From the time of Locke down to the present day, there have been in Europe two main types of philosophy, and one of these owes both its doctrines and its method to Locke, while the other was derived first from Descartes and then from Kant. Kant himself thought that he had made a synthesis of the philosophy derived from Descartes and that derived from Locke; but this cannot be admitted, at least from a historical point of view, for the followers of Kant were in the Cartesian, not the Lockean, tradition. The heirs of Locke are, first, Berkeley and Hume; second, those of the French philosophes who did not belong to the school of Rousseau; third, Bentham and the philosophical Radicals; fourth, with important accretions from Continental philosophy, Marx and his disciples. But Marx's system is eclectic, and any simple statement about it is almost sure to be false; I will, therefore, leave him on one side until I come to consider him in detail.
In Locke's own day, his chief philosophical opponents were the Cartesians and Leibniz. Quite illogically, the victory of Locke's philosophy in England and France was largely due to the prestige of Newton. Descartes' authority as a philosopher was enhanced, in his own day, by his work in mathematics and natural philosophy. But his doctrine of vortices was definitely inferior to Newton's law of gravitation as an explanation of the solar system. The victory of the Newtonian cosmogony diminished men's respect for Descartes and increased their respect for England. Both these causes inclined men favourably towards Locke. In eighteenth-century France, where the intellectuals were in rebellion against an antiquated, corrupt, and effete despotism, they regarded England as the home of freedom, and were predisposed in favour of Locke's philosophy by his political doctrines. In the last times before the Revolution, Locke's influence in France was reinforced by that of Hume, who lived for a time in France and was personally acquainted with many of the leading savants.
The chief transmitter of English influence to France was Voltaire.
In England, the philosophical followers of Locke, until the French Revolution, took no interest in his political doctrines. Berkeley was a bishop not much interested in politics; Hume was a Tory who followed the lead of Bolingbroke. England was politically quiescent in their time, and a philosopher could be content to theorize without troubling himself about the state of the world. The French Revolution changed this, and forced the best minds into opposition to the status quo. Nevertheless, the tradition in pure philosophy remained unbroken. Shelley's Necessity of Atheism, for which he was expelled from Oxford, is full of Locke's influence.1
Until the publication of Kant's Critique of Pure Reason in 1781, it might have seemed as if the older philosophical tradition of Descartes, Spinoza and Leibniz were being definitely overcome by the newer empirical method. This newer method, however, had never prevailed in German universities, and after 1792 it was held responsible for the horrors of the Revolution. Recanting revolutionaries such as Coleridge found in Kant an intellectual support for their opposition to French atheism. The Germans, in their resistance to the French, were glad to have a German philosophy to uphold them. Even the French, after the fall of Napoleon, were glad of any weapon against Jacobinism. All these factors favoured Kant.
Kant, like Darwin, gave rise to a movement which he would have detested. Kant was a liberal, a democrat, a pacifist, but those who professed to develop his philosophy were none of these things. Or, if they still called themselves Liberals, they were Liberals of a new species. Since Rousseau and Kant, there have been two schools of Liberalism, which may be distinguished as the hard-headed and the soft-hearted. The hard-headed developed, through Bentham, Ricardo, and Marx, by logical stages into Stalin; the soft-hearted, by other logical stages, through Fichte, Byron, Carlyle, and Nietzsche, into Hitler. That statement, of course, is too schematic to be quite true, but it may serve as a map and a mnemonic. The stages in the evolution of ideas have had almost the quality of the Hegelian dialectic: doctrines have developed, by steps that each seem natural, into their opposites. But the developments have not been due solely to the inherent movement of ideas; they have been governed, throughout, by external circumstances and the reflection of these circumstances in human emotions. That this is the case may be made evident by one outstanding fact: that the ideas of liberalism have undergone no part of this development in America, where they remain to this day as in Locke.
Leaving politics on one side, let us examine the differences between the two schools of philosophy, which may be broadly distinguished as the Continental and the British respectively.
There is first of all a difference of method. British philosophy is more detailed and piecemeal than that of the Continent; when it allows itself some general principle, it sets to work to prove it inductively by examining its various applications. Thus Hume, after announcing that there is no idea without an antecedent impression, immediately proceeds to consider the following objection: suppose you are seeing two shades of colour which are similar but not identical, and suppose you have never seen a shade of colour intermediate between the two, can you, nevertheless, imagine such a shade? He does not decide the question, and considers that a decision adverse to his general principle would not be fatal to him, because his principle is not logical but empirical. When—to take a contrast—Leibniz wants to establish his monadology, he argues, roughly, as follows: Whatever is complex must be composed of simple parts; what is simple cannot be extended; therefore everything is composed of parts having no extension. But what is not extended is not matter. Therefore the ultimate constituents of things are not material, and, if not material, then mental. Consequently a table is really a colony of souls.
The difference of method, here, may be characterized as follows: In Locke or Hume, a comparatively modest conclusion is drawn from a broad survey of many facts, whereas in Leibniz a vast edifice of deduction is pyramided upon a pin-point of logical principle. In Leibniz, if the principle is completely true and the deductions are entirely valid, all is well; but the structure is unstable, and the slightest flaw anywhere brings it down in ruins. In Locke or Hume, on the contrary, the base of the pyramid is on the solid ground of observed fact, and the pyramid tapers upward, not downward; consequently the equilibrium is stable, and a flaw here or there can be rectified without total disaster. This difference of method survived Kant's attempt to incorporate something of the empirical philosophy: from Descartes to Hegel on the one side, and from Locke to John Stuart Mill on the other it remains unvarying.
The difference in method is connected with various other differences. Let us take first metaphysics.
Descartes offered metaphysical proofs of the existence of God, of which the most important had been invented in the eleventh century by St Anselm, Archbishop of Canterbury. Spinoza had a pantheistic God, who seemed to the orthodox to be no God at all; however that may be, Spinoza's arguments were essentially metaphysical, and are traceable (though he may not have realized this) to the doctrine that every proposition must have a subject and a predicate. Leibniz's metaphysics had the same source.
In Locke, the philosophical direction that he inaugurated is not yet fully developed; he accepts as valid Descartes' arguments as to the existence of God. Berkeley invented a wholly new argument; but Hume—in whom the new philosophy comes to completion—rejected metaphysics entirely, and held that nothing can be discovered by reasoning on the subjects with which metaphysics is concerned. This view persisted in the empirical school, while the opposite view, somewhat modified, persisted in Kant and his disciples.
In ethics, there is a similar division between the two schools.
Locke, as we saw, believed pleasure to be the good, and this was the prevalent view among empiricists throughout the eighteenth and nineteenth centuries. Their opponents, on the contrary, despised pleasure as ignoble, and had various systems of ethics which seemed more exalted. Hobbes valued power, and Spinoza, up to a point, agreed with Hobbes. There are in Spinoza two unreconciled views on ethics, one that of Hobbes, the other that the good consists in mystic union with God. Leibniz made no important contribution to ethics, but Kant made ethics supreme, and derived his metaphysics from ethical premisses. Kant's ethic is important, because it is anti-utilitarian, a priori, and what is called 'noble'.
Kant says that if you are kind to your brother because you are fond of him, you have no moral merit: an act only has moral merit when it is performed because the moral law enjoins it. Although pleasure is not the good, it is nevertheless unjust—so Kant maintains—that the virtuous should suffer. Since this often happens in this world, there must be another world where they are rewarded after death, and there must be a God to secure justice in the life hereafter. He rejects all the old metaphysical arguments for God and immortality, but considers his new ethical argument irrefutable.
Kant himself was a man whose outlook on practical affairs was kindly and humanitarian, but the same cannot be said of most of those who rejected happiness as the good. The sort of ethic that is called 'noble' is less associated with attempts to improve the world than is the more mundane view that we should seek to make men happier. This is not surprising. Contempt for happiness is easier when the happiness is other people's than when it is our own. Usually the substitute for happiness is some form of heroism. This affords unconscious outlets for the impulse to power, and abundant excuses for cruelty. Or, again, what is valued may be strong emotion; this was the case with the romantics. This led to a toleration of such passions as hatred and revenge; Byron's heroes are typical, and are never persons of exemplary behaviour. The men who did most to promote human happiness were—as might have been expected—those who thought happiness important, not those who despised it in comparison with something more 'sublime'. Moreover, a man's ethic usually reflects his character, and benevolence leads to a desire for the general happiness. Thus the men who thought happiness the end of life tended to be the more benevolent, while those who proposed other ends were often dominated, unconsciously, by cruelty or love of power.
These ethical differences are associated, usually though not invariably, with differences in politics. Locke, as we saw, is tentative in his beliefs, not at all authoritarian, and willing to leave every question to be decided by free discussion. The result, both in his case and in that of his followers, was a belief in reform, but of a gradual sort. Since their systems of thought were piecemeal, and the result of separate investigations of many different questions, their political views tended naturally to have the same character. They fought shy of large programmes all cut out of one block, and preferred to consider each question on its merits. In politics, as in philosophy, they were tentative and experimental. Their opponents, on the other hand, who thought they could 'grasp this sorry scheme of things entire', were much more willing to 'shatter it to bits and then remould it nearer to the heart's desire'. They might do this as revolutionaries, or as men who wished to increase the authority of the powers that be; in either case, they did not shrink from violence in pursuit of vast objectives, and they condemned love of peace as ignoble.
The great political defect of Locke and his disciples, from a modern point of view, was their worship of property. But those who criticized them on this account often did so in the interest of classes that were more harmful than the capitalists, such as monarchs, aristocrats, and militarists. The aristocratic landowner, whose income comes to him without effort and in accordance with immemorial custom, does not think of himself as a money grubber, and is not so thought of by men who do not look below the picturesque surface. The business man, on the contrary, is engaged in the conscious pursuit of wealth, and while his activities were more or less novel they roused a resentment not felt towards the gentlemanly exactions of the landowner. That is to say, this was the case with middle-class writers and those who read them; it was not the case with the peasants, as appeared in the French and Russian Revolutions. But peasants are inarticulate.
Most of the opponents of Locke's school had an admiration for war, as being heroic and involving a contempt for comfort and ease. Those who adopted a utilitarian ethic, on the contrary, tended to regard most wars as folly. This, again, at least in the nineteenth century, brought them into alliance with the capitalists, who disliked wars because they interfered with trade. The capitalists' motive was, of course, pure self-interest, but it led to views more consonant with the general interest than those of militarists and their literary supporters. The attitude of capitalists to war, it is true, has fluctuated. England's wars of the eighteenth century, except the American war, were on the whole profitable, and were supported by business men; but throughout the nineteenth century until its last years, they favoured peace. In modern times, big business, everywhere, has come into such intimate relations with the national State that the situation is greatly changed. But even now, both in England and in America, big business on the whole dislikes war.
Enlightened self-interest is, of course, not the loftiest of motives, but those who decry it often substitute, by accident or design, motives which are much worse, such as hatred, envy, and love of power. On the whole, the school which owed its origin to Locke, and which preached enlightened self-interest, did more to increase human happiness, and less to increase human misery, than was done by the schools which despised it in the name of heroism and self-sacrifice. I do not forget the horrors of early industrialism, but these, after all, were mitigated within the system. And I set against them Russian serfdom, the evils of war and its aftermath of fear and hatred, and the inevitable obscurantism of those who attempt to preserve ancient systems when they have lost their vitality.