“In short, there are two principles which I cannot render consistent, nor is it in my power to renounce either of them; viz. that all our distinct perceptions are distinct existences, and that the mind never perceives any real connexion among distinct existences. Did our perceptions either inhere in something simple or individual, or did the mind perceive some real connexion among them, there would be no difficulty in the case” (ii. 551).
The closing sentences of this passage may be regarded as pointing to the very essence of the Kantian attempt at solution of the problem of knowledge. Hume sees distinctly that if conscious experience be taken as containing only isolated states, no progress in explanation of cognition is possible, and that the only hope of further development is to be looked for in a radical change in our mode of conceiving experience. The work of the critical philosophy is the introduction of this new mode of regarding experience, a mode which, in the technical language of philosophers, has received the title of transcendental as opposed to the psychological method followed by Locke and Hume. It is because Kant alone perceived the full significance of the change required in order to meet the difficulties of the empirical theory that we regard his system as the only sequel to that of Hume. The writers of the Scottish school, Reid in particular, did undoubtedly indicate some of the weaknesses in Hume’s fundamental conception, and their attempts to show that the isolated feeling cannot be taken as the ultimate and primary unit of cognitive experience are efforts in the right direction. But the question of knowledge was never generalized by them, and their reply to Hume, therefore, remains partial and inadequate, while its effect is weakened by the uncritical assumption of principles which is a characteristic feature of their writings.
The results of Hume’s theoretical analysis are applied by him to the problems of practical philosophy and religion. For the first of these the reader is referred to the article Ethics, where Hume’s views are placed in relation to those of his predecessors Theology and ethics. in the same field of inquiry. His position, as regards the second, is very noteworthy. As before said, his metaphysic contains in abstracto the principles which were at that time being employed, uncritically, alike by the deists and by their antagonists. There can be no doubt that Hume has continually in mind the theological questions then current, and that he was fully aware of the mode in which his analysis of knowledge might be applied to them. A few of the less important of his criticisms, such as the argument on miracles, became then and have since remained public property and matter of general discussion. But the full significance of his work on the theological side was not at the time perceived, and justice has barely been done to the admirable manner in which he reduced the theological disputes of the century to their ultimate elements. The importance of the Dialogues on Natural Religion, as a contribution to the criticism of theological ideas and methods, can hardly be over-estimated. A brief survey of its contents will be sufficient to show its general nature and its relations to such works as Clarke’s Demonstration and Butler’s Analogy. The Dialogues introduce three interlocutors, Demea, Cleanthes and Philo, who represent three distinct orders of theological opinion. The first is the type of a certain a priori view, then regarded as the safest bulwark against infidelity, of which the main tenets were that the being of God was capable of a priori proof, and that, owing to the finitude of our faculties, the attributes and modes of operation of deity were absolutely incomprehensible. The second is the typical deist of Locke’s school, improved as regards his philosophy, and holding that the only possible proof of God’s existence was a posteriori, from design, and that such proof was, on the whole, sufficient. The third is the type of completed empiricism or scepticism, holding that no argument, either from reason or experience, can transcend experience, and consequently that no proof of God’s existence is at all possible. The views of the first and second are played off against one another, and criticized by the third with great literary skill and effect. Cleanthes, who maintains that the doctrine of the incomprehensibility of God is hardly distinguishable from atheism, is compelled by the arguments of Philo to reduce to a minimum the conclusion capable of being inferred from experience as regards the existence of God. For Philo lays stress upon the weakness of the analogical argument, points out that the demand for an ultimate cause is no more satisfied by thought than by nature itself, shows that the argument from design cannot warrant the inference of a perfect or infinite or even of a single deity, and finally, carrying out his principles to the full extent, maintains that, as we have no experience of the origin of the world, no argument from experience can carry us to its origin, and that the apparent marks of design in the structure of animals are only results from the conditions of their actual existence. So far as argument from nature is concerned, a total suspension of judgment is our only reasonable resource. Nor does the a priori argument in any of its forms fare better, for reason can never demonstrate a matter of fact, and, unless we know that the world had a beginning in time, we cannot insist that it must have had a cause. Demea, who is willing to give up his abstract proof, brings forward the ordinary theological topic, man’s consciousness of his own imperfection, misery and dependent condition. Nature is throughout corrupt and polluted, but “the present evil phenomena are rectified in other regions and in some future period of existence.” Such a view satisfies neither of his interlocutors. Cleanthes, pointing out that from a nature thoroughly evil we can never prove the existence of an infinitely powerful and benevolent Creator, hazards the conjecture that the deity, though all-benevolent, is not all-powerful. Philo, however, pushing his principles to their full consequences, shows that unless we assumed (or knew) beforehand that the system of nature was the work of a benevolent but limited deity, we certainly could not, from the facts of nature, infer the benevolence of its creator. Cleanthes’s view is, therefore, an hypothesis, and in no sense an inference.
The Dialogues ought here to conclude. There is, however, appended one of those perplexing statements of personal opinion (for Hume declares Cleanthes to be his mouthpiece) not uncommon among writers of this period. Cleanthes and Philo come to an agreement, in admitting a certain illogical force in the a posteriori argument, or, at least, in expressing a conviction as to God’s existence, which may not perhaps be altogether devoid of foundation. The precise value of such a declaration must be matter of conjecture. Probably the true statement of Hume’s attitude regarding the problem is the somewhat melancholy utterance with which the Dialogues close.
It is apparent, even from the brief summary just given, that the importance of Hume in the history of philosophy consists in the vigour and logical exactness with which he develops a particular metaphysical view. Inconsistencies, no doubt, are to be detected in his system, but they arise from the limitations of the view itself, and not, as in the case of Locke and Berkeley, from imperfect grasp of the principle, and endeavour to unite with it others radically incompatible. In Hume’s theory of knowledge we have the final expression of what may be called psychological individualism or atomism, while his ethics and doctrine of religion are but the logical consequences of this theory. So far as metaphysic is concerned, Hume has given the final word of the empirical school, and all additions, whether from the specifically psychological side or from the general history of human culture, are subordinate in character, and affect in no way the nature of his results. It is no exaggeration to say that the later English school of philosophy represented by J. S. Mill made in theory no advance beyond Hume. In the logic of Mill, e.g., we find much of a special character that has no counterpart in Hume, much that is introduced ab extra, from general considerations of scientific procedure, but, so far as the groundwork is concerned, the System of Logic is a mere reproduction of Hume’s doctrine of knowledge. It is impossible for any reader of Mill’s remarkable posthumous essay on theism to avoid the reflection that in substance the treatment is identical with that of the Dialogues on Natural Religion, while on the whole the superiority in critical force must be assigned to the earlier work.
2. Hume’s eminence in the fields of philosophy and history must not be allowed to obscure his importance as a political economist. Berkeley had already, in the Querist, attacked the mercantile theory of the nature of national wealth and the Economics. functions of money, and Locke had, in a partial manner, shown that political economy could with advantage be viewed in relation to the modern system of critical philosophy. But Hume was the first to apply to economics the scientific methods of his philosophy. His services to economics may be summed up in two heads: (1) he established the relation between economic facts and the fundamental phenomena of social life, and (2) he introduced into the study of these facts the new historical method. Thus, though he gave no special name to it, he yet describes the subject-matter, and indicates the true method, of economic science. His economic essays were published in the volumes entitled Political Discourses (1752) and Essays and Treatises on Several Subjects (1753); the most important are those on Commerce, on Money, on Interest and on the Balance of Trade, but, notwithstanding the disconnected form of the essays in general, the other less important essays combine to make a complete economic system. We have said that Berkeley and Locke had already begun the general work for which Hume is most important; in details also Hume had been anticipated to some extent. Nicholas Barbon and Sir Dudley North had already attacked the mercantile theory as to the precious metals and the balance of trade; Joseph Massie and Barbon had anticipated his theory of interest. Yet when we compare Hume with Adam Smith, the advance which Hume had made on his predecessors in lucidity of exposition and subtlety of intellect becomes clear, and modern criticism is agreed that the main errors of Adam Smith are to be found in those deductions which deviate from the results of the Political Discourses. A very few examples must suffice to illustrate his services to economics.
In dealing with money, he refutes the Mercantile School, which had tended to confound it with wealth. “Money,” said Hume, “is none of the wheels of trade; it is the oil which renders the motion of the wheels more smooth and easy.” “Money Money. and commodities are the real strength of any community.” From the internal, as distinct from the international, aspect, the absolute quantity of money, supposed as of fixed amount, in a country, is of no consequence, while a quantity larger than is required for the interchange of commodities is injurious, as tending to raise prices and to drive foreigners from the home markets. It is only during the period of acquisition of money, and before the rise in prices, that the accumulation of precious metals is advantageous. This principle is perhaps Hume’s most important economic discovery (cf. F. A. Walker’s Money in its Relations to Trade and Industry, London, 1880, p. 84 sqq.). He goes on to show that the variations of prices are due solely to money and commodities in circulation. Further, it is a misconception to regard as injurious the passage of money into foreign countries. “A government,” he says, “has great reason to preserve with care its people and its manufactures; its money it may safely trust to the course of human affairs without fear or jealousy.” Interest. Dealing with the phenomena of interest, he exposes the old fallacy that the rate depends upon the amount of money in a country; low interest does not follow on abundance of money. The reduction in the rate of interest must, in general, result from “the increase of industry and frugality, of arts and commerce.” In connexion with this he emphasizes a too generally neglected factor in economic phenomena, “the constant and insatiable desire of the mind for exercise and employment.” “Interest,” he says in general, “is the barometer of the state, and its lowness an almost infallible sign of prosperity,” arising, as it does, from increased trade, frugality in the merchant class, and the consequent rise of new lenders: low interest and low profits mutually forward each other. In the matter Free trade. of free trade and protection he compromises. He says on the one hand, “not only as a man, but as a British subject I pray for the flourishing commerce of Germany, Spain, Italy and even France itself,” and condemns “the numerous bars, obstructions and imposts which all nations of Europe, and none more than England, have put upon trade.” On the other hand, he approves of a protective tax on German linen in favour of home manufactures, and of a tax on brandy as encouraging the sale of rum and so supporting our southern colonies. Indeed it has been fairly observed that Hume retains an attitude of refined mercantilism. With regard to taxation he takes very definite views. The best taxes, Taxation and national debt. he says, are those levied on consumption, especially on luxuries, for these are least heavily felt. He denies that all taxes fall finally on the land. Superior frugality and industry on the part of the artisan will enable him to pay taxes without mechanically raising the price of labour. Here, as in other points, he differs entirely from the physiocrats, and his criticism of contemporary French views are, as a whole, in accordance with received modern opinion. For the modern expedient of raising money for national emergencies by way of loan he has a profound distrust. He was convinced that what is bad for the individual credit must be bad for the state also. A national debt, he maintains, enriches the capital at the expense of the provinces; further, it creates a leisured class of stockholders, and possesses all the disadvantages of paper credit. “Either the nation must destroy public credit, or public credit will destroy the nation.” To sum up, it may be said that Hume enunciated the principle that “everything in the world is purchased by labour, and our passions are the only causes of labour”; and further, that, in analysing the complex phenomena of commerce, he is superior sometimes to Adam Smith in that he never forgets that the ultimate causes of economic change are the “customs and manners” of the people, and that the solution of problems is to be sought in the elementary factors of industry.
Bibliography.—1. Life.—J. H. Burton’s Life and Correspondence of David Hume (2 vols., 1846); Dr G. Birkbeck Hill, Letters of Hume to William Strahan; C. J. W. Francke, David Hume (Haarlem, 1907).
2. Works.—Until 1874 the standard edition was that of 1826 (reprinted 1854), in 4 vols. The best modern edition is that in 4 vols. by T. H. Green and T. H. Grose (containing a valuable introduction and excellent bibliographical matter); the Enquiry and the Treatise (1894 and 1896, Oxford), edited by L. A. Selby-Bigge.
3. Philosophic (the more important only can be quoted).—Huxley’s Hume (a popular reproduction of Hume’s views in “English Men of Letters” series); Sir L. Stephen’s English Thought in the XVIIIth Century (1876, especially ch. vi.); J. Orr, David Hume and his Influence on Philosophy and Theology (1903, especially ch. ix. on “Moral Theory of Hume”); H. Calderwood, David Hume (1898, especially ch. vii. on Hume’s attitude to religion); A. Seth, Scottish and German Answers to Hume; F. Jodl, Leben und Philosophie D. Humes (1872); E. Pfleiderer, Empirismus und Skepsis in D. Humes Philosophie (1874); G. Spicker, Kant, Hume und Berkeley (1875); G. Compayré, La Philosophie de D. Hume (1873); A. Meinong, Hume-Studien (1877, especially Hume’s nominalism); G. von Gižycki (a thorough exposition of Hume’s utilitarianism), Die Ethik D. Humes (1878); G. Lechartier, D. Hume, moraliste et sociologue (1900); M. Klemme, Die volkswirtschaftlichen Anchauungen D. Humes (1900); E. Marcus, Kants Revolutionsprinzip. Eine exakte Lösung des Kant-Hume’schen Erkenntnisproblems (1902); C. Hedvall, Humes Erkenntnistheorie (1906); R. Hönigswald, Über die Lehre Humes von der Realität der Aussendinge (1904); O. Quast, Der Begriff des Belief bei David Hume (1903). Hume’s relation to the society of his time is described in the Rev. H. G. Graham’s Social Life in Scotland and Scottish Men of Letters; “Jupiter” in Carlyle’s Autobiography. J. MacCosh published a short pamphlet (1884) containing interesting but perhaps not conclusive arguments on the Agnosticism of Hume and Huxley.