Hume's philosophical fame rests primarily on the fearless and unrelenting way in which he carried to their logical conclusion the. implicit assumptions of the Empiricist school of. Great Britain and, for the matter of that, of ,the entire philosophy of the Enlightenment. Among the most important heirlooms handed down to the Enlightenment from the Schoolmen was the notion of substance.
The Aristotelian logic made every proposi tion essentially the attribution or denial of some predicate to some subject. As a natural and even necessary consequent of this, the Middle Ages and the Enlightenment viewed every rela tion under the aspect of a subject-predicate relation. The tendency, moreover, was to re gard certain entities, not merely as in the sit uation of subjects, but as subjects in their very essence, and others as essentially predicates. Locke already saw that if every fact is a pred ication of an attribute to a subject, and if such a predication, as he thought, consists in the modification of the subject• by the predicate, the unmodified subject or substance is not sus ceptible to any cognition in the least analogous 0 that which we have of the modified subject. Berkeley took the next step, saw that an un knowable substratum} is useless for explanatory purposes and ousted substance from the ma terial world. However, he retained the old stantial notion of unity essentially unmodified in his explanation of the unity of conscious ness the soul, /t was left to Hume to expel substance from its last hiding-place, and to view mind and matter alike as mere aggre gates of impressions and ideas in essence no more mental than materiaL It is important to note that Hume, no less than his predecessors, retained the opinion that unity is essentially of a substantial character. For this reason he interpreted hi reputation of the substantial character of consciousness as a refutation of all intrinsic unity whatever which consciousness might possess. This led to his associationism: he believed that ideas group themselves together according to the principles of resemblance• contiguity in time or place, and cause and effect." Owing to his inability to un
derstand relations as apart from substance, and owing, moreover, to the imperfect development of the notions of infinite and infinitesimal which characterized all his predecessors and contem poraries, he was forced to View time and space as mere aggregates formed by the ,nixtaposition of a finite number of minima,diVislbilia, Cause comes to be merely an idea produced in the mind by the constant concomitance of two states and their resulting association.
Hume left the universe of his philosophy in danger of falling to pieces from -,laeer lack of any principle of cohesion — indeed, of any prin ciple at all. It is space and time are aggrega tions without arrangement ; his cause in coex istence without connection. It is this destruc tion of the unity of the uitlet bystems which has given Hume a reputation for scepticism. Hume's chief . work is destructive,yet . by this very destruction he showed netessity and prepared the way for a theory of the universe which should not found its unity on the in secure -basis of substance. The first definite step toward this theory was taken by Kant, whom Hume "wakened from his slumber, In ethics Hume is 'a utilitarian. He believes that pleasure and pain are the only springs of action, and that utility to the race is the end of all good action. Whitt hp mnphpsixes the share played by intuition in all ethical matters, he does not deny all efficacy to reason. He is a rigid determinist. Consult Burton, J. H., 'Life and Correspondence of David Hume' (Edin burgh 18440 Georg von, (Die Ethic David Humes'. (1i eslau 1878) , Hume, D., Own Life' (London 1777); Huxley, T. H., 'David Hume' (London 1879); Hyslop, J. H, 'The Ethics of Hume' (Boston 1893); Jodi, 'David. Humes, Lehre von .der Erkennttuss' (Halle 1871)•, Knight, W., burgh 1886); Orr, J. 'David Hume and his In fluence on Philosophy and Theology' (New York 1903) ; Seth, A., (English Philosophers and Schools of Philosophy> (London 1912).