more from C.I. Lewis

Single Idea 9358

[catalogued under 5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic]

Full Idea

The fact is that there are several logics, markedly different, each self-consistent in its own terms and such that whoever, using it, avoids false premises, will never reach a false conclusion.

Gist of Idea

There are several logics, none of which will ever derive falsehoods from truth


C.I. Lewis (A Pragmatic Conception of the A Priori [1923], p.366)

Book Reference

Peirce,James,Dewey etc: 'Pragmatism - The Classic Writings', ed/tr. Thayer,H.S. [Hackett 1982], p.366

A Reaction

As the man who invented modal logic in five different versions, he speaks with some authority. Logicians now debate which version is the best, so how could that be decided? You could avoid false conclusions by never reasoning at all.