Today regarded as one of the most important figures of the later Scottish Enlightenment, he was renowned as a populariser of the work of Francis Hutcheson and of Adam Smith.

Trained in mathematics, medicine and philosophy,[1] his lectures at the University of Edinburgh were widely disseminated by his many influential students.

[2] He was the son of Matthew Stewart (1715–1785), professor of mathematics at the University of Edinburgh (1747–1772), and was born in his father's quarters at Old College.

[citation needed] He was educated at the High School and the University of Edinburgh, where he studied mathematics and moral philosophy under Adam Ferguson.

In 1771, in the hope of gaining a Snell Exhibition Scholarship and proceeding to Oxford to study for the English Church, he went to the University of Glasgow to attend the classes of Thomas Reid.

In Glasgow, Stewart boarded in the same house as Archibald Alison, author of the Essay on Taste, and a lasting friendship sprang up between them.

They drew extensively on his work in constructing educational programmes that rested on the assumption that women, and especially mothers, were intellectually capable of understanding the importance of the early association of ideas in the training of children's emotions and reasoning powers.

[6] Stewart spent the summers of 1788 and 1789 in France, where he met Suard, Degérando, and Raynal, and came to sympathise with the revolutionary movement.

[16] His friend and fellow Freemason, Robert Burns, made him an honorary member of Lodge St David, Tarbolton, No.

[18] His memory is also honoured by the "Dugald Stewart Building" (erected 2011) for the University of Edinburgh to house its Philosophy Department, on Charles Street, off George Square.

In 1793 he printed a textbook, Outlines of Moral Philosophy, which went through many editions; and in the same year he read before the Royal Society of Edinburgh his Account of the Life and Writings of Adam Smith.

Similar memoirs of William Robertson the historian and of Reid were afterwards read before the same body and appear in his published works.

[3] In 1805 Stewart published pamphlets defending John Leslie against the charges of unorthodoxy made by the presbytery of Edinburgh.

Part of his originality lay in his incorporation of elements of moderate empiricism and the French ideologists Laromiguière, Cabanis and Destutt de Tracy.