Reid, Thomas, 1710–96, Scottish philosopher. He taught at King's College, Aberdeen, and at the Univ. of Glasgow. He is known as the founder of the common-sense school of philosophy, also known as the Scottish school, a group that had considerable influence in Great Britain and the United States during the 19th cent. Common sense is regarded as self-evident knowledge, the means by which we know the objects of the external world. These objects are known by us in their true sense and not as copies or ideas. This is the theory of natural realism, and it is the point of difference with the theories of John Locke. Reid based morality on conscience or moral sense, the ethical position of intuitionism. He had considerable influence on Dugald Stewart and Sir William Hamilton. His writings include An Inquiry into the Human Mind on the Principles of Common Sense (1764), Essays on the Intellectual Powers of Man (1785), and Essays on the Active Powers of Man (1788).
See his Philosophical Works, ed. with notes and supplementary dissertations by Sir William Hamilton (2 vol, 8th ed. 1895, repr. 1967); A. J. Ayer and R. Winch, ed., British Empirical Philosophers (1968); N. Daniels, Thomas Reid's Inquiry (1989); K. Lehrer, Thomas Reid (1989).