As a philosopher Descartes has, to begin with, the merit of exemplary clearness. The fault is not with him if we cannot tell what he thought and how he came to think it. The classic Discourse on Method (1637) relates his mental history in a style of almost touching simplicity. It appears that from an early age truth had been his paramount object, not as with Bacon and Hobbes for its utility, but for its own sake. In search of this ideal he read widely, but without finding what he wanted. The great and famous works of literature might entertain or dazzle; they could not convince. The philosophers professed to teach truth; their endless disputes showed that they had not found it. Mathematics, on the other hand, presented a pleasing picture of demonstrated certainty, but a certainty that seemed to be prized only as a sure foundation for the mechanical arts. Wearily throwing his books aside, the young man then applied himself to the great book of life, mingling with all sorts and conditions of men to hear what they had to say about the prime interests of existence. But the same vanity and vexation of spirit followed him here. Men were no more agreed among themselves than were the authorities of his college days. The truths of religion seemed, indeed, to offer a safe refuge; but they were an exception that proved the rule; being, as Descartes observes, a supernatural revelation, not the natural knowledge that he wanted.
The conflict of authorities had at least one good result, which was to discredit the very notion of authority, thus throwing the inquirer back on his own reason as the sole remaining resource. And as mathematics seemed, so far, to be the only satisfactory science, the most reasonable course was to give a wider extension and application to the methods of algebra and geometry. Four fundamental rules were thus obtained: (1) To admit nothing as true that was not evidently so; (2) to analyse every problem into as many distinct questions as the nature of the subject required; (3) to ascend gradually from the simplest to the most complex subjects; and (4) to be sure that his enumerations and surveys were so exhaustive and complete as to let no essential element of the question escape.
The rules as they stand are ill-arranged, vague, and imperfect. The last should come first and the first last. The notions of simplicity, complexity, and truth are neither illustrated nor defined. And no pains are taken to discriminate judgments from concepts. It may be said that the method worked well; at least Descartes tells us that with the help of his rules he made rapid progress in the solution of mathematical problems. We may believe in his success without admitting that an inferior genius could have achieved the same results by the same means. The real point is to ascertain whether the method, whatever its utility in mathematics, could be advantageously applied to metaphysics. And the answer seems to be that as manipulated by its author the new system led to nothing but hopeless fallacies.
After reserving a provisional assent to the customs of the country where he happens to be residing and to the creed of the Roman Church, Descartes begins by calling in question the whole mass of beliefs he has hitherto accepted, including the reality of the external world. But the very act of doubt implies the existence of the doubter himself. I think, therefore I am. It has been supposed that the initial affirmation of this self-evident principle implies that Descartes identified Being with Thought. He did no such thing. No more is meant, to begin with, than that, whatever else is or is not, I the thinker certainly am. This is no great discovery; the interesting thing is to find out what it implies. A good deal according to Descartes. First he infers that, since the act of thinking assures him of his existence, therefore he is a substance the whole essence of which consists in thought, which is independent of place and of any material object—in short, an immaterial soul, entirely distinct from the body, easier to know, and capable of existing without it. Here the confusion of conception with judgment is apparent, and it leads to a confusion of our thoughts about reality with the realities themselves. And Descartes carries this loose reasoning a step further by going on to argue that, as the certainty of his own existence has no other guarantee than the clearness with which it is inferred from the fact of his thinking, it must therefore be a safe rule to conclude that whatever things we conceive very clearly and distinctly are all true.
In his other great philosophical work, the Meditations, Descartes sets out at greater length, but with less clearness, his arguments for the immateriality of the soul. Here it is fully admitted that, besides thinking, self-consciousness covers the functions of perceiving, feeling, desiring, and willing; nor does it seem to be pretended that these experiences are reducible to forms of thought. But it is claimed that they depend on thought in the sense that without thought one would not be aware of their existence; whereas it can easily be conceived without them. A little more introspection would show that the second part of the assertion is not true; for there is no thought without words, and no words, however inaudibly articulated, without a number of tactual and muscular sensations, nor even without a series of distinct volitions.
Another noticeable point is that, so far from obeying the methodical rule to proceed from the simple to the complex, Descartes does just the contrary. Starting with the whole complex content of consciousness, he works down by a series of arbitrary rejections to what, according to him, is the simple fact of immaterial thought. Let us see how it fares with his attempt to reconstruct knowledge on that elementary basis.
Returning to his postulate of universal doubt, our philosopher argues from this to an imperfection in his nature, and thence to the idea of a perfect being. The reasoning is most slipshod; for, even admitting that knowledge is preferable to ignorance—which has not been proved—it does not follow that the dogmatist is more perfect than the doubter. Indeed, one might infer the contrary from Descartes's having passed with progressive reflection from the one stage to the other. Overlooking the paralogism, let us grant that he has the idea of a perfect being, and go on to the question of how he came to possess it. One might suggest that the consciousness of perfect self-knowledge, combined with the wish to know more of other subjects, would be sufficient to create an ideal of omniscience, and, proceeding in like manner from a comparison of wants with their satisfactions, to enlarge this ideal into the notion of infinite perfection all round. Descartes, however, is not really out for truth—at least, not in metaphysics; he is out for a justification of what the Jesuits had taught him at La Flèche, and no Jesuit casuistry could be more sophistical than the logic he finds good enough for the purpose. To argue, as he does, that the idea of a perfect being, in his mind, can be explained only by its proceeding from such a being as its creator is already sufficiently audacious. But this feat is far surpassed by his famous ontological proof of Theism. A triangle, he tells us, need not necessarily exist; but, assuming there to be one, its three angles must be equal to two right angles. With God, on the other hand, to be conceived is to be; for, existence being a perfection, it follows, from the idea of a perfect Being, that he must exist. The answer is more clear and distinct than any of Descartes's demonstrations. Perfection is affirmed of existing or of imaginary subjects, but existence is not a perfection in itself.
A third argument for Theism remains to be considered. Descartes asks how he came to exist. Not by his own act; for on that hypothesis he would have given himself all the perfections that now he lacks; nor from any other imperfect cause, for that would be to repeat the difficulty, not to solve it. Besides, the simple continuance of his existence from moment to moment needs an explanation. For time consists of an infinity of parts, none depending in any way on the others; so that my having been a little while ago is no reason why I should be now, unless there is some power by which I am created anew. Here we must observe that Descartes is playing fast and loose with the law of causation. By what he calls the light of nature—in other words, the light of Greek philosophy—things can no more pass into nothing than they can come out of it. Moreover, the difficulty is the same for my supposed Creator as for myself. We are told that thought is a necessary perfection of the divine nature. But thinking implies time; therefore God also exists from moment to moment. How, then, can he recover his being any more than we can? The answer, of course, would be: because he is perfect, and perfection involves existence. Thus the argument from causation throws us back on the so-called ontological argument, whose futility has already been shown.
This very idea of perfection involves us in fresh difficulties with the law of causation. A perfect Being might be expected to make perfect creatures—which by hypothesis we are not. Descartes quite sees this, and only escapes by a verbal quibble. Our imperfections, he says, come from the share that Nothingness has in our nature. Once allow so much to the creative power of zero, and God seems to be a rather gratuitous postulate.
After proving to his own satisfaction the existence of the soul and of God, Descartes returns to the starting-point of his whole inquiry—that is, the reality of the material world and of its laws. And now his theology supplies him with a short and easy method for getting rid of the sceptical doubts that had troubled him at first. He has a clear and distinct idea of his own body and of other bodies surrounding it on all sides as extended substances communicating movements to one another. And he has a tendency to accept whatever is clearly and distinctly conceived by him as true. But to suppose that God created that tendency with the intention of deceiving him would argue a want of veracity in the divine nature incompatible with its perfection. Such reasoning obviously ignores the alternative that God might be deceiving us for our good. Or rather what we call truth might not be an insight into the nature of things in themselves, but a correct judgment of antecedents and consequents. Our consciousness would then be a vast sensori-motor machinery adjusted to secure the maintenance and perfection of life.
Descartes, as a mathematician, places the essence of Matter or Body in extension. Here he agrees with another mathematical philosopher, Plato, who says the same in his Timæus. So far the coincidence might be accidental; but when we find that the Frenchman, like the Greek, conceives his materialised space as being originally divided into triangular bodies, the evidence of unacknowledged borrowing seems irresistible—the more so that Huyghens mentions this as customary with Descartes.
The great author of the Method and the Meditations—for, after every critical deduction, his greatness as a thinker remains undoubted—contributed nothing to ethics. Here he is content to reaffirm the general conclusions of Greek philosophy, the necessary superiority of mind to matter, of the soul to the body, of spirit to sense. He accepts free-will from Aristotle without any attempt to reconcile it with the rigid determinism of his own mechanical naturalism. At the same time there is a remarkable anticipation of modern psychology in his doctrine of intellectual assent as an act of the will. When our judgments go beyond what is guaranteed by a clear and distinct perception of their truth there is a possibility of error, and then the error is our own fault, the precipitate conclusion having been a voluntary act. Thus human free-will intervenes to clear God of all responsibility for our delusions as well as for our crimes.
Malebranche.
Pascal, we are told, could not forgive Descartes for limiting God's action on the world to the "initial fillip" by which the process of evolution was started. Nevertheless, Pascal's friends, the Jansenists, were content to adopt Cartesianism as their religious philosophy, and his epigram certainly does not apply to the next distinguished Cartesian, Arnold Geulincx (1625-1669), a Fleming of Antwerp. Unfortunate in his life, this eminent teacher has of all original thinkers received the least credit for his services to metaphysics from posterity, being, outside a small circle of students, still utterly unknown to fame. Geulincx is the author of a theory called Occasionalism. Descartes had represented mind, which he identified with Thought, and matter, which he identified with Extension, as two antithetical substances with not a note in common. Nevertheless, he supposed that communications between them took place through a part of the brain called the pineal body. Geulincx cut through even this narrow isthmus, denying the possibility of any machinery for transmitting sensible images from the material world to our consciousness, or volitions from the mind to the limbs. How, then, were the facts to be explained? According to him, by the intervention of God. When the so-called organs of sense are acted on by vibrations from the external world, or when a particular movement is willed by the mind, the corresponding mental and material modifications are miraculously produced by the exercise of his omnipotence; and it is because these events occur on occasion of signals of which they are not the effects but the consequents that the theory has received the name of Occasionalism.
The theory, as Geulincx formulated it, seems at first sight simply grotesque; and from a religious point of view it has the additional drawback of making God the immediate executor of every crime committed by man. Nevertheless, it is merely the logical application of a principle subsequently admitted by profound thinkers of the most opposing schools—namely, that consciousness cannot produce or transmit energy, combined with the belief in a God who does not exist for nothing. Even past the middle of the nineteenth century many English and French naturalists were persuaded that animal species to the number of 300,000 represented as many distinct creative acts; and at least one astronomer, who was also a philosopher, declared that the ultimate atoms of matter, running up to an immeasurably higher figure, "bore the stamp of the manufactured article."
The capture of Cartesianism by theology was completed by Nicolas Malebranche (1638-1715). This accomplished writer and thinker, dedicated by physical infirmity to a contemplative life, entered the Oratory at an early age, and remained in it until his death. Coming across a copy of Descartes's Treatise on Man at twenty-six, he at once became a convert to the new philosophy, and devoted the next ten years to its exclusive study. At the end of that period he published his masterpiece, On the Investigation of Truth (De la Recherche de la Vérité, 1674), which at once won him an enormous reputation. It was followed by other works of less importance. The legend that Malebranche's end was hastened by an argument with Berkeley has been disproved.
Without acknowledging the obligation, Malebranche accepts the conclusions of Geulincx to the extent of denying the possibility of any communication between mind and matter. Indeed, he goes further, and denies that one portion of matter can act on another. But his real advance on Occasionalism lies in the question: How, then, can we know the laws of the material universe, or even that there is such a thing as matter at all? Once more God intervenes to solve the difficulty, but after a fashion much less crude than the miraculous apparatus of Geulincx. Introspection assures us that we are thinking things, and that our minds are stored with ideas, including the idea of God the all-perfect Being, and the idea of Extension with all the mathematical and physical truths logically deducible therefrom. We did not make this idea, therefore it comes from God, was in God's mind before it was in ours. Following Plotinus, Malebranche calls this idea intelligible Extension. It is the archetype of our material world. The same is true of all other clear and distinct ideas; they are, as Platonism teaches, of divine origin. But is it necessary to suppose that the ideal contents of each separate soul were placed in it at birth by the Creator? Surely the law of parsimony forbids. It is a simpler and easier explanation to suppose that the divine archetypal ideas alone exists, and that we apprehend them by a mystical communion with the divine consciousness; that, in short, we see all things in God. And in order to make this vision possible we must, as the Apostle says, live, move, and have our being in God. As a mathematician would say, God must be the locus, the place of souls.
There is unquestionably something grandiose about this theory, which, however, has the defect in orthodox opinion of logically leading to the Pantheism, held in abhorrence by Malebranche, of his greater contemporary Spinoza. And it is a suggestive circumstance that the very similar philosophy of the Eternal Consciousness held by our countryman T. H. Green has been shown by the criticism of Henry Sidgwick to exclude the personality of God.
Spinoza.
With the philosopher whom I have just named we come for the first time in modern history to a figure recalling in its sustained equality of intellectual and moral excellence the most heroic figures of Hellenic thought. Giordano Bruno we may, indeed, pronounce, like Lucan or Cranmer, "by his death approved," but his submission at Venice has to be set against his martyrdom at Rome; and if there is nothing very censurable in his career as a wandering teacher, there is also nothing worthy of any particular respect. Differences of environment and heredity may no doubt be invoked to account for the difference of character; and in the philosophy about to be considered the determining influence of such causes for the first time finds due recognition; but on the same principle our ethical judgments also are determined by the very constitution of things.
Baruch de Spinoza (1632-1677), born at Amsterdam, belonged to a family of Portuguese Jews, exiled on account of their Hebrew faith, in which also he was brought up. Soon after reaching manhood he fell away from the synagogue, preferring to share in the religious exercises of certain latitudinarian Christian sects. Spies were set to report his conversation, which soon supplied evidence of sufficiently heterodox opinions. A sentence of formal excommunication followed; but modern research has discredited the story of an attempt to assassinate him made by an emissary of the synagogue. After successfully resisting the claim of his sister and his brother-in-law to shut out the apostate from his share of the paternal inheritance, Spinoza surrendered the disputed property, but henceforth broke off all communication with his family. Subsequently he refused an offer of 2,000 florins, made by a wealthy friend and admirer, Simon de Vries, as also a proposal from the same friend to leave him his whole fortune, insisting that it should go to the legal heir, Simon's brother Isaac. The latter, on succeeding, wished to settle an annual pension of 500 florins on Spinoza, but the philosopher would accept no more than 300. Books were his only luxury, material wants being supplied by polishing glass lenses, an art in which he attained considerable proficiency. But it was an unhealthy occupation, and probably contributed to his death by consumption.
Democracy was then and long afterwards associated with fanaticism and intolerance rather than with free-thought in religion. The liberal party in Dutch politics was the aristocratic party. Spinoza sympathised with its leader, John de Witt; he wept bitter tears over the great statesman's murder; and only the urgent remonstrances of his friends, who knew what danger would be incurred by such a step, prevented him from placarding the walls of the Hague, where he then resided, with an address reproaching the infuriated people for their crime.
In 1673 the enlightened ruler of the Palatinate, a brother of Descartes's Princess Elizabeth, offered Spinoza a professorship at Heidelberg, with full liberty to teach his philosophy. But the pantheistic recluse wisely refused it. Even at the present day such teaching as his would meet with little mercy at Berlin, Cambridge, or Edinburgh. As it was, we have reason to believe that even in free Holland only a premature death saved him from a prosecution for blasphemy, and his great work the Ethica could not with safety be published during his lifetime. It appeared anonymously among his posthumous works in November, 1677, without the name of the true place of publication on the title-page.
Spinoza was for his time no less daring as a Biblical critic than as a metaphysician. His celebrated Tractatus Theologico-Politicus has for its primary purpose to vindicate the freedom of scientific thought against ecclesiastical interference. And this he does by drawing a trenchant line of demarcation between the respective offices of religion and of philosophy. The business of the one is to form the character and to purify the heart, of the other to guide and inform the intellect. When religion undertakes to teach scientific truth the very ends for which it exists are defeated. When theological dogmatism gains control of the Churches the worst passions are developed under its influence. Instead of becoming lowly and charitable, men become disturbers of public order, grasping intriguers, bitter and censorious persecutors. The claims of theology to dictate our intellectual beliefs are not only mischievous, but totally invalid. They rest on the authority of the Bible as a revelation of God's will. But no such supernatural revelation ever was or could be given. Such violation of the order of nature as the miracles recorded in Scripture history would be impossible. And the narratives recording them are discredited by the criticism which shows that various books of the Old Testament were not written by the men whose names they bear, but long after their time. As a Hebrew scholar Spinoza discusses the Jewish Scriptures in some detail, showing in particular that the Pentateuch is of a later date than Moses. His limited knowledge of Greek is offered as a reason for not handling the New Testament with equal freedom; but some contradictions are indicated as disallowing the infallibility claimed for it. At the same time the perfection of Christ's character is fully acknowledged and accepted as a moral revelation of God.
Spinoza shared to the fullest extent, and even went beyond, Descartes's ambition to reconstruct philosophy on a mathematical basis. The idea may have come to him from the French thinker, but it is actually of much older origin, being derived from Plato, the leading spirit of the Renaissance, as Aristotle had been the oracle of the later Middle Ages. Now Plato's ideal had been to construct a philosophy transcending the assumptions—or, as he calls them, the hypotheses—of geometry as much as those assumptions transcend the demonstrations of geometry; and this also was the ideal of Spinoza. Descartes had been content to accept from tradition his ultimate realities, Thought, Extension, and God, without showing that they must necessarily exist; for his proof of God's existence starts from an idea in the human mind, while Thought and Extension are not deduced at all.
To appreciate the work of the Hebrew philosopher, of the lonely muser, bred in the religion of Jahveh—a name traditionally interpreted as the very expression of absolute self-existence—we must conceive him as starting with a question deeper even than the Cartesian doubt, asking not How can I know what is? but Why should there be anything whatever? And the answer, divested of scholastic terminology, is: Because it is inconceivable that there should be nothing, and if there is anything there must be everything. This universe of things, which must also be everlasting, Spinoza calls God.
The philosophy or religion—for it is both—which identifies God with the totality of existence was of long standing in Greece, and had been elaborated in systematic detail by the Stoics. It has been known for the last two centuries under the name of Pantheism, a word of Greek etymology, but not a creation of the Greeks themselves, and, indeed, of more modern date than Spinoza. Historians always speak of him as a Pantheist, and there is no reason to think that he would have objected to the designation had it been current during his lifetime. But there are important points of distinction between him and those who preceded or followed him in the same speculative direction. The Stoics differed from him in being materialists. To them reality and corporeality were convertible terms. It seems likely that Hobbes and his contemporary, the atomist Gassendi, were of the same opinion, although they did not say it in so many words. But Descartes was a strong spiritualist; and Spinoza followed the master's lead so far, at any rate, as to give Thought at least equal reality with matter, which he also identified with Extension. It has been seen what difficulties were created by the radical Cartesian antithesis between Thought and Extension, or—to call them by their more familiar names—mind and body, when taken together with the intimate association shown by experience to obtain between them; and also how Geulincx and Malebranche were led on by the very spirit of philosophy itself almost to submerge the two disparate substances in the all-absorbing agency of God. The obvious course, then, for Spinoza, being unfettered by the obligations of any Christian creed, was to take the last remaining step, to resolve the dualism of Thought and Extension into the unity of the divine substance.
In fact, the Hebrew philosopher does this, declaring boldly that Thought and Extension are one and the same thing—which thing is God, the only true reality of which they are merely appearances. And, so far, he has had many followers who strive to harmonise the opposition of what we now call subject and object in the synthesis of the All-One. But he goes beyond this, expanding the conception of God—or the Absolute—to a degree undreamed of by any religion or philosophy formulated before or after his time. God, Spinoza tells us, is "a Substance consisting of infinite attributes, each of which expresses his absolute and eternal essence." But of these attributes two alone, Thought and Extension, are known to us at present, so that our ignorance infinitely exceeds our knowledge of reality. His extant writings do not explain by what process he mounted to this, the most dizzy height of speculation ever attained by man; but, in the absence of definite information, some guiding considerations suggest themselves as probable.
Bruno, whom Spinoza is held, on strong grounds, to have read, identified God with the supreme unifying principle of a universe extending through infinite space. Descartes, on the other hand, conceived God as a thinking rather than as an extended substance. But his school tended, as we saw, to conceive God as mediating between mind and body in a way that suggested their real union through his power. Furthermore, the habit common to all Cartesians of regarding geometrical reasoning as the most perfect form of thought inevitably led to the conception of thought as accompanying space wherever it went—in fact, as stretching like it to infinity. Again, from the Cartesian point of view, that Extension which is the very essence of the material world, while it covers space, is more than mere space; it includes not only co-existence, but succession or time—that is, scientifically speaking, the eternal sequence of physical causes; or, theologically speaking, the creative activity of God. And reason or thought had also since Aristotle been more or less identified with the law of universal causation no less than with the laws of geometry.
Thus, then, the ground was prepared for Spinoza, as a pantheistic monist, to conceive God under the two attributes of Extension and Thought, each in its own way disclosing his essence as no other than infinite Power. But why should God have, or consist of, two attributes and no more? There is a good reason why we should know only those two. It is that we are ourselves modes of Thought united to modes of Extension, of which our thoughts are the revealing ideas. But it would be gross anthropomorphism to impose the limitations of our knowledge on the infinite being of God, manifested through those very attributes as unlimited Power. The infinite of co-existence, which is space, the infinite of causal procession, which is time, suggest an infinity of unimaginable but not inconceivable attributes of which the one divine substance consists. And here at last we get the explanation of why there should be such things as Thought and Extension at all. They are there simply because everything is. If I grant anything—and I must, at least, grant myself—I grant existence, which, having nothing outside itself, must fill up all the possibilities of being which only exclude the self-contradictory from their domain. Thus, the philosophy of Spinoza neither obliges him to believe in the monsters of mythology nor in the miracles of Scripture, nor in the dogmas of Catholic theology, nor even in free-will; nor, again, would it oblige him to reject by anticipation the marvels of modern science. For, according to him, the impossibility of really incredible things could be deduced with the certainty of mathematical demonstration from the law of contradiction itself.
Hegel has given the name of acosmism, or negation of the world, to this form of pantheism, interpreting it as a doctrine that absorbs all concrete reality and individuality in the absolute unity of the divine essence. No misconception could be more complete. Differentiation is the very soul of Spinoza's system. It is, indeed, more open to the charge of excessive dispersion than of excessive centralisation. Power, which is God's essence, means no more than the realisation through all eternity of all possibilities of existence, with no end or aim but just the process of infinite production itself. There is, indeed, a nominal identification between the material processes of Extension and the ideal processes of Thought. But this amounts to no more than a re-statement in abstract terms of the empirical truth that there is a close connection between body and mind. Like the double-aspect theory, the parallelistic theory, the materialistic theory, the theory of interaction, and the theory of more or less complete reciprocal independence, it is a mere verbalism, telling us nothing that we did not know before. Or, if there is more, it consists of the very questionable assumption that body and mind must come in somewhere to fill up what would otherwise be blank possibilities of existence. And this, like other metaphysical assumptions, is an illegitimate generalisation from experience. The ideas of space and time as filled-up continua supply the model on which the whole universe must be constructed. Like them, it must be infinite and eternal, but, so to speak, at a higher power; as in them, every part must be determined by the position of all other parts, with the determination put at a logical instead of at a descriptive value; corresponding to their infinitely varied differentiation of position and quantity, there must be an infinite differentiation of concrete content; and, finally, the laws of the universe must be demonstrable by the same à priori mathematical method that has been so successfully applied to continuous quantity.
The geometrical form into which Spinoza has thrown his philosophy unfortunately restricts the number of readers—always rather small—that it might otherwise attract. People feel themselves mystified, wearied, and cheated by the appearance, without the reality, of logical demonstration; and the repulsion is aggravated by the barbarous scholasticism with which—unlike Bacon, Hobbes, and Descartes—he peppers his pages. Yet, like the Greek philosophers, he is much more modern, more on the true line of developing thought than they are. But to get at the true kernel of his teaching we must, like Goethe, disregard the logical husks in which it is wrapped up. And, as it happens, Spinoza has greatly facilitated this operation by printing his most interesting and suggestive discussions in the form of Scholia, Explanations, and Appendices. Even these are not easy reading; but, to quote his own pathetic words, "If the way of salvation lay ready to hand, and could be found without great toil, would it be neglected by nearly everyone? But all glorious things are as difficult as they are rare."
Some of his expositors have called Spinoza a mystic; and his philosophy has been traced, in part at least, to the mystical pantheism of certain medieval Jews. In my opinion this is a mistake; and I will now proceed to show that the phrases on which it rests are open to an interpretation more consistent with the rational foundations of the whole system.
The things that have done most to fasten the character of a mystic on Spinoza are his identification of virtue with the knowledge and love of God, and his theory—so suggestive of Christian theology at its highest flight—that God loves himself with an infinite love. That, like Plato and Matthew Arnold, he should value religion as a means of popular moralisation might seem natural enough; but not, except from a mystical motive, that he should apparently value morality merely as a help to the religious life. On examination, however, it appears that the beatific vision of this pantheist offers no experience going beyond the limits of nature and reason. Since God and the universe are one, to know God is to know that we are, body and soul, necessary modes of the two attributes, Extension and Thought, by which the infinite Power which is the essence of the universe expresses itself for us. To love God is to recognise our own vitality as a portion of that power, welcoming it with grateful joy as a gift from the universe whence we come. And to say that God loves himself with an infinite love is merely to say that the attribute of Thought eternally divides itself among an infinity of thinking beings, through whose activity the universe keeps up a delighted consciousness of itself.
Spinoza declares by the very name of his great work that for him the philosophical problem is essentially a problem of ethics, being, indeed, no other than the old question, first started by Plato, how to reconcile disinterestedness with self-interest; and his metaphysical system is really an elaborate mechanism for proving that, on the profoundest interpretation, their claims coincide. His great contemporary, Hobbes, had taught that the fundamental impulse of human nature is the will for power; and Spinoza accepts this idea to the fullest extent in proclaiming Power to be the very stuff of which we and all other things are made. But he parts company with the English philosopher in his theory of what it means. On his view it is an utter illusion to suppose that to gratify such passions as pride, avarice, vanity, and lust is to acquire or exercise power. For strength means freedom, self-determination; and no man can be free whose happiness depends on a fortuitous combination of external circumstances, or on the consent of other persons whose desires are such as to set up a conflict between his gratification and theirs. Real power means self-realisation, the exercise of that faculty which is most purely human—that is to say, of Thought under the form of reason.
In pleading for the subordination of the self-seeking desires to reason Spinoza repeats the lessons of moral philosophy in all ages and countries since its first independent constitution. In connecting the interests of morality with the interests of science as such, he follows the tradition of Athenian thought. In interpreting pantheism as an ethical enthusiasm of the universe he returns to the creed of Stoicism, and strikes the keynote of Wordsworth's loftiest poetry. In fixing each man's place in nature as one among the infinite individuations of divine power he repeats another Stoic idea—with this difference, however, that among the Stoics it was intimately associated with their teleology, with the doctrine that everything in nature has a function without whose performance the universe would not be complete; whereas Spinoza, following Bacon and Descartes, utterly abjures final causes as an anthropomorphism, an intrusion of human interests into a universe whose sole perfection is to exhaust the possibilities of existence. And herein lies his justification of evil which the Stoics could only defend on aesthetic grounds as enhancing the beauty of moral heroism by contrast and conflict. "If I am asked," he says, "why God did not create all men of such a character as to be guided by reason alone, my answer is because he had materials enough to create all things from the highest to the lowest degree of perfection." Perfection with him meaning reality, this account of evil—and of error also—points to the theory of degrees of reality, revived and elaborated in our own time by Mr. F. H. Bradley, involving a correlative theory of illusion. Now, the idea of illusion, although older than Plato, was first applied on a great scale in Plato's philosophy, of whose influence on seventeenth-century thought this is not the only example. We shall find it to some extent countervailed by a revived Aristotelian current in the work of the metaphysician who now remains to be considered.
Leibniz.
G. W. Leibniz (1646-1716), son of a professor at the University of Leipzig, is marked by some of the distinguishing intellectual characters of the German genius. Far more truly than Francis Bacon, this man took all knowledge for his province. At once a mathematician, a physicist, a historian, a metaphysician, and a diplomatist, he went to the bottom of whatever subject he touched, and enriched all his multifarious studies with new views or with new facts. And as with other great countrymen of his, the final end of all this curiosity and interest was to combine and reconcile. One of his ambitions was to create a universal language of philosophy, by whose means its problems were to be made a matter of mathematical demonstration; another to harmonise ancient with modern speculation; a third—the most chimerical of all—to compose the differences between Rome and Protestantism; a fourth—partly realised long after his time—to unite the German Calvinists with the Lutherans. In politics he tried, with equal unsuccess, to build up a Confederation of the Rhine as a barrier against Louis XIV., and to divert the ambition of Louis himself from encroachments on his neighbours to the conquest of Egypt.
It seems probable that no intellect of equal power was ever applied in modern times to the service of philosophy. And this power is demonstrated, not, as with other metaphysicians, by constructions of more or less contestable value, however dazzling the ingenuity they may display, but by contributions of the first order to positive science. It is now agreed that Leibniz discovered the differential calculus independently of Newton; and, what is more, that the formulation by which alone it has been made available for fruitful application was his exclusive invention. In physics he is a pioneer of the conservation of energy. In geology he starts the theory that our planet began as a glowing molten mass derived from the sun; and the modern theory of evolution is a special application of his theory of development.
Intellect alone, however, does not make a great philosopher; character also is required; and Leibniz's character was quite unworthy of his genius. Ambitious and avaricious, a courtier and a time-server, he neither made truth for its own sake a paramount object, nor would he keep on terms with those who cherished a nobler ideal. After cultivating Spinoza's acquaintance, he joined in the cry of obloquy raised after his death, and was mean enough to stir up religious prejudice against Newton's theory of gravitation. Of the calamity that embittered his closing days we may say with confidence that it could not possibly have befallen Spinoza. On the accession of the Elector of Hanover to the English crown as George I., Leibniz sought for an invitation to the Court of St. James. Apparently the prince had not found him very satisfactory as a State official, and had reason to believe that Leibniz would have liked to exchange his office of historiographer at Hanover for a better appointment at Vienna. Greatness in other departments could not recommend one whom he knew only as a negligent and perhaps unfaithful servant to the favour of such an illiterate master. Anyhow, the English appointment was withheld, and the worn-out encyclopædist succumbed to disease and vexation combined. The only mourner at his funeral was his secretary, Eckhardt, who hastened to solicit the reversion of the offices left vacant by his chief's decease.
A single theory of Leibniz has attained more celebrity than any one utterance of any other philosopher; but that fame is due to the undying fire in which it has been enveloped by the mocking irony of Voltaire. Everything is for the best in the best of all possible worlds. Such is the famous text as a satire on which Candide was composed. Yet whatever value Voltaire's objections to optimism may possess tells nearly as much against Voltaire himself as against his unfortunate butt. For, after all, believing as he did in a God who combined omnipotence with perfect goodness he could not any more than Leibniz evade the obligation of reconciling the divine character with the divine work. On à priori grounds the German philosopher seems to have an incontrovertible case. A perfect Being must have made the best possible world. The only question is what we mean by goodness and by possibility. Spinoza had solved the problem by identifying goodness with existence. It is enough that the things we call evil are possible; the infinite Power of nature would be a self-contradiction were they not realised. Leibniz rejects the pantheistic position in terms, but nearly admits it in practice. Evil for him means imperfection, and if God made a world at all it was bound to be imperfect. The next step was to call pain an imperfection, which suggests a serious logical deficiency in the optimist; for, although in certain circumstances the production of pain argues imperfection in the operator, we are not entitled to argue that wherever there is pain there must be imperfection. Another plea is the necessity of pain as a punishment for crime, or, more generally, as a result of moral freedom. Such an argument is only open to the believers in free-will. A world of free and responsible agents, they urge, is infinitely more valuable than a world of automata; and it is not too dearly purchased even at the cost of such suffering as we witness. The argument is not very convincing; for liberty of choice in a painless world is quite conceivable. But, be it a good or bad argument, although it might appeal to Voltaire, who believed in free-will, it could not decently be used by Leibniz, who was a determinist of the strictest type. To make this clear we must now turn to his metaphysical system.
Bacon, Descartes, and Spinoza, disagreeing widely on other subjects, were agreed in discountenancing the study of final causes: Bacon, apparently, from dislike of the idea that the perfect adaptation of all things to the service of man rendered superfluous any efforts to make them more serviceable still; Descartes from his devotion to the mathematical method which was more applicable to a system of mechanical causation; Spinoza for the same reason, and also from his disbelief in a personal God. Leibniz, on the contrary, felt deeply impressed by a famous passage in Plato's Phædo, where Socrates, opposing the philosophy of teleology to the philosophy of mechanism, desiderates an explanation of nature as designed with a view to the highest good. But Leibniz did not go so far as Plato. Mediating between the two methods, he taught that all is done for the best, but also that all is done through an unbroken series of efficient causes. At the same time, these causes are only material in appearance; in reality they are spiritual beings. There is no such thing as dead matter; the universe consists of living forces all through. The general idea of force probably came from that infinite Power of which, according to Spinoza, the whole universe is at once the product and the expression; or it may have been suggested by Plato's incidental identification of Being with Action. But Leibniz found his type of force in human personality, which, following the lead of Aristotle rather than of Plato, he conceived as an Entelechy, or realised Actuality, and a First Substance. After years of anxious reflection he chose the far happier name of Monad, a term originally coined by Bruno, but not, as would appear, directly borrowed from him by the German metaphysician.
According to Leibniz, the monads or ultimate elements of existence are constituted by the two essential properties of psychic life, perception and appetency. In this connection two points have to be made clear. What he calls bare monads—i.e., the components of what is known as inorganic matter—although percipient, are not conscious of their perceptions; in his language they do not apperceive. And he endeavours to prove that such a mentality is possible by a reference to our own experience. We hear the roaring of waves on the seashore, but we do not hear the sound made by the falling of each particle of water. And yet we certainly must perceive it in some way or other, since the total volume of sound is made up of those inaudible impacts. He overlooks the conceivable alternative that the immediate antecedent of our auditory sensations is a cerebral disturbance, and that this must attain a certain volume in order to produce an effect on our consciousness. The other point is that the appetency of a monad does not mean an active impulse, but a search for more and more perceptions, a continuous widening of its cognitive range. In short, each monad is a little Leibniz for ever increasing the sum of its knowledge.
At no stage does that knowledge come from experience. The monad has no windows, no communication of any kind with the external world. But each reflects the whole universe, knowing what it knows by mere introspection. And each reflects all the others at a different angle, the angles varying from one another by infinitesimal degrees, so that in their totality they form a continuous series of differentiated individuals. And the same law of infinitesimal differentiation is observed by the series of progressive changes through which the monads are ever passing, so that they keep exact step, the continuity of existence being unbroken in the order of succession as in the order of co-existence. Evidently there is no place for free-will in such a system; and that Leibniz, with his relentless fatalism, should not only admit the eternal punishment of predestined sinners, but even defend it as morally appropriate, obliges us to condemn his theology as utterly irrational or utterly insincere.
In this system animal and human souls are conceived as monads of superior rank occupying a central and commanding position among a multitude of inferior monads constituting what we call their bodies, and changing pari passu with them, the correspondence of their respective states being, according to Leibniz, of such a peculiarly intimate character that the phenomena of sensation and volition seem to result from a causal reaction instead of from a mechanical adjustment such as we can imagine to exist between two clocks so constructed and set as to strike the same hour at the same time. This theory of the relations between body and soul is known to philosophy as the system of pre-established harmony.
It may be asked how every monad can possibly reflect every other monad when we do not know what is passing in our own bodies, still less what is passing all over the universe. The answer consists in a convenient distinction between clear and confused perceptions, the one constituting our actual and the other our potential knowledge. A more difficult problem is to explain how any particular monad—Leibniz or another—can consistently be a monadologist rather than a solipsist believing only in its own existence. Here, as usual, the Deus ex Machina comes in. Following Descartes, I think of God as a perfect Being whose idea involves his existence, with, of course, the power, will, and wisdom to create the best possible world—a universe of monads—which, again, by its perfect mutual adjustments, proves that there is a God. A more serious, and indeed absolutely insuperable, objection arises from the definition of the monads as nothing but mutually reflecting entities. For even an infinity of little mirrors with nothing but each other to reflect must at once collapse into absolute vacuity. And with their disappearance their creator also disappears. God, the supreme monad, we are told, has only clear perceptions; but the clearness is of no avail when he has nothing to perceive but an absolute blank. Leibniz rejected the objectivity of time and space; yet the hollow infinity of those blank forms seems, in his philosophy, to have reached the consciousness of itself.
Locke, Berkeley, Hume, Kant.
Epistemology, or theory of knowledge, did not begin in modern times. Among the Greeks it goes back, at least, to Empedocles, and figures largely in the programmes of the later schools. And Descartes's universal doubt seems to give the question, How can we be sure of anything? a foremost place in speculation. But the singular assurance with which the Cartesian metaphysicians presented their adventurous hypotheses as demonstrated certainties showed that with them the test of truth meant whatever told for that which, on other grounds, they believed to be true. In reality, the thing they called reason was hardly more than a covert appeal to authority, a suggestion that the duty of philosophy was to reconcile old beliefs with new. And the last great dogmatist, Leibniz, was the one who practised this method of uncritical assumption to the utmost extent.
Locke.
It is the peculiar glory of John Locke (1632-1704) to have resumed that method of doubt which Descartes had attempted, but which his dogmatic prepossessions had falsified almost at the first start. This illustrious thinker is memorable not only for his services to speculation, but for the example of a genuinely philosophic life entirely devoted to truth and good—a character in which personal sweetness, simplicity, and charm were combined with strenuous, disinterested, and fearless devotion to the service of the State. Locke was a Whig when Whiggism meant advanced Liberalism in religion and politics, and when that often meant a choice between exile and death. Thus, after the fall of his patron, Lord Shaftesbury, the philosopher had to take refuge in Holland, remaining there for some years, lying hid even there for some time to escape an extradition order for which the Government of James II. had applied. It was in Holland that he wrote the Essay Concerning Human Understanding.
This revolutionist in thought was no solitary recluse, but, in the best sense, a thorough man of the world. Educated at Westminster and Christ Church, he had, in the German poet's phrase, the supreme happiness of combining the seriousness of an enthusiast with the sagacity of a statesman, so that great statesmen recognised him as one of themselves. With the triumph of the Whig cause at a time when diplomacy demanded the utmost tact and skill, it was proposed to send Locke as Ambassador to the Court of Brandenburg, and, as that would not have suited his sober habits, to the Court of Vienna. Weak health obliging him to decline this also, he received office in the Ministry at home, taking a department where business talents were eminently required. In that capacity he bore a leading part in the restoration of the coinage, besides inspiring the Toleration Act and the Act for Unlicensed Printing. Even the wisest men make mistakes; and it must be noticed with regret that Locke's theory of toleration excluded Roman Catholics on the one side and atheists on the other—the former because their creed made persecution a duty, the latter because their want of a creed left them no sanction for any duties whatever. To say that Locke had not our experience does not excuse him, for in both cases the expediency of toleration can be proved à priori. Romanists must be expected to suppress a heresy whose spokesman declares that when he has the power he will suppress their Church; and, if atheists are without moral principle, they will propagate, under cover of orthodoxy, negations that they are not allowed openly to profess.
Locke was brought up by a Puritan father; and, although in after life he wandered far from its doctrinal standards, he no doubt always retained a sense of that close connection between religion and morality which Puritanism implies. Telling about the train of thought that started his great Essay, he refers it to a conversation between himself and some friends, in which they "found themselves quickly at a stand by the difficulties that rose on every side;" and, according to an intimate friend of his, the discussion turned "on the principles of morality and revealed religion." It then occurred to him that they should first ascertain "what objects their understandings were or were not fitted to deal with." And the mottoes prefixed to the essay prove that the results were of a decidedly sceptical cast. Indeed, his successors, though not himself, were destined to develop them into what is now called Agnosticism.
We have further to note that, while his Continental rivals were mathematicians, our English philosopher never went deeply into mathematics, but was by calling a physician. In this he resembles Aristotle and Sextus Empiricus among the Greeks; and so it is quite in order that, with the same sort of training, he should adopt Aristotle's method of experience as against Platonic transcendentalism, and the sceptical relativism of Sextus as against the dogmatism of the schools.
Locke begins his essay with a vigorous polemic against the doctrine of Innate Ideas. The word "idea," as he uses it, is ambiguous, serving to denote perceptions, notions, and propositions; but this confusion is of no practical importance, his object being to show that all our knowledge originates in experience; whereas the reigning belief was that at least the first principles of knowledge had a more authoritative, if not a mystical, source. Hobbes had been beforehand with him in deriving every kind of knowledge from experience, but had been content to assume his case; whereas Locke supports his by a formidable array of proofs. The gist of his argument is that intellectual and moral principles supposed to be recognised by all mankind from their infancy are admitted only by some, and by those only as the result of teaching.
As we saw, the whole inquiry began with questions about religion and morality; and it is precisely in reference to the alleged universality and innateness of the belief in God and the moral law that Locke is most successful. And the more modern anthropology teaches us about primitive man, the stronger becomes the case against the transcendental side in the controversy. Where his analysis breaks down is in dealing with the difficult and important ideas of Space, Time, Substance, and Causality—with the fatal result that such questions as, How is experience itself possible? or, How from a partial experience can we draw universal and necessary conclusions? find no place in his theory of knowledge. Of course, his contemporaries are open to the same criticism—nor, indeed, had the time come even for the statement of such problems. Meanwhile, the facility with which the founder of epistemology accepts fallacies whence Spinoza had already found his way out shows how little he was master of his means. According to Locke, it is "a certain and evident truth that there is an eternal, most powerful, and most knowing being, which whether anyone will please to call God it matters not." On examination the proof appears to involve two unproved assumptions. The first is that nothing can begin to exist without a cause. The second is that effects must resemble their causes. And from these it is inferred that an all-powerful being must have existed from all eternity. The alternative is overlooked that a succession of more limited beings would answer the purpose equally well, while it would also be more consistent with our experience. But a far more fatal objection to Locke's theism results from his second assumption. This, although not explicitly stated, is involved in the assertion that for knowledge such as we possess to originate from things without knowledge is impossible. For, on the same principle, matter must have been made by something material, pain by something that is pained, and evil by something that is evil. It would not even be going too far to say that by this logic I myself must have existed from all eternity; for to say that I was created by a not-myself would be to say that something may come from nothing.
We have seen how Locke refused toleration to atheists on the ground that their denial of a divine lawgiver and judge destroys the basis of morality. He did not, like Spinoza, believe that morality is of the nature of things. For him it is constituted by the will of God. Possibly, if pressed, he might have explained that what atheism denies is not the rule of right, but the sanction of that rule, the fear of supernatural retribution. Yet being, like Spinoza and Leibniz, a determinist, he should have seen that a creator who sets in motion the train of causes and effects necessarily resulting in what we call good or bad human actions has the same responsibility for those actions as if he had committed them himself. To reward one of his passive agents and to punish another would be grossly unjust and at the same time perfectly useless. But how do we know that he will, on any theory of volition, reward the good and punish the bad? "Because we have his word for it." And how do we know that he will keep his word? "Because he is all-good." But that, on Locke's principles, is pure assumption; and God, being quite sure that he has no retribution to fear, must be even more irresponsible than the atheist.
The principle that nothing can come from nothing, so far from proving theism, leads logically either to pantheism or to a much more thorough monadism than the system of Leibniz. And, metaphysics apart, it conflicts with a leading doctrine of the essay—that is the fundamental distinction between the primary and the secondary qualities of matter. We think of bodies as in themselves extended, resisting and mobile, but not in themselves as coloured, sonorous, odorous, hot, cold, or sapid. They cause our special sensations, but cause them by an unknown power. Again we perceive—or think we perceive—both primary and secondary qualities in close union as properties of a single object, and this object in which they jointly inhere is called a substance. And to the question, What is substance? Locke admits that he has no answer except something we know not what. He has returned to the agnostic standpoint of the Cyrenaic school. This something, for aught we know, might have created the world.
Continental historians regard the whole rationalistic movement of the eighteenth century, or what in Germany is called the Enlightenment (Aufklärung), as having been started by Locke. But the sort of arguments that he adduces for the existence of a God prove that in theology at least his rationalism had rather narrow limits. Both his theism and his acceptance of Christianity on the evidence of prophecy and miracles show no advance on medieval logic. In this respect Spinoza and Bayle (1622-1709) were far more in line with the modern movement. Still, assuming scripture as an authoritative revelation, Locke shows that, rationally interpreted, it yields much less support to dogmatic orthodoxy than English Churchmen supposed. And whatever may have been the letter of his religious teaching, there can be little doubt that the English Deists, Toland, Shaftesbury, and Anthony Collins, represented its true spirit more faithfully than the philosopher himself.
Representative government and the subordination of ecclesiastical to secular authority—or, better still, their separation—are both good things in themselves and favourable conditions to the life of reason. Another condition is that children should be trained to exercise their intelligence instead of relying blindly on authority. In these respects also Locke's writings acted powerfully on the public opinion of the next century, especially through the agency of French writers; France, as Macaulay justly claims, being the interpreter between England and the world. Our present business, however, is not with the diffusion but the development of thought, and to trace this we must return to British philosophy.
Berkeley.
George Berkeley (1684-1753) was born and educated in Ireland. The fact is of no racial or national importance, but interests us as accounting for his having received a better training in philosophy than at that time was possible in England. For the study of Locke, then proscribed at Oxford, had already been introduced into Dublin when Berkeley was an undergraduate there; and it was as a critical advance on Locke that his first publication, the New Theory of Vision (1709), was offered. Next year came the epoch-making Principles of Human Knowledge, followed in 1713 by the more popular Dialogues. At twenty-nine his work was done, and although he lived forty years longer, rising to be a Bishop in the Irish Church, after projecting a Christian Utopia for the civilisation of the North American Indians that never came to anything, and practising "every virtue under heaven," he made no other permanent contribution to thought.
Berkeley is at once a theorist of knowledge and a metaphysician, combining, in a way, the method of Locke with the method of Descartes and his successors. The popular notion of his philosophy is that it resolved the external world into a dream, or at least into something that has no existence outside our minds. But this is an utter misconception, against which Berkeley constantly protested. His quarrel was not with common sense, but with the theorists of perception. To understand this we must return for a moment to Locke's teaching. It will be remembered in what a tangle of difficulties the essay had left its author. Matter had two sets of qualities, primary and secondary, the one belonging to things in themselves, the other existing only in our minds; yet both somehow combined in real substances independent of us, but acting on our senses. Substance as such is an unknown and unknowable postulate; nevertheless, we know that it was created by God, of whom our knowledge is, if anything, inconveniently extensive. Now Berkeley, to find his way out of these perplexities, begins by attacking the distinction between primary and secondary qualities. For this purpose his Theory of Vision was written. It proves—or attempts to prove—that extension is not a real attribute of things in themselves, but an intellectual construction, or what Locke would have called an "idea of reflection." Till then people had thought that its objectivity was firmly established by the concurrent testimony of two senses, sight and touch. Berkeley shows, on the contrary, that visible and tangible extension are not the same thing, that the sensations—or, as he calls them, the ideas—of sight and touch are two different languages whose words we learn by experience to interpret in terms of each other without their being necessarily connected. A man born blind would not at first sight know how to interpret the visual signs of distance, direction, and magnitude; he would have to learn them by experience. These, in fact, are ideal relations only existing in the mind; and so we have no right to oppose mind as inextended to an extended or an external world.
Having thus cleared the ground, our young idealist proceeds in his next and greatest work, Of the Principles of Human Knowledge, to attack the problem from another side. The world of objects revealed through sensation and reflection is clearly no illusion, no creation of our own. We find it there, changing, when it changes, without or even very much against our will. What, then, is its origin and nature? Locke's view, which is the common view, tells us that it consists of material bodies, some animated and some not. And matter, the supposed substance of body, is made known to us by impressions on our organs of sense. But when we try to think of matter apart from these sensible qualities and the relations between them it vanishes into an empty abstraction. Now, according to Berkeley there are no abstract ideas—i.e., no thoughts unassociated with some mental image besides a mere word; and Matter or inanimate substance would be such an idea, therefore it does not exist. There is nothing but mind and its contents—what we call states of consciousness, what Locke and Berkeley called ideas. Whence, then, come the objects of our consciousness, and whither do they go when we cease to perceive them? At this point the new metaphysical system intervenes. Berkeley says that all things subsist in the consciousness of God, and by their subsistence his existence is proved. The direct apprehension of a reality that is not ourselves only becomes possible through what would be called in modern language a subjective participation in the divine consciousness, more feebly reflected, as would seem, in the memories, imaginations, and reasonings of our finite minds.
In pursuing these wonderful speculations Berkeley deviated widely from the direct line of English philosophy, and it is difficult not to believe that the deflection was determined by the influence of Malebranche, especially when we find that the writings of the Oratorian Father were included in his college studies. Moreover, a parallel line of idealistic development derived from the same source was evolving itself at the same time in English thought. John Norris (1657-1711), a correspondent of the Platonist Henry More, an opponent of Locke, and a disciple of Malebranche, had himself found an enthusiastic admirer in Arthur Collier (1680-1732), whose Clavis Universalis professed to be "a demonstration of the non-existence or impossibility of an external world" (1713). Both Norris and Collier, like Malebranche and Berkeley, were Churchmen; but so strong was the drift towards idealism that Leibniz, a layman and a man of science, contributed by his Monadology to the same current. Malebranche neither was nor could he be a complete idealist in the sense of denying the reality of matter; for the dogma of transubstantiation bound him, as a Catholic, to its acceptance, while Berkeley, Collier, and Leibniz, as Protestants, were under no such obligation. His idealism agreed more nearly with the Neo-Platonic doctrine of Archetypes in the divine Reason among which Matter was one. On the other hand, Berkeley probably borrowed from him the notion of a direct contact with God, the difference being that with the Cartesian it is conceived as an objective vision, with Locke's disciple as (if the expression may be permitted) a subjective con-consciousness. Leibniz, again, while abolishing Matter, retains an external world composed indeed of spirits and so far immaterial, but existing independently of God.
All these systems involve the negation of two fundamental scientific principles. The first is that every change must be explained by reference to an antecedent change to which it bears a strict quantitative relation. The second is that no particular change can be referred to another change as its necessary antecedent unless it can be shown by experience that a precisely similar couple of changes are, in fact, always so connected. Let me illustrate these principles by an example. I leave a kettle full of cold water on the fire, and on returning after a sufficient interval of time I find the water boiling. Had I stayed by the fire and watched the process, my kettle would—a popular proverb to the contrary notwithstanding—have certainly boiled as soon, but also no sooner for being helped by my consciousness. The essential thing is that energy of combustion in the fire should be turned into energy of boiling in the water. Now, what is Berkeley's interpretation of the facts? Fire, kettle, water, and ebullition are what in his writings are called "ideas"—i.e., phenomena occasionally in my mind, but always in God's mind. And according to this view the necessary antecedent to the boiling of the water is not the fire's burning, but God's consciousness of its burning, his perception being the essence of the operation. But it is proved by experience that neither my perception nor anyone else's ever made a single drop of water boil. In other words, perception is not in this instance a vera causa. Why, then, should the perception of any other mind, however exalted, have that effect?
Nor is this all. How does Berkeley know that God exists? Because, he says, to exist is to be perceived, and therefore for the universe to exist implies a universal Percipient. But he got the idea of God from other men, who certainly did not come by it as a generalisation from their perceptions; they got it by generalising from their voluntary actions, which do produce the changes that perception cannot produce. It will be said that volitions and the feelings that prompt them exist only in consciousness. In whose consciousness? In that of a spirit. And what is spirit apart from sensation, thought, feeling, and volition? Simply one of those abstract ideas whose existence Berkeley himself denied.