Stewart, a brilliant teacher, was an influential member of Scottish Enlightenment circles. He was taught by Ferguson, who recommended he go to Glasgow to attend the common-sense philosopher Reid’s lectures. Reid became his mentor, and Stewart took over Ferguson’s position when his former teacher was sent to America. Among Stewart’s own students were Scott, Mill and Sydney Smith. He was influenced by Monboddo, friendly with Burns, Edgeworth and Playfair, and observed the beginning of the French Revolution with Jefferson. A member of Adam Smith’s Oyster Club, he wrote biographies of Smith and Reid.