Julien Murzi (University of Salzburg)

Truth and paradox in context

The Liar Paradox is a seemingly valid proof of any sentence whatsoever that only resorts to logical rules and to seemingly platitudinous principles about ’true’. We argue that the key for solving the paradox is to accept that the Liar derivation is valid, up to its second last step, and that it doesn’t involve the proof of a contradiction. This requires assuming, apparently against all linguistic evidence, (i) that the truth predicate has an indexical element and (ii) that the Liar derivation involves a shift of context. We claim that (i) is actually uncontroversial and that a parallel with the notion of formal proof strongly suggests that (ii) should not be controversial either.