained duly grateful. He subsequently became Secretary to the Lords Proprietors of Carolina (of whom Ashley was the most important) and to the Council of Trade and Plantations (of which Ashley was the President), and, during his patron's Lord Chancellorship his Secretary for Presentations. These private and public roles were congenial to him. This was the happy period when the Essay was initially engendered, shaped, and developed. Without Ashley, there would have been no Essay. Ashley's powerful personality, keen mind, and forward-looking outlook probably did much to strengthen and extend Locke's maturing liberalism, not least by adding an economic dimension to it.

In November 1673 Shaftesbury (as Ashley had become) was dismissed by the King from the Lord Chancellorship; his other offices were then terminated, and the Council of Trade and Plantations was abolished. Locke must have been dismayed by all this; he was a man who (in Sydenham's description) had more than 'naturall tenderness and delicacy of sence', i.e. was hypersensitive. The upset and Locke's resulting fear—those were harsh days of royal retribution—contributed to the return of his asthmatic cough, from which he often suffered till his death.

There was an introverted, valetudinarian component in Locke's nature—which may have aided his self-preservation. He was a careful, cautious man, possessed of a good sense of business and method. Almost until he died he kept, with minute exactness, running accounts of all monies he received, spent, lent, or owed. He shied away from drinking parties and other hectic forms of social life, and from emotionality, high spirits, the dramatic, and even the aesthetic. He never married, and remained, it seems, completely continent; but he liked the attentions of lady admirers. He had many loyal friends, and got on especially well with some of his friends' children. His preference was for undisturbing circumstances and friendly surroundings where he could be active and industrious while maintaining an independence, calmness, self-control, and deliberation in all things; but from time to time unruly events and people unfortunately intruded.

Locke's finances were much improved by an annuity to which Shaftesbury substantially contributed. With Shaftesbury's consent he went abroad, to France (where he had been for a few weeks' holiday in 1672); he stayed there, with bases first at Montpellier and then at Paris, from November 1675 till the end of April 1679, when he returned to England, as it happened promptly on Shaftesbury's resumption of public office. He occupied those years with travel, acting as a tutor-companion, diverse reading, translating (some of the Essais de morale of Pierre Nicole (1625-95)), social visits, and numerous scientific, medical, philosophical, and other intellectual interchanges; and with writing up his Journal that he commenced on his departure, filling it with records of books, medical and scientific notes, descriptions of his travels, money accounts, other memoranda, and a variety of philosophical sketches, many of them substantial and mostly on themes to be found in the Essay for which the sketches, after revision, were perhaps designed. It was during this period that he became a friend of the future Earl of Pembroke (1656-1733) to whom the Essay is dedicated. (Pembroke achieved a remarkable double: he is also the dedicatee of Berkeley's Principles of Human Knowledge (1710).)

When Locke returned from France in 1679, English politics were disturbed, and continued to be so for another ten years, by the consequences of the Catholicism of Charles II's younger brother James (1633-1701), the heir apparent. To many citizens—Locke among them—a papist King meant monarchical despotism, the forced conversion of the nation to a Catholic kingdom, its subservience to foreign powers, and persecution. A number of politicians, with Shaftesbury and his party, the Whigs, in the vanguard, wanted, even desperately, to get James's succession excluded by Act of Parliament. Charles, while an avowed Anglican, had shown that he was not without Catholic sympathies, and on his deathbed he entered the Church of Rome. Further, he saw that a victory for his opponents would affect his own powers. He stood by his brother. The Whigs lost that battle. Shaftesbury, in 1681, now in poor health, was committed to the Tower of London (where he had already spent a year in 1677-8) on a charge of high treason; he had a moment of triumph when he was acquitted by the grand jury, but, fearing revenge for the indignities he had inflicted on the King in recent years, he soon fled to Holland in November 1682 and died in Amsterdam a couple of months later. Locke, who, although he had not returned to Shaftesbury's employment in 1679, had actively continued his association with him, liked and admired him both as a statesman concerned with liberty and toleration and for his personal qualities. Shaftesbury's body was brought back to England for burial; Locke attended the funeral.

We have only sporadic pieces of Locke's philosophical writing during the years 1679-83, when perhaps his principal literary activity was harnessed to politics and toleration. This was interrupted in August 1683. By this time a number of Whigs—peers, publicists, and ordinary followers—had been arrested and Locke, as a known Shaftesburian, planned his removal to Holland (tolerant, and convenient for keeping in touch with friends in England), where he arrived on 7 September into a second exile that was to last longer than his first, French one. It was during his stay in Holland that his decades of reading, thinking, note-making, and drafting leaped towards momentous and manifold authorship. He further drafted and rewrote material for the Essay, getting this into final shape; he also made an abridgement of the book which, appearing in French translation in a scholarly periodical in 1688, at once brought international attention to the Essay. He wrote his Epistola de Tolerantia (Letter on Toleration), and possibly worked on the Two Treatises of Government. His Some Thoughts Concerning Education was mostly composed from letters of this period that he sent to his friend and agent Edward Clarke (c. 1650-1710) about the upbringing of the latter's son Edward.

Charles II died in 1685 and James became King, speedily arousing hostility and agitations because some steps and policies of his were markedly Catholic. William of Orange (1650-1702) and his wife Mary (1662-94), who were James's nephew and daughter, and Protestants, became joint King and Queen of England, after James had been compelled by events to withdraw to France in December 1688. William had landed in England in November 1688; Mary, like Locke, waited in Holland until all was settled, when they sailed, in February 1689, in the same yacht to Greenwich.

After his return to England Locke lodged in London, which he continued to visit fairly frequently until 1700 from an estate called Oates, near High Laver (about twenty-five miles from London) in Essex, where from Christmas 1690 he stayed for periods as a paying guest, and then from 1692 settled as a resident in the house of Sir Francis Masham, M.P. (1645-1722) and his second wife, Damaris (1659-1708), a daughter of the Cambridge Platonist, Ralph Cudworth (1617-88): it was probably Damaris who invited Locke to make his home at Oates, and it was she who looked after him in his last days.

Within a week of Locke's arrival in London in 1689 he was offered the post of English ambassador to the Elector of Brandenburg (the future King Frederick I of Prussia). But he resolved, after the dangers, discomforts, and interruptions of so many years, to remain in England; and he never left it again. He declined the King's offer on the grounds of 'that weak and broken constitution of my health which has soe long threatend my life', his inexperience in diplomatic business, and the disability from his being 'the soberest man in the Kingdom' who knew 'noe such rack in the world to draw out mens thoughts as a well managed Bottle'. The only occupation as a public servant he then accepted was as a Commissioner of Appeals in Excise; later he held the demanding and more important office of a Commissioner of the Board of Trade until 1700. From 1689 he took an active interest in parliamentary affairs and contributed significantly towards the liberation of printing and publishing from the constraints of the Licensing Act.

Locke's refusal of a diplomatic appointment had been motivated not merely by considerations of his health and convenience. He had plans as an author that he was determined to accomplish. He urgently wanted to see the Essay and the Two Treatises of Government properly in print; the manuscripts of these were in their almost final state. The completed manuscript of his Epistola de Tolerantia had been left behind for printing in the care of his closest Dutch friend van Limborch (1643-1712), a scholar and theologian belonging to the heterodox Remonstrant sect of Dutch Calvinists who believed (as Locke did) that the sovereignty of God is compatible with man's freedom and does not entail predestination; the book was published in Gouda in Spring 1689, and an English translation (by another hand) in London six months later. That Locke's first published book was on toleration and his next to appear, about mid November 1689 (only about a month before the Essay), was the Two Treatises, with its insistence that the authority of rulers is limited and conditioned by individuals' rights and the sake of 'the Publick Good', is symbolic of Locke's moral priorities, which are largely influential in the Essay too. He was already disposed towards the priority of the moral when a young man: his earliest surviving systematic writings, left unpublished, were on questions of toleration, political power, and natural law. He had, in one way or another, been working towards the Epistola for nearly thirty years, the Essay for nearly twenty years, and the Two Treatises for a decade; the results of all these prolonged efforts, made in days of light and shadow, suddenly emerged into public view in 1689, which was indeed Locke's annus mirabilis.

The Essay bore the author's name, as the already published abridgement had done; the other two books remained anonymous until after his death, when his acknowledgement of their authorship in his last will became known. Whether the anonymity of these and some of his other books was due solely to a wish to appear unegotistically concerned with principles or was in some degree motivated by self-protection against personal attacks by opponents is a matter of conjecture.

Although Locke was approaching sixty, his energy for writing books was far from waning. Two additional pieces on toleration soon followed (1690, 1692; these and other book dates below are those on the title-page of the first printing); three on monetary matters (1692, 1695, 1695); Some Thoughts Concerning Education (1693); and The Reasonableness of Christianity (1695), and two defences of it (1695, 1697), which represented Christianity, on the historical basis of scripture, in a latitudinarian spirit. Locke was certainly unorthodox; he was also devout.

The last years of the 1690s were taken up with a lot of work relating to the Essay again. Locke wrote three successive replies—the first two of moderate length, the third of 120,000 words—to criticisms of the Essay made by Edward Stillingfleet, Bishop of Worcester (1635-99). He had carefully revised the Essay for the second edition (1694), substantially altering one chapter (II. xxi) and adding another (II. xxvii); he now renewed this task for the fourth edition (1700), and added two more chapters (II. xxxiii and IV. xix). He actively supervised a French translation, and took some interest in the preparation of a Latin translation (1700, 1701, respectively).

Locke's last completed book was the studious Paraphrase and Notes on the Epistles of St. Paul; this was published posthumously (1705-7), as was a collection of other Posthumous Works (1706), of which the most substantial item was 'Of the Conduct of the Understanding', edited from an extensive and heavily amended manuscript which Locke had for some years been trying to finalize for incorporating as a very long additional chapter into the Essay.

Objectives of the Essay

During the seventeenth century educated opinion in England—to some extent paralleled on the Continent—drifted from an admiring preoccupation with the history, literature, and language of the ancient world, especially Rome, and from Christian theology and ritual, logical formality, scholastic thought, and authoritarianism, towards, in various degrees of proximity, a confidence in the superiority of modern novelties and modern powers, reasonable religion and secular values, personal expression and plain style, a critical appeal to reason and the rule of sensible evidence, and individualistic, egalitarian freedom of practice, thought, and judgement. The Essay had this distinction, that in it Locke was a firm spokesman for all these currents at once, in association with an elaborated philosophy of mind and cognition. His progressive predecessors and contemporaries, such as Gilbert (1540-1603), Bacon (1561-1626), Hobbes, Descartes, Spinoza (1632-77), and Bayle (1647-1706), favoured only some of them while opposing others, or did not connect them with a general philosophy suited to propelling them further. The propagation of these currents was a significant part of Locke's purpose in the book, whose prefatory Epistles immediately reveal his attitude in regard to several of them.

Thus, he upheld novelty and the independence of individual judgement by saying that 'The Imputation of Novelty, is a terrible charge amongst those, who judge of Men's Heads, as they do of their Perukes, by the Fashion; and can allow none to be right, but the received Doctrines', and that the quest of the Essay 'is the Entertainment of those, who let loose their own Thoughts, and follow them in writing'. He stressed the vital role of the search and application of experienced fact in the accumulation and testing of truth; it is 'Trial and Examination must give [Truth] price, and not any antick Fashion'. He returned to these themes repeatedly; and with striking rhetoric near the end of the book he launched attacks on both those who dictate opinions and those who submissively follow them, and derided the suffering of 'the learned Professor' whose 'Authority … [is] overturned by an upstart Novelist' ('Novelist' = 'innovator').

He also, influentially, complimented the attainments of the commonwealth of learning of his age, with its 'Master-Builders, whose mighty Designs, in advancing the Sciences, will leave lasting Monuments to the Admiration of Posterity', and blamed the 'learned but frivolous use of uncouth, affected, or unintelligible Terms, introduced into the Sciences' and 'Vague and insignificant Forms of Speech, and Abuse of Language, [which] have so long passed for Mysteries of Science' for the earlier lack of progress. These and other remarks of his soon, and have often since, struck readers as implying that the only profitable intellectual pathway to the knowledge of things is through observational, experimental, and mathematical methods, the only alternative being idle, verbal speculation. And on top of this Locke seemed to boost the branches of learning that use those methods, by describing in very modest terms his philosophical tasks, of analysing the understanding and the pathology and purgation of language, as if they were merely subservient to the smooth advancement of such knowledge. But his turns of phrase here were an ironic masking of his priority of concern with conduct over scientific inquisitiveness. Accordingly, a philosophical inquiry into the nature and grounds of certainty was required above all to determine the application and scope of certainty in the most important cases, namely in religion and ethics.

A passage in the Epistle to the Reader narrates the origin of Locke's engagement with his philosophical tasks: some friends of his at a meeting in his apartment found themselves in difficulties on all sides in the course of their discussion on a subject very remote from that of the understanding; whereupon—Locke now involving himself—'it came into my Thoughts, that we took a wrong course; and that, before we set our selves upon Enquiries of that Nature, it was necessary to examine our own Abilities, and see, what Objects our Understandings were, or were not fitted to deal with'. A partial hint of the subject of the discussion was provided in I. i. 6-7, where after postulating that 'Our Business here is not to know all things, but those which concern our Conduct' … a view he shared with Nicole, he went on to explain that 'This was that which gave the first Rise to this Essay concerning the Understanding. For I thought that the first Step towards satisfying several Enquiries, the Mind of Man was very apt to run into, was, to take a Survey of our own Understandings, examine our own Powers, and see to what Things they were adapted. Till that was done I suspected we began at the wrong end', this common mistake resulting in the multiplication of irresolvable disputes and in complete scepticism. This throws light on the programme he had just stated: it is 'my Purpose to enquire into the Original, Certainty, and Extent of humane Knowledge; together, with the Grounds and Degrees of Belief, Opinion, and Assent … It is therefore worth while, to search out the Bounds between Opinion and Knowledge; and examine by what Measures, in things, whereof we have no certain Knowledge, we ought to regulate our Assent, and moderate our Perswasions'.

He readily assumed, because of his presupposed identification of what is in the mind and what may be consciously perceived, that an adequate ophthalmology of the eye of the understanding can be discovered by a process of self-examination. But Locke did not regard this as being an a priori science that could be completed and made certain once and for all, as Kant (1724-1804) was later to do in respect of his articulation of reason in the first Critique. Locke conceded his fallibility, admitting (too much for Kantian and post-Kantian tastes) the limitations and imperfections of his subject—the natural philosophy of mind and cognition, and semantics.

Locke's friend James Tyrrell (1642-1718), whose interests and views regarding politics and toleration were closely similar to Locke's, was present at the original meeting in Locke's apartment; he annotated the passage on the history of the Essay in Epistle to Reader, and recorded in his copy that the discussion had been about 'the Principles of morality, and reveald Religion'. These were not neglected in the Essay; but Locke's version of those principles underlay his text much more than they were his main explicit topics. His direct treatment of those principles here was occasional, and clearer in what it denied than what it affirmed. The innateness of moral principles was controverted in I. iii; the thesis that moral science is capable of demonstration, as well as mathematics is, was adumbrated more than once, although never worked out, despite repeated requests by another friend, the Irishman William Molyneux (1656-98); and an account of moral conditions and relations was included in II. xx-xxi and xxviii. 4-16. These last passages supplied all that Locke wanted to state in the Essay about the norms of conduct. The source of the highest of these norms is the divine law, 'whether promulgated to [Men] by the light of Nature, or the voice of Revelation…. by comparing them to this Law, it is, that Men judge of the most considerable Moral Good or Evil of their Actions; that is, whether as Duties, or Sins, they are like to procure them happiness, or misery, from the hands of the ALMIGHTY'. Locke was brief about this supreme matter because he, in part rightly and in part to avoid spoiling his case by the inclusion of controversial details, presumed his readers' awareness of the content of the moral life entailed by his references to 'the light of Nature', i.e. reason, which is 'natural Revelation', and to supernatural revelation in the Bible.

Revealed religion was discussed in two chapters (IV. xviii, xix), in which he restricted it, obliquely, to the Christian scriptures by his distrust and contempt of other pretensions to revelation, and rationalistically emphasized that no supposed revealed proposition can contradict our knowledge or reason. There had been anticipations of this distrust, contempt, and rationalism earlier in the Restoration by, amongst others, Joseph Glanvill (1636-80) in his essays on 'The Usefulness of Real Philosophy to Religion', 'The Agreement of Reason and Religion', and 'Anti-fanatical Religion and Free Philosophy'; and prior to the Restoration by Hobbes (Leviathan, III. xxxii). Those attitudes and standards prefigured the militant deism and atheism of the eighteenth century, which adopted them against the Christian scriptures too. Locke renewed his inquiry into the principles of revealed religion in his Reasonableness of Christianity. In this, as is clear from its first paragraph, he advocated a historical empiricism, plainness of sense, and the rejection of systems of divinity with their 'learned, artificial, and forced senses' of expressions, in the understanding of the scriptures, which were for him, with his simple faith, designed by God 'for the instruction of the illiterate bulk of Mankind in the way to Salvation; and therefore generally and in necessary points to be understood in the plain direct meaning of the words and phrases, such as they may be supposed to have had in the mouths of the Speakers, who used them according to the Language of that Time and Country wherein they lived'. The considerations adduced here are analogous to or identical with fundamental grounds he utilized in the Essay. Locke did not labour to support them: they were what he built on and around.

Human Understanding

It has frequently happened to great philosophers that they have been in the grip of contrastive pairs of fundamental convictions, valuations, or orientations, and hence commonly that what they have constructed is itself riddled with inner clashes and tensions; thus Plato's conceptions of the soul as movement and life, and as allied to the Ideas which are unmoving and lifeless, were scarcely harmonious notions of reality, any more than were his conceptions that each Idea is a supreme reality and that the Ideas are sortally related in a hierarchical way; and underlying Kant's bifurcation of 'the starry heavens above and the moral law within' were his opposing principles about the regulated world of empirical appearances and the free world of spiritual values. Locke likewise was torn or driven in contrary directions. His committed antiscepticism was at odds with his chief epistemological stance, which was agnostic. His restriction of our proper business to knowledge of matters of conduct was, as perhaps he recognized and excused, curious in an author of a large epistemological book that was distinctly reticent, yet not agnostic, about our knowledge of such matters. His perceptual realism pulled against the idealism bound up with ways in which he persistently used the term 'idea' to stand for 'whatsoever is the Object of the Understanding when a Man thinks', and against his corpuscularian conception of the nature of material things, together with his doctrine of secondary versus primary qualities. His rationalistic canon that 'Reason must be our last Judge and Guide in every Thing' was not readily convergent with his empiricist or his Christian convictions.

These illustrations should be complemented by another observation. In his constructive efforts Locke had to reconcile with one another his repudiation of sophistical speculation and the abuse of language, his wish to be instructive, and his urbane concern that his philosophical output be fit and able to be 'brought into well-bred Company, and polite Conversation' ('polite' = 'civilized'). The latter consideration imparts a new twist to the cause of plain simplicity of utterance advocated a generation or two earlier by preachers and by spokesmen linked with the Royal Society, with the aims—which Locke also shared—of securely effecting moral or scientific improvement. One symptom of his not always successful struggle is that he entitled the book an 'Essay' which suggested a personal, informal, descriptive work catering widely for the ordinary educated reader; and yet within the text he sometimes called it a 'Treatise', which connoted a more ponderous, systematic, and learned book.

One of the consequences of Locke's determination to be informal in the Essay was that he did not make clear near the beginning what he meant by the 'human understanding', and it was not until he reached II. vi. 2, after numerous, apparently synonymous references to 'the Mind' and 'the Understanding', that he turned, in passing, to elucidate these terms and the relation between their designations. He distinguished, following tradition, between the 'two great and principal Actions of the Mind', which are perception or thinking, and volition. The understanding—the term corresponded to the Latin intellectus, 'intellect'—is the mind's faculty, power, or ability to think; volition is the mind's faculty, power, or ability to will. Locke showed, at II. xxi. that he was aware of some problems about the meaning and use of 'faculty'; but he did not dwell on them. The term 'the Mind' is usually applied in the Essay to represent only the understanding. Further, this intellectual faculty is not uniform, but is exercised in a variety of ways, among them contemplating, remembering, distinguishing, comparing, compounding, abstracting, reasoning, judging, knowing, and believing.

With a stab at Descartes's school, Locke excluded the passions, e.g. desire, love, hatred, and anger, from the faculty of volition. He described desire, feeling, and emotion as variants of pleasure or pain, which are states of the understanding. Not surprisingly in view of his medical interests, he assigned an important place in the life of the mind to the passions, especially to what he called uneasiness, 'All pain of the body of what sort soever, and disquiet of the mind'. It is uneasiness alone that determines the will; nevertheless, as Locke insisted in 'Of the Conduct of the Understanding' with Socratic intellectualism, the will 'never fails in its Obedience to the Dictates of the Understanding'. Hence a man's thoughts bear a responsible precedence in him as a cognitive and as an active agent. But neither the understanding nor the will are more than powers: 'it is the Mind that operates, and exerts these Powers; it is the Man that does the Action, … or is able to do'.

Why was the title of the Essay chosen to refer to 'human understanding'? The epithet 'human' made clear that the book was about man and not about the understanding belonging to God, angelic spirits, or 'intellectual corporeal Beings, infinitely different from those of our little spot of Earth' elsewhere in the universe. The term 'understanding' was more appropriate than 'mind' or 'soul' partly because Locke's inquiry was principally epistemological and partly because it was directly concerned just with conscious perceptions or thoughts, and these are precisely the extension of the understanding; mentality outside the understanding is pertinent only inasmuch as it gives rise to acts or objects of the understanding; e.g. the discussion of the will, liberty, and necessity in II. xxi is relevant to the subject of the understanding inasmuch as the latter has ideas of them.

Locke classified the understanding's acts of perception into three types; only the last two match our usual sense of 'to understand'. There are perceptions of 'Ideas in our Minds', of the signification of signs, and of 'the Connexion or Repugnancy, Agreement or Disagreement' between our ideas; he took stock of these three sorts chiefly in Books II, III, and IV, respectively. He first investigated the origin of the ideas in our minds. He maintained that the individual's experience in 'Observation employ'd either about external, sensible Objects; or about the internal Operations' of its own 'perceived and reflected on' by itself is that which supplies it 'with all the materials of thinking', a principle he pursued through Book II in reference not only to ideas thus plausibly derived from sense-experience or reflection, but also to ideas, e.g. of space, time, number, infinity, and causality, which were a much sterner test of his hypothesis, this being, he trusted, all the more strongly confirmed by his empirical accounting of them. His assumptions, arguments, and conclusions in this connection were soon disputed, notably by Leibniz (1646-1714), first in personal communications to Locke and then in his long Nouveaux essais sur l'entendement humain. Perhaps Leibniz's most effective criticism resulted from deploying his doctrine of subconscious thought, the very possibility of which Locke had repeatedly rejected out of hand. Locke denied that we were born into the world with any completed or incorrigible knowledge, or with any of its conceptual constituents; whether pertaining to the nature of things or to our conduct, an elimination he sought to justify in the main run of chapters of Book I, whose concluding chapter, against innate ideas (as distinct from innate principles, which he had already dealt with), afforded a suitable transition to Book II.

Locke's epistemology is notoriously a 'way of ideas': 'Having Ideas, and Perception [are] the same thing'; ''Tis evident, the Mind knows not Things immediately, but only by the intervention of the Ideas it has of them'…. What exactly these intervening 'ideas' are, and whether experience can be satisfactorily resolved into them or so-called ideas of other sorts, are among Locke's immediate difficulties. Our general knowledge of things has two branches in his account—which runs in two divergent directions. He has a conventionalist (apriorist) view of knowledge regarding our human concepts of the essences of things: 'Truths belonging to Essences of Things, (that is, to abstract Ideas) are eternal, and are to be found out by the contemplation only of those Essences'. But he has at the same time an empiricist (aposteriorist) view of other aspects of the knowledge of things. First, the existence of things is to be known only from experience. Secondly, the knowledge of the coexistences of qualities of a (sort of) substance is limited by our mind's inabilities to conceive connections and depends on experience,

since we neither know the real Constitution of the minute Parts, on which their Qualities do depend; nor, did we know them, could we discover any necessary connexion between them, and any of the secondary Qualities: which is necessary to be done, before we can certainly know their necessary coexistence…. Our Knowledge in all these Enquiries, reaches very little farther than our Experience…. we are left only to the assistance of our Senses, to make known to us, what Qualities [Substances] contain. For of all the Qualities that are co-existent in any Subject, without this dependence and evident connexion of their Ideas one with another, we cannot know certainly any two to co-exist any farther, than Experience, by our Senses, informs us.

For this and related reasons he maintains that inquiries into the nature of things have exceedingly limited prospects of attaining the status of strict science.

Since Locke, epistemology and the philosophy of science (and the philosophy of mathematics) have strained at the problem of the conflict between conventionalism and empiricism in respect of general knowledge, either by eliminating one of the alternatives—conventionalism at the cost of certainty, or even rational probability; empiricism at the cost of meaningfulness, verifiability, or innovation—or by trying to show how they can be reconciled. This is one of many Lockian problems which have continued to attract philosophers' vigorous, and, happily, increasingly rigorous attention….