REID, THOMAS. - English philosopher, b. April 25, 1710 at Strachan, near Aberdeen, at whose university he was a professor from 1752 to 1764, the year in which he succeeded A. Smith in the chair of moral philosophy at the University of Glasgow, where he died on Oct. 7, 1796.
His first important work dates from 1763: An inquiry into the human mind on the principles of common sense (London), which was followed, among other secondary works, by the Essays on intellectual powers of man (Edinburgh 1785), and the Essays on the active powers of man (ibid. 1889). The philosophy of "common sense" (v.) or of the "Scottish School," of which R. is the founder, had a European influence, especially in France (Jouffroy, Cousin, Maine de Biran, etc.), in Italy (Galluppi, Rosmini, etc.), in Spain (Balmes), besides, of course, in England. For almost the whole of the first half of the 19th century the name of R. remained coupled with that of Kant in the critique of the empiricism (v.) of Hume and in the solution of the problems of cono-
knowledge and of the origin of ideas in relation to rationalism (v.) and to the empiricism of the 17th-18th centuries.
The method of observation and analysis, whose limit is experience, is typical of R. and of his school: to know the spirit, for him, is to observe and analyze the different faculties and the constitutive principles of man as an intelligent, active, social and moral being, respecting the insurmountable limits of phenomena and renouncing any explanation of their origin (metaphysical agnosticism). Sensation (v.) and perception (v.) are the primitive acts of human knowledge, by which we know the secondary and primary qualities (the one and the other objective) of things. The immediate object of our spirit is not "ideas," but things themselves. Sensation "testifies to the existence of the thing and of a quality inherent in it, a faculty of thinking and feeling and a permanent being or a spirit in which this faculty resides" (Inquiry, ch. 2, sec. 7). To admit among perceived objects and the perceiving subject the "intermediary" of "ideas" is to be unable to avoid the skeptical consequences of Berkeley's "idealism" (v.) and of Hume's phenomenism (v.), that is, it is to deny the reality of things, spiritual substance, the validity of the principle of causality, etc. Certainly we do not know what material and spiritual substance are, just as we cannot demonstrate the existence of things and of their qualities, but we know that they are not subjective ideas or impressions. In short, perception has an irresistible and immediate evidence (v.), which gives rise to the invincible belief (v.) that the perceiving subject exists and that the perceived things exist. On it every reasoning (v.) is founded, while it is independent of all reasonings. It is an innate suggestion which, if it explains nothing, makes one believe everything and gives man confidence. It is not common sense that must conform to philosophy, but philosophy to common sense. "The most immediate conclusions that reason draws from perception form common sense," or that body of data according to which men govern themselves in the ordinary affairs of life; the most remote form science. Science and common sense are so linked "that we cannot say precisely where the one begins and the other ends." Our knowledge of nature "may be compared to a tree that has its root, its trunk and its branches. Perception is the root, common sense the trunk, science the branches of it" (Inquiry, ch. 6, sec. 20). In short, for R., the reality of things and of spirits is the result of an instinct (v.) or of a primitive belief.
Thus the philosopher believed he had solved, against empiricism, the problem of the objectivity of knowledge and of the real. This problem, which is the same as Kant's in the face of Hume, has often brought the Scot close to the philosopher of Königsberg, especially in the 19th century. The distance, however, is enormous: R. remains within the sphere of empiricism without managing to overcome it, he ignores the Kantian concept of "critique," and his "belief" or "instinct" is something quite different from Kant's a priori. As Rosmini rightly observes (Nuovo saggio, II, Rome 1830, p. 245), the objectivity of knowledge cannot be founded on instinct: "common sense, authoritative in deposing such a fact (there exists an a priori cognition), is nevertheless unable to give any explanation of it."
To R. belongs the merit of having demonstrated that perception has not only a representative character and of having vindicated the principle of the activity of consciousness against that of passivity, proper to the empiricist psychology of his time and of Condillac.
Bibliography5 works
M. Federico Sciacca