more from Alfred Tarski

Single Idea 8940

[catalogued under 5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox]

Full Idea

In Tarski's account of truth, self-reference (as found in the Liar Paradox) is prevented because the truth predicate for any given object language is never a part of that object language, and so a sentence can never predicate truth of itself.

Clarification

'This sentence is false' is a Liar sentence

Gist of Idea

Tarski avoids the Liar Paradox, because truth cannot be asserted within the object language

Source

report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Jennifer Fisher - On the Philosophy of Logic 03.I

Book Reference

Fisher,Jennifer: 'On the Philosophy of Logic' [Thomson Wadsworth 2008], p.38


A Reaction

Thus we solve the Liar Paradox by ruling that 'you are not allowed to say that'. Hm. The slightly odd result is that in any conversation about whether p is true, we end up using (logically speaking) two different languages simultaneously. Hm.