The Life and Writings of George Berkeley (1685–1753). In Bishop Berkeley we have the finest type of Irish mind. In his brilliant mental powers and idealistic theory he reminds us of that wonderful Irish scholar of the Middle Ages, John Scotus Erigena. Berkeley was acutely critical, and yet he possessed a childlike religious faith. He combined an insatiable longing for knowledge with an ardent missionary zeal. “Berkeley was a born child of Plato, a lineal descendant of a race whose origin is afar off and is divine.”40 He was one of those exceptional minds that begin to bring forth their intellectual offspring when they are young. Berkeley began to publish at the age of twenty-four, Hume at twenty-eight, Descartes at forty-one, Locke at fifty-eight.
We shall divide the life of Berkeley into three periods.
1. His Early Training (1685–1707). Nothing is known of Berkeley’s early years, except that he was born in Kilkenny, Ireland. He was educated at the Eton of Ireland, the Kilkenny school, where Swift had been a pupil; and it is known that one of Berkeley’s schoolmates was Thomas Prior. Berkeley entered Trinity College, Dublin, at fifteen, and graduated at nineteen. Scholasticism was still influential at Trinity, but new sciences, such as botany, chemistry, and anatomy, had been added to the curriculum. There, too, the young Berkeley found that Locke’s Essay was much discussed, and that Newton, Boyle, Malebranche, Descartes, and Leibnitz were widely read. From this early date Berkeley began to keep a book of his own philosophical reflections, calling it his Commonplace Book. From it and from his philosophy it would appear that Locke and Malebranche were the most powerful philosophical influences upon him.
2. As Author (1707–1721).
Berkeley remained at Dublin as tutor and fellow five years after his graduation. In 1709 he was ordained deacon in the English church. He published two mathematical tracts in 1707, his Theory of Vision in 1709, his Principles of Human Knowledge in 1710. The Theory of Vision and the Principles of Human Knowledge were practically a statement of his philosophy. They have been compared thus: the Theory of Vision teaches that “all that we see is our sensation”; the Principles of Human Knowledge teaches that “all that exists is our knowledge.” Berkeley then went to London, where he was admitted to the court of Queen Anne and also to the circle that included Steele, Swift, Addison, and Pope. Berkeley showed himself humble, wise, considerate, and unselfish, and although he was shocked at the court life, he on his side charmed every one whom he met. He wanted to make his idealism better understood, and so he published it in the form of a dialogue between a realist and an idealist. This publication was called Three Dialogues between Hylas and Philonous (1713). He then made two journeys to the Continent—1713–1714 and 1716–1720—and spent much of the time in Italy, where he absorbed its literature. The South Sea swindle turned him to economics, and in 1721 he published an Essay toward Preventing the Ruin of Great Britain.
3. As Priest and Missionary (1721–1753).
Berkeley was appointed Dean of Derry in 1721 at a salary of £1100. Although he threw himself into his work with his accustomed zeal, there had already appeared in his mind the conception of an ideal society, where church and state would be united. He was disgusted with the worn-out European society, and wanted to remove the youth to a colony where there would be no temptations. He raised a large sum of money for this purpose, and obtained the promise of a grant from the government of £20,000, gave up his deanery, and sailed for America. He intended to settle in Bermuda and there to found an ideal State, which should also be a centre for the conversion of the American Indians to Christianity. The promised grant from the English government did not come, and Berkeley got no farther than Newport, R. I., where he lived three years. While at Newport he wrote Alciphron, the Minute Philosopher, and published it in England in 1732. The records of Trinity Church in Newport show that he preached there many Sundays. He gave several books to Harvard and Yale Colleges. At Newport he was visited by Samuel Johnson, an Episcopal missionary, who afterwards became president of King’s College in New York. Johnson was converted to Berkeley’s idealism, and through Johnson the doctrine was received by Jonathan Edwards, his pupil.
From 1734 to 1752 Berkeley was Bishop of Cloyne. He was devoted to missionary work among the poor, and many of his people being afflicted with an epidemic of influenza, he treated them effectively with tar-water—a remedy he had learned from the Indians. He published Siris, an essay on the philosophical virtues of tar-water, in 1744. In 1752 he went to Oxford to live, and in 1753 he died.
The Influences upon the Thought of Berkeley. Berkeley’s philosophy shows little development after his first publications. With the exception of Siris, which contains much Platonic idealism, the later works of Berkeley are scarcely more than an elaboration of his early thought in the Theory of Vision and the Principles of Human Nature. We should infer, therefore, that the only philosophical influences upon Berkeley were the original springs at which he drank as a youth. Moreover, he always speaks with the dogmatic certainty of one who has drawn his material from but few sources. Never does he exhibit the indecision of a man who is embarrassed by many points of view. The two chief influences upon him were Locke and Malebranche. The influence of Locke was partly of the nature of a reaction: Berkeley accepted Locke’s psychological analysis, but reacted from Locke’s “common sense” dualism as early as the time of his student life at Trinity. Malebranche, with his theory of “occasional causes,” reinforced his opinion along the line that his reaction took. But Berkeley’s own incisive genius had a relatively greater influence in dictating the course of his philosophy than is usually the case. His mind was precocious, fertile, and continuously versatile. Furthermore, Berkeley’s simple religious nature seems to have been an important factor in determining his intellectual belief. His peculiar idealism could take root only in a mind inspired by faith.
The Purpose of Berkeley. The life and teaching of Berkeley were dedicated to the true interests of religion. He may be called the religious Enlightener. He would not, like the deists, strip religion bare of dogma, but he would unlimber dogma and rational philosophy so that they would be of service to religion. His purpose was to free scholasticism on the one hand, and rationalism on the other, from abstractions and obscure terms, and thereby bring about a union of faith and knowledge. Berkeley looked upon himself as a crusader who would retake the Holy Land for the spiritual individual.
We have remarked that one of the presuppositions of this period of the Enlightenment is the independence of the individual. The individual around which Berkeley’s philosophy centres is the spiritual individual, and is therefore unique even for this period. Such an individual is superior to his environment because he belongs not to a material world, but to a community of religious beings who can talk and walk with God. The English Enlightenment passed from Locke to Berkeley. The inner life came into complete ascendency and the spiritual individual emerged. From the Lockian philosophy, with its many contradictory motives, there appeared the audacious one-sided philosophy of Berkeley, with its proclamation of the reign of spirituality. It stood in marked contrast with the development of the Enlightenment in France—a development of materialism and material atoms. The spectral although stubborn boundaries of the unknowable material world, which Locke supposed to shut around the powers of the human intellect, crumbled before the hand of Berkeley.
The casual reader of the history of thought is, however, often disconcerted at the appearance of such a philosophy as Berkeley’s in this period of empiricism, and especially as the immediate follower of Locke. The English school is called the empirical school, and yet Berkeley is also called an idealist. But we must remember that empiricism and idealism are not antithetical. Empiricism refers to the source of our knowledge; it means that all our knowledge is primarily derived from sense-perceptions. These sense-perceptions may be of two kinds: they may be (1) psychological facts, or (2) material facts. Berkeley was, like Locke and Hume, an empiricist of the first class; and yet because he denied the independent existence of material facts, he was also an idealist. He was an empirical idealist, just as the French philosophers of the Enlightenment were empirical materialists. The critic may find that Berkeley is not a consistent empiricist, to be sure, but neither was Locke. Berkeley started out by affirming the testimony of experience against scholastic speculation and abstraction; yet all along he assumed the scholastic conception of mind. Nevertheless, this assumption of the individual makes Berkeley a true child of the Enlightenment.41
Berkeley’s General Relation to Locke and Hume. The growth of this English school from Locke to Hume is not difficult to understand or to remember. It is not so much a page in the history of metaphysics (the nature of reality) as in epistemology (the theory of knowledge). Locke asks, What can we know? And he replies to his own question, that we can know our “ideas.” At the same time he assumes the existence of a spiritual substance on the one side, and a material substance on the other. Neither of these is an idea, in the sense that it is an object of knowledge. The advance of Berkeley from Locke and of Hume from Berkeley was one of cancellation. Berkeley cancelled the material substance, because the material substance is not an idea. Hume then consistently enough asked, Why not for the same reason cancel the spiritual substance? The spiritual substance is not an idea or object of knowledge. We have no more right to assume it than the material substance. The only things we know to exist are our ideas. The development of the English school may be briefly put as follows:—
Locke,Spiritual substance—ideas—material substance.
Berkeley,Spiritual substance—ideas.
Hume,ideas.
Hume is Locke made logically consistent. Berkeley went only halfway. Hume among these three was the only self-consistent empiricist. On the assumption that all knowledge is derived from sense-perception the history of the English empirical school was a history of the restriction of knowledge.
Berkeley’s Points of Agreement with Locke. Berkeley starts from Locke’s psychological analysis as the basis of his own theory. The purely scientific aspect of the contents of mind as classified by Locke does not call for particular criticism from him. Logical classification does not seem to concern him very much, and while he accepts Locke’s analysis, he often calls Locke’s classes by other names. He commits himself to Locke’s psychological empiricism in the first sentence in his Principles: “It is evident to any one who takes a survey of the objects of knowledge, that they are either ideas actually imprinted on the senses; or else such as are perceived by attending to the passions and operations of the mind; or, lastly, ideas formed by the help of memory and imagination—either compounding, dividing, or barely representing those originally perceived in the aforesaid ways.” Our knowledge, therefore, deals only with ideas. There are the simple ideas of sensation and reflection, and ideas compounded from these.
Besides accepting the psychological analysis of Locke, Berkeley also adopts without question the assumption common to Locke and all the philosophers of the Enlightenment,—the assumption of the independence of the individual soul. “But besides all the endless variety of ideas or objects of knowledge, there is likewise something that knows or perceives them—what I call mind, spirit, soul, or self. By which I do not denote any one of my ideas, but a thing entirely distinct from them, wherein they exist, or, which is the same thing, whereby they are perceived.”
Berkeley, therefore, (1) agrees with Locke that all knowledge is derived from sense-perception, i. e. he agrees with Locke’s empirical psychology, and (2) he also agrees with one of Locke’s assumptions, viz., that the spiritual substances exist.
The Negative Side of Berkeley’s Philosophy. We have now pointed out Berkeley’s general relation to Locke and Hume, and more in particular his agreements with Locke. We are now prepared to examine the teaching of Berkeley by itself.
Berkeley was obliged to devote a good deal of time to the negative side of his philosophy. Just as Locke could not construct an empirical psychology until he had disclaimed all allegiance to innate ideas, so Berkeley could not construct an idealism until he had brought to bear in a polemical fashion all his forces against abstract ideas. Of his two masterpieces he devotes the entire essay on the Theory of Vision and a good part of his Principles of Human Nature to this end.
1. In proof of this he advances his analysis of abstract ideas. He not only denies that abstract ideas have a corresponding external reality, but he even denies that abstract ideas exist in the mind itself. The deception in abstract ideas arises from the use of words as general terms. Words are always general; ideas are always particular. There is never an idea that exactly corresponds to a word. Words are useful not as a conveyance of ideas, but for inciting men to action and arousing the passions. Whenever a word is used, what we think of is the particular sense, idea, or group of sense objects that give rise to it. For example, the word “yellow” cannot be employed by us except in connection with the thought of some particular yellow thing. Berkeley is a nominalist of the extremest type.
2. Again Berkeley seeks to show, by demolishing the distinction between primary and secondary qualities, that matter as an abstract idea has no existence. This distinction was as old as the Greek, Democritus, and was accepted by Locke. We have already described it: of a thing like a lump of sugar, the sense qualities of whiteness, roughness, sweetness, etc., are secondary because they depend upon our sensations for their existence; they are the ways in which our organisms are affected, and not true copies of things; the mathematical qualities, form, size, density, impenetrability, are primary because they exist independent of our senses and are true copies of things. Hobbes had already shown that such a distinction is erroneous, and Berkeley followed him by maintaining that all qualities are secondary. The size and impenetrability of a body depends as much on sense-perception as its sweetness and color. At some length in his Theory of Vision Berkeley takes up the question of the solidity, or third dimension, of a material body, and shows that it is an inference depending on sensations arising from the convergence of the two eyes and complicated by the sensations of touch.
Berkeley professed to be pleading the cause of the man in the street who wants a philosophy that is real “common sense.” He maintained that the conception of matter is only a philosophical subtlety for those philosophers who seek for something beyond perception. The man in the street wishes to explain things as he finds them, and not to seek mysterious abstractions which philosophers say in one breath that we know, and in another that we cannot know.
Therefore, while Berkeley agreed with Locke’s assumption of the existence of the spiritual substance, he departed from Locke in denying the existence of a material substance. Berkeley accepted, therefore, one of the two assumptions common to the Enlightenment, but he denied the other. Now Berkeley was trying to prove a thesis. He was controlled by the ideal of his ardent religious nature to free religion from false philosophy. He felt that the foes of religion—atheism and materialism—had employed effectively abstract ideas, which had been one of the weapons of religion, against religion itself. Berkeley concentrated his attack against the traditional scholastic conception of abstract ideas in general and the abstract idea of matter in particular. Abstract ideas have no existence; the idea of a material substance is an abstract idea and therefore has no existence. Berkeley was bound from the beginning of his religious crusade to explain away the existence of material substance.
The Positive Side of Berkeley’s Philosophy.42 In the construction of his theory in a positive way Berkeley abridged the dualism of “common sense,” and asserted that the abridged form was better. He converted the dualism into a religious hypothesis, but it was a dualism still,—a dualism of minds and their ideas. Berkeley then set to work to show how much better his theory would explain the problems of knowledge. “Berkeley sought to humanize science.” He set the spirit free by relieving it of the falsities of the old dualistic assumption, but the usefulness of his abridgment lay in its solution not of metaphysical, but of epistemological problems.
1. Berkeley’s theory may be summed up in his own abbreviated statement of it,—Esse est percipi (to be is to be perceived). Or it may be stated in that figurative and oft-quoted paragraph, “Some truths there are so near and obvious to the mind that a man need only open his eyes to see them. Such I take this important one to be, viz., that all the choir of heaven and the furniture of the earth, in a word all those bodies which compose the mighty frame of the world, have not any subsistence without a mind—that their being is to be perceived or known.” Or we may state Berkeley’s position in the terms of a modern interpreter43 of him: “All objects are mentally discerned; all objects are mentally constituted.” Berkeley means that the existence and character of all objects are within the confines of consciousness, and there are no objects outside of consciousness. As sense-perceptions they have reality; as memories they lose their warmth and distinctness; but they are not objects at all when neither perceived nor remembered. These objects are always colored by the sense-perception. They are received through the consciousness, and constituted by the consciousness. Minds and their ideas are all that exist.
2. Berkeley does not try to prove the existence of the mind or soul, nor does he attempt to show that we perceive the soul. But in the spirit of the Enlightenment he hardly questions its reality. He takes its existence for granted, and like the philosophers of the period he makes a direct appeal to consciousness. “I know I am conscious of my own being.” Like Locke and Descartes he alleges the direct intuition of the self. In the Principles he speaks of “a notion of our own minds or spirits.” Since the ideas are copies of other ideas, there can be no idea of the soul; but the “notion is like the spirit that knows it.” We have therefore direct knowledge or notion of ourselves in knowing our ideas; we have direct knowledge of something superior to the ideas, an activity whose reality consists not in being perceived, but in perceiving. Indeed, he made the assertion in his Commonplace Book, which he began in college, that nothing properly does exist but conscious persons. All other things are not so much existences as signs of the existences of persons. One is absolutely certain of what one means by “I.”
3. Spiritual substances are sufficient and adequate to explain all ideas. There is no difficulty in explaining the images of our own minds, for our minds control them. But what explains the existence of our percepts over which we have no control? What substantial support have they if we remove the “material hypothesis”? Suppose I grant that I exist and have control of my imaginative ideas, and that other minds exist and have control of their imaginative ideas, how then, I ask Berkeley, am I to explain the great world of perceptions over which neither I nor other men have control?
Berkeley’s general psychological position must be summarized here in order to answer this important question. It is as follows: (1) All things are nothing more than perceptions. (2) All ideas, both perceptions and images, are passive, and must be caused by something in itself active. (3) Souls are active and the cause of ideas. The question then is, What soul is the cause of our perceptions? Perceptions are ideas, are passive, but they are the ideas of whom? Repudiate the material substance, and what is the cause of perceptions?
Perceptions are not originated by me; they cannot be self-originated, because they are passive and not active; they cannot be originated by a material substance, because it does not exist. Their origin must be sought in the infinite spirit, or God. If you will examine the ideas which constitute what we call nature objects, you will observe these significant characteristics about them, to which attention has already been called. They have, as we have said, a strength, liveliness, distinctness, and orderliness that distinguish them from imaginations. They are God speaking to us in His orderly way. Nature objects are the language of God. The regularity and dependability of the world of nature reveal the character of the Being whose language the world of nature is. They reveal a Being who is intelligent, infinite, omnipotent, and benevolent. The regularity of the changing seasons, the constancy of the heavenly bodies to their orbits, the provision of the earth for man—all the laws of nature are the language of an orderly Being.
Now we see the importance of Berkeley’s deviation from Locke in his (Berkeley’s) conception of all ideas as passive. All ideas being passive, there must be a cause of them. The only active causes are spirits. I am the cause or perceiver of my own imaginations. I perceive another’s movements and know that another person or spirit must be the cause. When nature speaks in its invariable and purposive harmony, I know that an infinite spirit is the cause. We are indeed living in a society of spirits, who speak to one another in their own language.
The doctrine of Berkeley strikes beginners and people who temperamentally cannot understand it, as absurd. The reduction of the trees, sky, etc., to ideas is a theory that has brought down all kinds of ridicule upon it. When Dr. Johnson heard of it, he is said to have stamped his foot upon the ground, and thereby refuted it. Byron is quoted as saying, “If there is no matter, and Berkeley has proved it, it is no matter what he said.” Others have asked if we eat and drink ideas and are clothed with ideas. But Berkeley never doubted the existence of material objects, and the point of his theory is missed if we think that he did. What he denied is the existence of an unknown substance, matter, behind external objects. “The table I write on exists, that is, I see and feel it; and if I were out of my study I should say it existed, meaning thereby that if I were in my study I might perceive it or that some other person does perceive it.”
Another question has been asked of Berkeley which goes deeper. If to be is to be perceived, what existence has a tree in the forest that no one has ever perceived. What existence have past events that are forgotten? Berkeley has considered this objection and has answered it. When he says that existence depends upon perception, he does not mean merely my own perception. Berkeley is not what in philosophy is called a solipsist (solus and ipse), i. e. one who believes that nothing exists but himself and his modifications. A thing may have existence in the mind of some one else. If the thing has never been perceived by any human being, it is perceived, if the thing exists, by the mind of God. The modern scientist assumes the existence of matter in the whole universe. Berkeley assumes the existence of a perceiving God. One is the materialistic and the other the religious explanation of the universe.
The Life and Writings of David Hume44 (1711–1776). Hume’s life bears some marks of external resemblance to Berkeley’s. After periods of training that differed very greatly in point of discipline, but were almost the same in point of time, both produced, at about the age of twenty-five, their most important philosophical works. Both turned from philosophy to other pursuits—Berkeley to missionary work at the age of thirty-six, and Hume to politics at the age of forty-one. There the resemblance between the two men ceases; for they were antipodal by nature, and animated by different purposes. The enthusiastic nature of Berkeley is in marked contrast with the unimpassioned nature of the Scot. Hume was unimaginative to the last. He was unimpressed by the legends of the border where he lived; he had no love for nature and no appreciation of art. “While Hume’s intellect was imperial, his sympathies were provincial.” Berkeley’s sympathies were imperial and his intellect was in their service. Hume was a man of kindly disposition and of moderate temper, yet he was vain, and interested above everything else in his own reputation. No object seemed worth while to him, unless it made for the improvement of his talents in literature. The failure of the Treatise was a blow from which he never recovered. Always afterward he had an eye to popularity, and this is important in making up our judgment about him. All his works after the Treatise were written to please his readers and for personal success. Locke the Englishman, Berkeley the Irishman, and Hume the Scotchman came from the same middle class of society, had university training, were engaged in public service, and are to be classed in the same empirical school of philosophy. But they were personally very different kinds of men, and were types, although perhaps not representatives, of their nationalities.
1. Period of Training (1711–1734). Hume was born in Edinburgh and lived there and at Ninewells on the border. He was a student at Edinburgh University (1723–1726) and studied law the next year. He was in business in Bristol in 1734. In all the occupations of this period he was unhappy.
2. Period of Philosopher (1734–1752). From 1734 to 1737 Hume was in retirement in France, especially at La Flèche, where he wrote his Treatise on Human Nature. He returned to Edinburgh in 1737 and published his Treatise (1739–1740). It was read by nobody and was an absolute failure. So he rewrote Book I in 1748 and called it the Enquiry concerning Human Understanding. Hume’s full statement of his theory of knowledge is contained in the Treatise and not in the Enquiry. He rewrote Book III in 1751 and called it the Enquiry concerning Principles of Morals, “of all my writings, incomparably the best,” and in 1757 he published Book II as an Essay on the Passions in Four Dissertations. He became acquainted with Adam Smith in 1740; he published Essays, Moral and Political, in 1741–1742, and was a tutor in 1745, because he needed money. In 1746–1748 he became secretary in the English military embassy to Vienna. In 1751, the same year that he was recasting the third book of the Treatise, he wrote his Dialogues concerning Natural Religion, which was not published until 1779. His autobiography was also published posthumously.
3. Period of Politician (1752–1776). In 1752 Hume published his Political Discourses, “the only work of mine that was successful on its first publication.” In 1754–1761, while Librarian at Edinburgh, he wrote and published his History of England. This work was the first serious attempt since the Revolution to give an impartial account of the earlier struggles against the Stuarts. Through it he at last got great fame, and fortune followed in its wake. In 1757 came his restatement of Book II of the Treatise. In 1763–1765 Hume was secretary of the English Embassy at Paris, and he was made much of by French society. The thought of the French Enlightenment had advanced far enough to entertain him and his doctrines. Hume met Rousseau at this time. Later Hume was visited by Rousseau in England and was badly treated by the eccentric Frenchman. He says that Rousseau sins at the foundation. Hume was appointed Under Secretary of State in 1766; he returned to Edinburgh in 1769, and died in 1776.
Influences upon the Thought of Hume. The writings of Hume show no erudition, and for that reason it is uncertain what were all the sources from which he drew. He does not mention Descartes, for example, although he wrote his Treatise at La Flèche in the shadow of the school where Descartes was educated. It is probable, however, that Hume was influenced at least by the Greek philosophers of the Hellenic-Roman Period, and by Locke. During the years after Hume’s student life at the university, he pored over the writings of the Roman Stoics in the library at Ninewells, and he felt the influence of Cicero, Seneca, and Plutarch. Hume read extensively, and he reacted from his reading. He became so dissatisfied with the past that he put it aside, in the belief that the true philosophy had not yet been written. In this reaction from the past he was influenced along the lines of Locke and Berkeley. He admired the advance that Berkeley had made over Locke, and naturally took a further step in the same direction. Hume was also acquainted with the writings of Hobbes and with the history of the English theories of morals.
In 1740 he became acquainted with Adam Smith, the political economist, and Hume’s Political Discourses (1752) anticipated Smith’s classic Wealth of Nations. At this time (1752) he turned with all other Englishmen from the discussion of philosophical to political topics. There are many points of resemblance between Smith and Hume, especially in their ethical doctrine.
Dogmatism, Phenomenalism, and Skepticism. Hume liked to speak of himself as a skeptic, but philosophically speaking he was skeptical only of the dogmatic Rationalism of the Renaissance, which had made unlimited claims for the human reason. Hume maintained in the spirit of the Enlightenment that the human mind deals with ideas and not with reality. Human knowledge has therefore its limits. More consistently than Locke or any one else in the Enlightenment, he tried to show the limits and extent of human knowledge.
Pure skepticism is the denial that there is any such thing as truth; pure dogmatism would be the deductive explanation of all problems from a set of infallible principles. It would be hard to find an absolutely true example of skepticism or dogmatism, for generally philosophical theories are a mixture of dogmatism and skepticism. Pyrrho is often given as an example of the pure skeptic, but Pyrrho, like all other Greeks, never for a moment doubted the existence of an external, material object (vol. i, chapter xii). Spinoza is a fairly good example of a pure dogmatist, but he developed his Ethics by means of interpolated principles not in his original assumptions. A thorough-going skeptic would have to be a modern—not a Greek—who would deny that truth can be known and that things exist. This was not Hume’s contention. He affirmed the validity (1) of mathematical reasoning (2) and of matters of fact, and (3) the probability of the natural sciences. Hume may correctly be called a phenomenalist, a positivist, or an agnostic. So far as he maintained that there are some things which the reason cannot know, he is an agnostic. In his affirmation that we can know ideas and only ideas, he is a positivist. In his affirmation that ideas are the only existences, he is a phenomenalist. Are external objects the cause of sensations? Experience is dumb. Have external objects an existence? Experience is dumb. Are souls the substance of our thoughts? Experience is dumb. But mathematics has truth, experience is beyond question, and the workings of nature are probable.
We shall find Hume to be the keenest critical mind of this critical period of the Enlightenment. He is profoundly serious in his examination of the roots of the intellectual life. He is past-master in the art of raising questions. He not only shows that the fundamental theoretical problems are still unsolved, but he also calls to account the hitherto untested assumptions of practical life. But this is criticism, positivism, phenomenalism, or agnosticism, and not skepticism. He speaks of his doctrine as like that of the Middle Academy, in contrast with that of Pyrrho. He says that excessive skepticism upsets activity, employment, and common occupations. The conclusions of the intellect never agree with our natural instincts. Every time positive skepticism appears, nature destroys it.
Hume’s conclusion as to the practical attitude of the positivist toward life can best be stated in his own words (Treatise, Book I, Conclusion): “Shall we then establish it for a general maxim, that no refined or elaborate reasoning is ever to be received? If we embrace this principle, we run into the most manifest absurdities. If we reject it in favor of those reasonings, we subvert entirely the human understanding. We have, therefore, no choice left, but between a false reason and none at all. Most fortunately it happens that since reason is incapable of dispelling these clouds, nature suffices to that purpose, and cures me of this philosophical melancholy. I dine, I play a game of backgammon, I converse, and am merry with my friends.—No: If I must be a fool, as all who reason or believe anything certainly are, my follies shall at least be natural and agreeable. In all the incidents of life we ought still to preserve our skepticism. Where reason is lively and mixes itself with some propensity it ought to be assented to.”
The Origin of Ideas. Locke did not proceed to the construction of his theory of knowledge until he had disclaimed at length his belief in the existence of innate ideas. Berkeley went further and made his polemic against the existence of all abstract ideas. Hume went still further and denied that any ideas existed except those derived from impressions. Locke’s attack upon innate ideas was an attack upon unverified tradition; Berkeley’s attack upon abstract ideas was an attack upon materialism; Hume made a general attack upon rationalism. The psychology of Hume is thus made simple. It is a cancellation of the factors incompatible with strict empiricism—the factors which he found in Locke and Berkeley. Hume’s empirical psychology is simply this: every idea is the image or copy of an impression.
What is an impression? Impressions are of two classes: (1) sensations or outer impressions; (2) feelings or emotions or inner impressions. Impressions are never mistaken, because they always have a very lively and vivid character. What is an idea? It is the copy of an impression. An idea should never be mistaken for an impression, because it is fainter and more feeble than the impression of which it is the copy. For example, the sensation of yellow is more vigorous than the thought of yellow; the feeling of anger more vivid than the thought of anger. Impressions are simple and elemental. Can we go back of them and find their origin? We cannot. We receive impressions; echoes of impressions linger as ideas; ideas may be compounded with other ideas. Hume deals in his criticism mostly with the compounding or combining of ideas, but this is the sum and substance of his psychological analysis of our mental life. The following table will help us.
| Perceptions (= mental states) |
 |
Impressions (= original) |
|
Sensations or outer impressions |
| Feelings or inner impressions | ||||
| Ideas (= derived) |
|
Memories or an exact reproduction of an impression or of a combination of impressions | ||
| Imagination or a combination, separation, and transposition of impressions according to the imagination’s own laws. |
It should be noted, however, that the above classes are not coördinate according to Hume. Impressions are prior to ideas, and of the impressions the feelings or inner impressions are “posterior to the sensations and derived from them.” Hume is a sensationalist, for the most original of the impressions are sensations.
The Association of Ideas. Since nothing can enter the mind except through the two portals of outer and inner impressions, every idea in the mind is the copy of one or several impressions. How then can there be any such thing as error? Error arises from the understanding and imagination in their manipulation of the impressions—from the faculties of the mind combining, separating, and transposing the impressions and their memories. An idea resulting from such transposition may and often is referred to an impression different from the one of which it is the copy.
What does Hume mean by the faculties and powers of the mind? He does not mean that the mind with its functions exists as a reality, since all that exist are impressions and the copies of impressions or ideas. Hume means by mental faculties and powers the various modes by which ideas combine. Hume makes no distinction between memory, imagination, judgment, conception, etc., except (1) as different groupings of ideas and (2) as accompanied by different feelings. The whole mental life and the faculties of the mental life are nothing but an association of ideas. Isolated ideas are explained as copies of isolated impressions; and from these ideas are derived groups of ideas which we call trains of thought. Why do ideas group themselves together? The only answer is that it is the nature of ideas. Hume frequently speaks of these associative relations as “the manner of conceiving ideas.” He also says that there is a “gentle force” or “determination” of the ideas to relate themselves with other ideas. Given the impressions and their relations, and Hume will explain the whole knowing process. Associative relations take an important place in Hume’s theory, but some critics say that they are interlopers; that he has introduced them by a back door; that they are not mentioned in his psychological inventory.
But to Hume there is nothing mysterious about the association of ideas. They are combined, transposed, augmented, and diminished according to fixed rules under mechanical laws. Their relationship takes place without freedom. Impressions occur in the way they happen to occur. Ideas combine in the way they happen to combine. Relations between ideas are accidental and external. There is only one quality of ideas that does not depend on its accidental relation to other ideas. This is the quality of non-contradiction. This is the necessary property of an impression. An impression must be what it is, and cannot be conceived as having properties contrary to its own nature. The quality of identity in an impression is intrinsic and necessary.
According to Hume, there are three fundamental ways in which ideas associate, called the three laws of association. (1) There is the law of resemblance or contrast, by which the occurrence of a thing calls up a similar thing or its opposite. Mathematics is based upon this law of the resemblance, the contrariety, and the quantitative relations of ideas. (2) There is the law of contiguity in time and space, by which things happening together in time and space are recalled together. Upon this law are based the descriptive and experimental sciences. (3) There is the law of causation, upon which religion and the metaphysics of the world of nature are based. The question with Hume is, How is he to explain all these laws of association as derived from impressions? If they cannot be derived from impressions, then his theory that all knowledge is derived from impressions goes to the wall. The Rationalists and even his predecessors, Locke and Berkeley, had conceived mathematical propositions and causation as underived and in the nature of things. If Hume is to establish his doctrine of complete sensational empiricism, here is his test.
These associations, and not isolated impressions, are the objects of human interest, inquiry, and investigation. Hume makes a further reduction of associations by his well-known classification of them as either “relations of ideas” or “matters of fact.” Associations of contiguity and associations of causation are “matters of fact,” while associations of resemblance are “relations of ideas.” Furthermore, Hume looks upon associations of contiguity as those of outer impressions, associations of resemblance as those of inner impressions, while associations of causation are not what they are alleged to be, but are derived from some inner impressions.
| Objects of Knowledge | |
Matters of Fact | |
1. Contiguity association | Outer impressions | Descriptive Sciences |
| 2. Causation association45 | Inner impressions | Metaphysics | ||||
| Relations of Ideas | |
3. Resemblance association | Inner impressions | Mathematics |
The Association of Contiguity. This is the most elementary of the three classes of association, and concerns the spatial and temporal order in which impressions come to us. Two impressions come at the same time or in succession, and when one of them is remembered, the other is likely to be remembered also. We see a man and hear his name; when we remember the man’s face, we may remember his name also. Hume maintains that this association of succession or coexistence is given with the impressions themselves. It is the order of the outer impressions. We perceive the order of the outer impressions with the same certainty that we perceive the contents of the impressions. This is the only certainty we have about “matters of fact,”—a certainty of the exact order of our immediate outer impressions. We know the order in which our impressions do occur, but, as we shall see, when we argue from this that our impressions must recur in the same order we are involved in a fallacy. Any order may recur. The fact that the sun rises in the east to-day does not make certain that it will rise in the east to-morrow. It is only a matter of probability, however many times repeated. There is no certain science of “matters of fact.”
The Association of Resemblance. This is a clear and distinct association which is given with the impressions. When we have an impression, we see intuitively its similarity or difference to other impressions, and the degrees of likeness and unlikeness. The face of one man reminds us of another man, or we contrast it with a brute’s face. This association concerns only inner impressions, while the association of contiguity concerns outer impressions. This has to do with the “relation of ideas,” while the association of contiguity has to do with “matters of fact.”
1. Mathematics. But there is this difference between the association of resemblance and that of contiguity—upon resemblance is founded a demonstrative science. This is mathematics—the sole demonstrative science. The subject-matter of mathematics consists of the possible relations between the contents of our ideas—the possible relations between our inner impressions. These relations are intuitively known by us, and out of them we get a science of complete certainty. We make a comparison between the magnitudes in the contents of ideas, and we analyze their regularity. This is mathematics, and it is a perfectly legitimate science. Because it confines itself to the relations between ideas, and has nothing to do with “matters of fact,” it can be a demonstrative science. All mathematical knowledge is restricted to the study and verification of ideas, and has therefore nothing to do with the external world.
2. The Conception of Substance: Hume’s Attack on Theology. But the association of resemblance has been made the basis of a common illusion. It has been made to transcend its proper sphere of a relationship among inner impressions; and resemblance between ideas has been taken by people generally to mean metaphysical identity or substance. It has been transformed from a relationship between ideas to a relationship between “matters of fact.” Now substance is evidently not an association given with the impressions, like their temporal and spatial order in the association of contiguity, nor is it mere impression of resemblance. Substance is the conception of an unknown, indescribable something back of impressions. There is the conception of the material substance or matter, and the spiritual substance or the soul. How did such illusory conceptions arise? If Hume rejects them as matters of real knowledge, he must nevertheless explain their psychological origin. The illusory idea of substance originates from the similarity of the frequent conjoining of certain impressions. The impressions—sweet, rough, white, etc.—occur together so often that the imagination creates the conception of the substance of sugar behind them. This arises not from the first experience, but after the association of impressions has been observed a large number of times. From the frequent association of ideas arises the feeling of their necessary coexistence. Thus do we come to have the idea of a material substance.
Hume evidently follows Berkeley in his criticism of material substance. But Berkeley went only halfway. Berkeley had found that bodies were only conjunctions of sensations, and he had rejected as meaningless the unknown substance behind them. He did not see that the same attack could be made upon spiritual substances. Berkeley’s argument against the substance of the cherry could be used against the Ego or the Soul. Have I the impression of my Ego? Can I touch it or see it? The simple test shows that I know nothing about it, and I cannot affirm whether or not it exists. But if the conception of the Soul has no reality as an object of knowledge, how can it be psychologically explained? How does it arise in the mind? The idea of the Soul is due to the frequent reappearance of the same trains of thought in my mind. Their similarity gives rise to the feeling that a metaphysical identity, or Soul, exists behind them.
The Association of Causation: Hume’s Attack on Science. Among the many traditional conceptions upon which Hume turned his critical examination, that of causation occupies the most of his attention. He discusses it both in the Treatise and in the Enquiry. He is the first philosopher since Aristotle to give it comprehensive treatment. He saw that all philosophical, theological, and indeed scientific knowledge rests upon this conception of causation. It was accepted without question by the Scholastics of the Middle Ages, the Rationalists of the Renaissance, and the scientists of his own time. If the conception is valid, Hume’s criticism goes for naught; for “by means of that relation we can go beyond the evidence of our memory and senses.” In that case what becomes of Hume’s psychological analysis that all knowledge consists of impressions and ideas? And if Hume’s psychology falls, all his criticism of the spiritual and the material substance falls also. Upon the validity of the concept of cause depend many of the scholastic arguments for the existence of God, whose existence we can demonstrate although He is not an object of sense impression. Imagination can then go on unrestricted; for God is accepted not only as cause, but as first or uncaused cause. Descartes, Leibnitz, and even Berkeley and Locke had accepted the causal argument for the existence of God, although the latter two had pretended to restrict knowledge to sense-perceptions and ideas. Again, the causal concept has been the foundation for the belief in a functioning soul behind the mental and physical activities of a human being; and on the same causal concept man has argued from sensations to their material substrate. All this is unwarranted and unrestricted knowledge because it “goes beyond the memory and senses.” Not only theology, but science itself has gone “beyond the memory and senses.” Hume dares to doubt the certainty of the causal principle even in scientific knowledge. Is there any necessary connection among events so that with certainty we can predict the occurrence of one event if another is given? Is there in nature and history any causal law so binding that every event is a necessary result of what has gone before and a necessary cause of what will come? The question of cause is, therefore, paramount with Hume. If he is successful in impeaching cause as he has been in the case of substance, scientific theory must fall with theological dogma.
In his review of the conceptions of time and space (association by contiguity), Hume had found succession to be a quality of impressions and to be given with them. But that is all that can be said—the relation is one of time order, but not a relation that is necessary. The outer impressions happen to occur thus and thus; they need not have occurred thus, and may never occur in this order again. This temporal order is not by any means a causal order. The idea of cause is that of power transferred, but we have no impression of power. Impressions come as sequences, not as consequences or as powers. Sequences of impressions are the only “matters of fact”; consequences are not “matters of fact.” They must, therefore, be only “relations between ideas” and have no objective reality. From Hume’s point of view this is sufficient to show that cause is not valid and real.
To deny that we have the concept of cause would, however, be nonsense. We do have the concept, and how is its psychological origin to be explained? How does the idea arise? It does not originate (1) as an a priori concept, i. e. by an analysis of ideas, nor (2) as an outer impression, i. e. a sensation, nor (3) as memory, since memories are images of impressions. The idea of cause originates from an inner impression—a strong and lively feeling connected with the imagination. But how does it happen that the feeling is so strong that it makes us believe the idea, with which it is connected, is a reality? The feeling does not arise from a single instance of conjunction of two impressions, but from the conjunction of two ideas repeated many times. The belief in cause is a feeling originating in the constant conjunction of impressions. This explains why the ideas that fire will burn, that poison will kill, that water will wet—are so lively. The conjunction occurs many times, and an inner necessity or compulsion arises to imagine the second impression after the first. Given the first idea, we learn to expect the second. Repetition produces nothing new in objects, but it produces in the mind a new feeling to pass from one idea to the idea usually attending it. Necessity exists in the mind and not in the objects.
The Extent and Limits of Human Knowledge. What remnants of knowledge remain after Hume has applied his destructive criticism? His critics would answer that, if Hume had been consistent, no knowledge whatever would remain. Upon the basis of pure positivism, that all knowledge is composed of impressions and their copies, knowledge is an impossibility. But he introduced an additional element, “relations,” that made knowledge possible because it afforded synthesis and allowed distinctions.
Taking Hume’s doctrine as it stands, his results are these. There are two classes of sciences, the formal and the empirical. The formal includes logic and mathematics, and consists of knowledge of relations between ideas. Such knowledge has certainty and validity. Empirical sciences consist in knowledge of matters of fact. Such knowledge never amounts to more than probability. There is no certainty or demonstration in natural science. Its results call forth not conviction, but belief. Beyond these subjects we have no knowledge whatever. Metaphysics and theology are only fictions. Beyond impressions and the copies of impressions we can make no assertions. The tendency of thought to trench beyond its own territory is the cause of all our metaphysical difficulties. It tries to do what it was not intended to do, and the result is abstract ideas. Reason and the relation of resemblance give us the erroneous idea of spiritual and material substance; imagination and the relation of cause give the erroneous idea of the fundamental principle of nature.
Hume’s Theory of Religion and Ethics. Hume is so true an empiricist to the end that he is a remarkable exception among the philosophers of the Enlightenment. He alone among philosophers shows the historical sense in the application of his positivism to religion and morals. In general the Enlightenment took no account of the past; in this Hume differs from his contemporaries.
Hume was the destroyer of deism because he advanced historical evidence against deism. Deism had three principles: that religion is the object of scientific investigation; that religion had its origin in the reason; and that “natural religion” is the oldest form. Hume agreed to the first proposition, but he revealed his historical instinct by showing that religion did not originate in the reason, but in the feelings; and that not “natural religion,” but idolatry, etc., is the oldest form. Furthermore, he stood almost alone among philosophers of the period in building ethics upon the feelings rather than upon the intellect. The ethical motives of man are pleasure and pain, and not an idea of the reason. Hume’s historic sense led him to this conclusion.
Both morals and religion should be empirically investigated. As in science, so in them the most cogent conclusions are only probable and not intuitive. Our moral activities are under the same kind of law of cause that exists in the world of nature-phenomena. The will is determined by the feelings, and the reason is the slave of the passions. Our moral judgment is based on the feeling of sympathy (Adam Smith). It is practically probable that there is a purpose in the world and therefore a God. But this cannot be established. On the same principle of probability the world may have grown up mechanically or by chance. Religion is naturally reasonable enough, but its doctrines cannot be proved.
The Scottish School. This school represents in Great Britain the reaction from the sensualism of the Enlightenment. The Scottish School was the British reply to Hume, just as Kant was the German reply. They were the late eighteenth century reactions in two countries to the Enlightenment. The teaching of Kant was, however, also the beginning of a new movement and a new period. The Scottish School has no such importance.
Thomas Reid (1710–1796) was the founder. Reid admitted that Berkeley and Hume drew legitimate conclusions from Locke’s general assumption that the objects of thought are not things, but ideas. Therefore Reid maintained that Locke’s position must be given up. Still empiricism remains tenable and must be applied to the phenomena of mind. What are the data of consciousness? Not individual ideas, as Locke said, but complex ideas or judgments. The elements will be discovered later by analysis of these complex states which are first given. The mind is not a blank piece of paper upon which simple characters are first inscribed, and then later the understanding introduced to form judgments and the reflection to add belief in the existence of objects. Our knowledge starts rather from judgments, which involve certain original truths or “natural judgments.” Mankind possesses the faculty of “common sense,” and this faculty makes these truths a common possession. Among the principles that “common sense” includes are self-consciousness, the reality of objects perceived, and the principle of cause.
The Scottish School called attention to the importance of self-observation. The members of the school made their attack upon sensualism from the point of empirical psychology. Philosophy became in their hands the perfecting of psychology as a science of inner observation. Thus they were in accord with the school of the Enlightenment, although opposed to its sensualistic outcome. The prominent members of the school were Reid, Dugald Stewart, Brown, and Sir William Hamilton.