Pragmatism, sometimes called the characteristically American philosophy, is usually considered to have been best exemplified in the writings of William James, Charles S. Peirce, and John Dewey. The position is sometimes called “humanism” (for example, the point of view developed by the English philosopher F. C. S. Schiller) and sometimes called “instrumentalism.” Although there were many variations in the specific philosophies of these individuals, they shared a belief in the relativity of truth to the concrete verification processes and to the practical role that humanity plays in the world. In general they also were in agreement in being more or less hostile toward metaphysics, at least of an absolutistic sort, and feeling that a view of the universe that “made no difference” to the common person, either in the sense that it could not be confirmed or disproved by observable phenomena or in the sense that it did not help one to live a better life, was really meaningless, and that indulgence in speculation of this kind was a waste of time.
C. I. Lewis had many of the same interests that Peirce did, and like Peirce he made important contributions to the fields of the philosophy of science and symbolic logic. Lewis’s A Survey of Symbolic Logic (1918) is one of the standard works in this area. In Mind and the World-Order, this broad knowledge of the nature of deductive systems and of the difference between a priori and a posteriori cognition is used to develop a position that Lewis called “conceptualistic pragmatism.” It has much in common with the views of the earlier pragmatists, and Lewis frankly acknowledges his indebtedness to these philosophers, but it also has certain distinctive aspects. For this reason it deserves careful consideration as an important philosophical position. Lewis modified pragmatism to make it more compatible with the methodologies of the mathematical and natural sciences.