more from Alfred Tarski

Single Idea 19192

[catalogued under 5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle]

Full Idea

With our definition of truth we can prove the laws of contradiction and excluded middle. These semantic laws should not be identified with the related logical laws, which belong to the sentential calculus, and do not involve 'true' at all.

Gist of Idea

The truth definition proves semantic contradiction and excluded middle laws (not the logic laws)


Alfred Tarski (The Semantic Conception of Truth [1944], 12)

Book Reference

'Semantics and the Philosophy of Language', ed/tr. Linsky,Leonard [University of Illinois 1972], p.26

A Reaction

Very illuminating. I wish modern thinkers could be so clear about this matter. The logic contains 'P or not-P'. The semantics contains 'P is either true or false'. Critics say Tarski has presupposed 'classical' logic.