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.
Chapter III.
THE THEORISTS OF KNOWLEDGE
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.