Thomas ReidThomas Reid (1710-1796), Scottish philosopher, and a contemporary of David Hume, was the founder of the Scottish School of Common Sense, and played an integral role in the Scottish Enlightenment. For the first part of his life, he lived in Aberdeen, where he created the "Wise Club" (a literal-philosophical association) and conceived the most part of his first work. In 1764 he was called to substitute Adam Smith at the University of Glasgow and published his "Inquiry".
Reid believed that common sense -- a term he used in a special philosophical sense -- is or at least should be at the foundation of all philosophical inquiry.
In his day and for some years into the 19th century, he was regarded as more important than David Hume. He advocated direct realism, or common sense realism, and argued strongly against the Theory of Ideas advocated by John Locke, Rene Descartes, and (in varying forms) nearly all Early Modern philosophers who came after them. He had a great admiration, by the way, for Hume, and also asked him to correct the first manuscript of his (Reid's) "Inquiry"
His theory of knowledge had a strong influence on his theory of morals. He himself thought all the epistemology was an introductory part to practical ethics: when we are confirmed in our common believes by philosophy, all we have to do is to act accordingly to them, because we know what is right. His moral philosophy reminds also the latin stoicism (he often quotes Cicero, from whom he takes the term "sensus communis", mediated by the Scolastica and St. Thomas Aquinas) and the christian way of life.
His reputation waned after attacks on the Scottish School of Common Sense by Immanuel Kant and John Stuart Mill, but his was anyway the philosophy taught in the colleges of North America, during all the XIX century. His reputation has arisen again in the wake of the advocacy of common sense as a philosophical method or criterion by G. E. Moore early in the century, and more recently due to attention given Reid by contemporary philosophers such as William Alston and Alvin Plantinga.
He wrote a number of important philosophical works, including Inquiry into the Human Mind on the Principles of Common Sense (1764, Glasgow & London), the Essays on the Intellectual Powers of Man (1785) and the Essays on the Active Powers of Man (1788).