Roy Wood Sellars, the American critical realist, taught philosophy at the University of Michigan. Although he was never as well known outside philosophical circles as some of his contemporaries, after the publication of his first book, Critical Realism, in 1916, Sellars maintained a substantial reputation among his fellow philosophers as a vigorously independent thinker. His thought was rigorous and critical; he never yielded to the fashionable movements of the day but steadfastly pursued his own original insights into basic philosophical problems.

The core of Sellars's philosophy is epistemological. He is concerned with showing that the critical realism of the philosopher is related to the "natural realism" of the "plain man." The philosopher reflects on the plain man's uncritical view of knowledge, which he clarifies and refines so that it is philosophically justifiable, but he does not vitiate its essential insistence upon the independence...