The Scottish philosopher, clergyman, and teacher Thomas Reid (1710-1796) originated the school of thought known as the philosophy of common sense.

Thomas Reid was the son of Lewis and Margaret Reid. He was born on April 26, 1710, at Strachan, Kincardineshire. Until he was 12 years old, he was educated at home and in the local parish school; he then entered Marischal College, from which he graduated in 1726. During the next decade he studied theology and read widely, and in 1737 he became a Presbyterian minister of the Church of Scotland. In 1740 Reid married his cousin Elizabeth Reid, and during their long life together they raised nine children. In 1752 he gave up his ministry at New Machar to become a professor of philosophy at King's College, Aberdeen. His best-known work, An Inquiry into the Human Mind on the Principles of Common Sense (1764), was derived essentially from material he had presented to the local philosophical society, which he had established.

Although David Hume claimed that his own major work, A Treatise on Human Nature (1739), "fell stillborn from the press," Reid seems to have been one of its few original readers. The two Scots, who were contemporaries, conducted an infrequent but complimentary correspondence, and Reid wrote, "I shall always avow myself as your disciple in metaphysics." In 1753 Reid succeeded Adam Smith, the famous economist, as professor of moral philosophy at Glasgow. He continued teaching until he retired at the age of 71. For the remaining 15 years of his life Reid published extensively. The two most important works of this period were Essays on the Intellectual Powers of Man (1785) and Essays on the Active Powers of Man (1788). Reid died on Oct. 7, 1796.

The philosophy of common sense took its point of departure from Hume's skepticism toward impressions and ideas. One of the chief tenets of modern classical philosophy is the representative theory of perception, which assumes that the immediate object of sensation is, in fact, a mental image that presents man with a world of material objects. Likewise, the relations between conceptual ideas are brought about by associations from past experience that are imaginatively projected into the future. Hume's skepticism led him to conclude that inferences on the basis of impressions and ideas are a matter of custom and belief rather than logical inference or demonstration. Reid's purpose was to reject such analysis as "shocking to common sense" and to rely on a description of the way in which perception, conception, and belief work together to produce an instinctive conviction of the validity of man's sensations of the external world and of other selves.

Further Reading

• Renewed interest in Reid's work is evident in Timothy Duggon's edition of Reid's An Inquiry into the Human Mind (1970). It partially supplements The Works of Thomas Reid, edited by Sir William Hamilton (2 vols., 1846-1863). This collection also contains Dugald Stewart's Account of the Life and Writings of Thomas Reid (1903). Studies of Reid include A. Campbell Fraser, Thomas Reid (1898), and Olin McKendree Jones, Empiricism and Intuitionism in Reid's Common Sense Philosophy (1927).
• Lehrer, Keith, Thomas Reid, London; New York: Routledge, 1991.