Clarence Irving Lewis (April 12, 1883 – February 3, 1964), usually cited as
C. I. Lewis, was an American academic
philosopher and the founder of
conceptual pragmatism. First a noted
logician, he later branched into
epistemology, and during the last 20 years of his life, he wrote much on
ethics. The
New York Times memorialized him as "a leading authority on symbolic logic and on the philosophic concepts of knowledge and value."