Lewis, Clarence Irving
(1883-) Professor of Philosophy at Harvard. In Logic, Lewis has originated and defended strict implication (q.v.) in contrast to material implication, urging that formal inference should be based on a relation which can be known to hold without knowing what is true or false of this particular universe. See his Survey of Symbolic Logic, and his and C. H. Langford’s Symbolic Logic, esp. Ch. VIII. Lewis has argued also for “queer logics”, that is, abstract systems somewhat different from the abstract system usually interpreted as logic. Lewis raises the question how “queer” a system can be and still be interpretable properly as a system of logic.
In Epistemology (See his Mind and the World-Order) Lewis has presented a “conceptualistic pragmatism” based on these theses
“A priori truth is definitive in nature and rises exclusively from the analysis of concepts.”
“The choice of conceptual systems for . . . application [to particular given experiences] is . . . pragmatic.”
“That experience in general is such as to be capable of conceptual interpretation . . . could not conceivably be otherwise.” — C.A.B.