REID, THOMAS the founder of the "Scottish School" of philosophy, was born on April 26, 1710, at Strachan in Kincardineshire, where his father was minister. He graduated at Aberdeen in 1726, remained there as librarian for ten years, and was presented to the living of Newmachar near Aberdeen in 1737. His first philosophical work, Essay on Quantity, occasioned by reading a Treatise in which Simple and Compound Ratios are applied to Virtue and Merit, denying the possibility of mathe matical treatment of moral subjects, appeared in the Transactions of the Royal Society (1748). In 174o Reid married a cousin, the daughter of a London physician. In 1752 he became professor of philosophy at King's college, Aberdeen. The Aberdeen Philo sophical Society (the "Wise Club"), which numbered among its members Campbell, Beattie, Gerard and Dr. John Gregory, was mainly founded by Reid, who was secretary for the first year (1758). Reid propounded his point of view in the Enquiry into the Human Mind on the Principles of Common Sense In this year, Reid succeeded Adam Smith professor of moral philosophy at Glasgow.
After 17 years he retired to complete his philosophical system. The Essays on the Intellectual Powers of Man appeared in 1785, and their ethical complement, the Essays on the Active Powers of the Human Mind, in 1788. These, with an account of Aristotle's Logic appended to Lord Kames's Sketches of the History of Man (1774), conclude the list of works published in Reid's lifetime. He died of paralysis on Oct. 7, 1796.
The key to Reid's philosophy is to be found in his revulsiOn from the sceptical conclusions of Hume. In several passages of his writings he expressly dates his philosophical awakening from the appearance of the Treatise of Human Nature. In the dedica tion of the Enquiry, he says : "The ingenious author of that treatise upon the principles of Locke—who was no sceptic—hath built a system of scepticism which leaves no ground to believe any one thing rather than its contrary. His reasoning appeared to me to be just ; there was, therefore, a necessity to call in question the principles upon which it was founded, or to admit the conclusion." Having decided that the rationalist philosophy was subversive of religion and morals he examined the doctrine, which he de clared to be contrary to experience. He appealed not to eternal truths, but to the testimony of experience. He maintained that
we do not start with "ideas," and afterwards refer them to ob jects ; we are never restricted to our own minds, but are from the first immediately related to a permanent world. There are certain presuppositions unassailable by doubt which are older and more authoritative than any philosophy. Among these he places the belief in a material external world and in the existence of the soul. Reid has a variety of names for the principles which, by their presence, lift us out of subjectivity into perception. One of these, "principles of common sense," which became the current one, conveyed a false impression of Scottish philosophy. Reid did not merely appeal from the reasoned conclusions of philosophers to the unreasoned beliefs of common life. His real mode of pro cedure is to redargue Hume's conclusions by a refutation of the premises inherited by him from his predecessors. Reid every where unites common sense and reason, making the former "only another name for one branch or degree of reason." Reason, as judging of things self-evident, is called common sense to distin guish it from ratiocination or reasoning. And in regard to Reid's favourite proof of the principles in question by reference to "the consent of ages and nations, of the learned and unlearned," it is only fair to observe that this argument assumes a much more scientific form in the Essays, where it is almost identified with an appeal to "the structure and grammar of all languages." "The structure of all languages," he says, "is grounded upon common sense." To take but one example, "the distinction between sen sible qualities and the substance to which they belong, and between thought and the mind that thinks, is not the invention of philoso phers; it is found in the structure of all languages, and therefore must be common to all men who speak with understanding" (Hamilton's Reid, pp. 229 and 454).
BIBLIOGRAPHY.—The best edition of Reid's Works is that by Sir William Hamilton (2 vols.). See also "Reid and the Philosophy of Common Sense" in J. F. Ferrier's Lectures, ed. Grant and Lushington (1866) ; A. C. Fraser, Thomas Reid ("Famous Scots Series," 1898) ; K. Peters, Thomas Reid als Kritiker von David Hume (Leipzig, 1909) ; 0. M. Jones, Empiricism and Intuitionism in Reid's Common Sense Philosophy (192 7) .