Stewart, Dugald (1753–1828)

Dugald Stewart was, after Thomas Reid, the most influential figure in the Common Sense School; he was a major influence on Victor Cousin and Théodore Jouffroy in France and on most academic philosophers in the United States. Along with Reid and Cousin, Stewart made the Scottish tradition the dominant philosophy in America for half a century. His Elements of the Philosophy of the Human Mind and Philosophy of the Active and Moral Powers of Man were his most important works and went through a number of printings. The abridged edition of his Active and Moral Powers was reprinted ten times from 1849 to 1868.

Stewart followed Reid in claiming that any philosophy which contravenes the principles of common sense must be false, and the problem is to discover and eliminate the premise which yields such results. He added the requirement that philosophical propositions must not change the meanings of concepts in ordinary life, and he also added a new dimension to Reid’s agency theory. More than any other writer he emphasized correctly the epistemic similarities between Reid and Immanuel Kant, but he followed Reid in avoiding Kant’s distinction between phenomena and noumena.

Stewart disagreed with Reid in avoiding the phrase ‘principles of common sense’ as misleading, rejected his mentor’s realistic interpretation of universals and provided his own nominalistic alternative. He also modified to some extent, though quite cautiously, Reid’s rigid inductivism and made some concessions to a realistic interpretation of scientific hypotheses. Stewart was equipped to discuss issues in the philosophy of science since he was well versed in mathematics and physics, having been professor of mathematics at Edinburgh for ten years before being named professor of moral philosophy. Stewart was arguably the first and finest philosopher of science in the Scottish tradition.