all men is soon destroyed by the slightest philosophy. And no man who reflects ever doubted that the existences which we consider, when we say, this house and that tree, are nothing but perceptions in the mind, and fleeting copies or representations of other existences which remain uniform and independent. Even the primary qualities of extension and solidity are perceptions of the mind. (Berkeley.)

Are these perceptions produced by external objects resembling them? Here experience, which alone can answer this question of fact, is and must be entirely silent. Do external objects at least exist? Experience is equally silent on this point. However, to doubt the existence of bodies is an excessive scepticism, which action and employment, and the common occupations of life, subvert. This excessive scepticism, or Pyrrhonism, true scepticism rejects as barren. Every time it attempts to reappear, nature puts it to flight. Nevertheless, the existence of bodies, being a matter of fact, is incapable of demonstration. The only objects of real knowledge and demonstration are quantity and number. Experience decides concerning all matters of fact and existence, and experience never goes beyond probability.2— (Carneades.)

Hume's teachings were violently opposed, in the name of common-sense and morality, by THOMAS REID, the founder of the so-called Scottish school, and by his disciples,

1 Essay concerning Human Understanding, p. 130.

2 In excluding physics from the sphere of pure knowledge, the idealist Plato advances the same opinion.

1710-1796. Professor at Glasgow. Inquiry into the Human Mind on the Principles of Common-sense, London, 1764 ff. [Selections from the Inquiry by E. Sneath in Series of Modern Philosophers, New York, 1892. Essays on the Intellectual Powers of Man, 1785; Essays on the Active Powers of Man, 1788. Complete works, ed. by W., Hamilton, Edinburgh, 1827 ff. On the Scotch School see James McCosh, The Scottish Philosophy, London, 1875; New York, 1890.TR.].

OSWALD, BEATTIE,2 and DUGALD STEWART.3 All of these men were psychologists of merit, but, with the exception of Reid, mediocre metaphysicians. In order to refute Hume it was necessary to put oneself in his position, the critical

position, to use his own weapons, to renew the inquiry into the human understanding, and, if possible, to make it more thorough and complete. Kant, the most illustrious continuer and the most acute critic of the Scotch philosopher, saw that very clearly. "Common-sense," he says, "is a precious gift of God. But we must prove it by its acts, by deliberate and rational thought and speech, and not appeal to it as to an oracle, whenever reasons fail us. It is one of the subtle devices of our times to appeal to common-sense when our knowledge gives out, and the shallowest fool confidently measures his strength with the profoundest thinker's. . . . And what is this appeal to common-sense but a bid for the applause of the rabble, which cannot but bring the blush to the cheek of the philosopher? I cannot help

1 Appeal to Common Sense in Behalf of Religion, Edinburgh, 1766. 21735-1803. Professor at Edinburgh. Essay on the Nature and Immutability of Truth in Opposition to Sophistry and Scepticism, Edinburgh, 1770; Theory of Language, London, 1778; Elements of the Science of Morals, 1790-1793.

1753-1828. Elements of the Philosophy of the Human Mind, 3 vols., London, 1792-1827; Outlines of Moral Philosophy, 1793 [ed. with critical notes by J. McCosh, London, 1863. Collected works, ed. by W. Hamilton, 10 vols., Edinburgh, 1854-1858. Thomas Brown (1778-1820), a pupil of Stewart, approximates Hume (Inquiry into the Relation of Cause and Effect, Edinb., 1803 ff.) — TR.].

• In the philosophy of William Hamilton (1788-1856), the Scottish school, following the example of the Academy, culminates in scepticism, which it had undertaken to combat in David Hume. Sir W. Hamilton was noted for his Discussions on Philosophy and Literature, London and Edinburgh, 1852; 3d ed., 1866; Lectures on Metaphysics, 2d ed., 1860, and on Logic, 2d ed., 1866. See J. Stuart Mill, Examination of Sir William Hamilton's Philosophy, London, 1865; 5th ed., 1878: [Veitch, Hamilton (Philosophical Classics)].

thinking that Hume had as much good sense as Beattie." Reason can be corrected by reason alone.1

It is true, Hume's philosophy was not unassailable. There were breaks in his criticism; difficulties were eluded rather than solved. If experience is the sole source of knowledge, whence arises the exceptional character of absolute certainty which Hume himself concedes to mathematics? If there is nothing in the intellect which was not previously in the senses, how shall we explain the ideas of cause, necessary connection, and necessity? As was seen, the Scotch criticist explains the idea of necessary connection by the principle of habit. After the constant conjunction of two objects, we are determined by custom alone to expect the one from the appearance of the other. But this explanation does not suffice. The idea of necessity cannot come from experience alone, for the widest experience supplies us only with a limited number of cases; it never tells us what happens in all cases, and consequently does not yield necessary truth. Besides, it is not true that the notion of causality is that of necessary contiguity in time.2 Causality signifies connection, and therefore contains an element not

1 Prolegomena zu einer jeden künftigen Metaphysik, Preface, vol. III. (Rosenkranz), p. 8.

• What succession, as Thomas Reid aptly remarks, is older and more regularly observed than that of day and night? Now, it never occurs to any one to consider night as an effect of day, and day as the cause of night. Moreover, there is this peculiarity about the truths of experience that the certainty we get from them is susceptible of increase and diminution. After a second successful test, the physician is more convinced of the virtue of his medicine than after the first, and so on, until a long line of authentic cases changes into certainty what was at first a mere presumption and surmise. The case is quite different with a truth like the following: Nothing happens without a cause. The child, whose experience has just begun, believes in it with the same instinctive force as the adult and the old man, and experi ences multiplied by the myriads can neither increase nor diminish its certainty.

included in the notion of contiguity. Now, Hɩ ne expressly states that one event follows another, but that we can never observe any tie between them. They seem conjoined, but never connected. Hence, if experience never shows us a cause, but only a succession of events (for that is what Hume means by the ill-chosen term conjunction, which is synonymous with connection), must we not either negate the idea of causation, or infer a different origin for it?

At this point Hume's criticism is corrected and completed by that of Kant.2

1 An Enquiry concerning Human Understanding, sec. VII., p. 62. 2 [Before the advent of Kant's criticism, German philosophy was dominated by the Leibnizo-Wolffian school (see pp. 368 f.), which culminated in a form of eclecticism similar to the English common-sense philosophy. J. H. Lambert (1728-1777), one of Kant's correspondents, attempts to reconcile Wolff and Locke, German metaphysics and English empiricism (Kosmologische Briefe, Augsburg, 1761); N. Tetens (1736-1805), who influenced Kant, aims to reconcile the rationalistic and sensationalistic psychology (Versuch über die menschliche Natur, 1776); M. Knutzen (died 1751), Kant's teacher, endeavors to reconcile Wolffian metaphysics, Newton's natural philosophy, and orthodox theology. Other representatives of this eclectic movement are the socalled popular philosophers, whose chief aim is to popularize philosophy: Moses Mendelssohn (1729-1786; complete works, 7 vols., Leipsic, 1843-44); C. Garve (1742-1798), the translator of Ferguson's and A. Smith's writings; J. J. Engel (1741-1802; Der Philosoph für die Well, 1775-77); T. Abbt (1738-1766; Vom Tode fürs Vaterland, Berlin, 1761); Ernst Platner (1744-1818; Philosophische Aphorismen, 1776); F. Nicolai (1733-1811). To the Aufklärung also belong the deist H. S. Reimarus (1694-1765; Abhandlungen von den vornehmsten Wahr heiten der natürlichen Religion, Hamburg, 1754, 6th ed., 1794; and the poet G. E. Lessing (1729-1781). - TR.]

§ 62. Kant1

IMMANUEL KANT, born in Königsberg, Prussia, 1724, was the son of plain people. His paternal grandparents emigrated to Germany from the fatherland of Hume. After pursuing his studies at the University of his native

1 [For the period beginning with Kant see, besides the general and modern histories of philosophy, the works of Chalybæus, Biedermann, Michelet, Willm, Fortlage, Harms, Zeller, Seth, Royce, etc., mentioned on pp. 12-15; also O. Liebmann, Kant und die Epigonen, Stuttgart, 1865.-TR.]

2 Kant's complete works, published by: G. Hartenstein, 10 vols., Leipsic, 1838-39; new edition, 8 vols., Leipsic, 1867-69; Rosenkranz and Schubert, 12 vols., Leipsic, 1838-42; [with notes in Kirchmann's Philosophische Bibliothek, Heidelberg, 1880 ff. The three Critiques and several other works, ed. by K. Kehrbach, in Reclam's Universal-Bibliothek, Leipsic. A new edition is being prepared by the Berlin Academy of Sciences. B. Erdmann has published Reflexionen Kant's zur kritischen Philosophie in 2 vols., Leipsic, 1882-84; R. Reicke, Lose Blätter aus Kant's Nachlass, Königsberg, 1889, 1895]. Charles Villers, Philosophie de Kant, Metz, 1801; Amant Saintes, Histoire de la vie et de la philosophie de Kant, Paris, 1844; V. Cousin, Leçons sur Kant, Paris, 1842, 4th ed., 1864 [Engl. tr. by A. Henderson, London, 1870]; Émile Saisset, Le scepticisme, Enesideme, Pascal, Kant, Paris, 1865; D. Nolen, La critique de Kant et la métaphysique de Leibniz, Paris, 1875; M. Desdouits, La philosophie de Kant d'après les trois critiques, Paris, 1876; [F. Paulsen, Versuch einer Entwickelungsgeschichte der kantischen Erkenntnisstheorie, Leipsic, 1875; A. Riehl, Der philosophische Kriticismus, etc., vol. I., Leipsic, 1876; E. Caird, The Philosophy of Kant, London, 1876; same author, The Critical Philosophy of Kant, 2 vols., London and New York, 1889; C. Cantoni, E. Kant, 3 vols., Milan, 1879-1883; Adamson, The Philosophy of Kant, Edinburgh, 1879; W. Wallace, Kant (Philosophical Classics), London, 1882; K. Fischer's Kant in his History of Philosophy (see p. 12); F. Paulsen, Was Kent uns sein kann (V. f. w. Ph., pp. 1-96, 1881); Journal of Speculative Philosophy, ed. by W. T. Harris, July and October numbers, 1881; J. G. Schurman, Kant's Critical Problem (Phil. Rev., II., 2, 1893); E. Adickes, Kant-Studien, Kiel and Leipsic, 1895; same author, Bibliography of Writings by Kant and on Kant, in the Philosophical Review, beginning with vol. II., 3 ff. See also Schopenhauer's Kritik det Kantischen Philosophie, and T. H. Green's Lectures on the Philosophy of Kant. -TR.]