C. I. Lewis

Clarence Irving Lewis (b. 1883–d. 1964) is arguably the most important philosopher bridging the pragmatism of the golden age of William James and Charles Sanders Peirce and the analytic quasi-pragmatism of philosophers like W. V. Quine, Nelson Goodman, Wilfrid Sellars, and Hilary Putnam (the first three of whom were taught by him). Lewis’s philosophy as a whole reveals a unified systematic development from his dissertation in 1910, his early work in logic, the development of his epistemology in the 1920s and 1930s, his account of value theory in the 1940s and 1950s, culminating in his work in ethics, which occupied him until his death. Along the way he offered a devastating critique of American absolute idealism and offered a rich epistemology grounded in a Peircean kind of pragmatism. Early in his career Lewis wrote the first the history of logic in English, and, critical of the paradoxes of material implication, he developed an account of strict implication and a set of successively stronger modal logics, the S systems becoming the father of modern modal logic. Lewis was the most influential American philosopher from the mid-1930s until after his retirement in the 1950s. His work helped shape American philosophy as an academic endeavor and contributor to the growing acceptance of rigorous philosophical analysis and European logical empiricism. Lewis spent practically his entire career at Harvard University, bridging the Harvard of James and Royce and the modern department of Quine and Goodman. During his career he wrote six books and a hundred or so papers and reviews. A student of Josiah Royce, William James, and Ralph Barton Perry, a contemporary of Hans Reichenbach, Rudolf Carnap, and the logical empiricists of the 1930s and 1940s, and the teacher of Quine, William Frankena, Goodman, Roderick Chisholm, Roderick Firth, Sellars, and others, he played a pivotal role in shaping the marriage between pragmatism and empiricism that has come to dominate much of current analytic philosophy. Despite his significant contributions, his work soon became neglected and misinterpreted, lost in the influx of interest in Wittgenstein and the philosophy of language. Fortunately, this neglect has begun to wane.