5-6; Gomez-Torrente, M., "

Logical Truth", en: The Stanford Encyclopedia of Philosophy, verano de 2006 (http://plato.stanford.edu/entries/logical-truth/), editada por E.N.

Finally, the definitions of validity (

logical truth), consistency, and logical consequence are the familiar ones of standard model-theoretic semantics.

Afortiori, if [Phi] is a

logical truth, then there should be a proof of [Phi] (with no undischarged premises) in which every line is a sub-formula of [Phi].

Hintikka [1955] contains a theorem that for any nth-order sentence S, there is a second-order sentence S+ such that if S is satisfiable then so is S+, and S is a

logical truth if and only if S+ is a

logical truth.

77-106 and "Carnap and

Logical Truth," in The Ways of Paradox, pp.

Problem-solving at the Intrasystemic level is based on the more or less absolute certainty of

logical truth, with the implication that there is only one truth to be constructed during problem solving.

The connection between the translation argument and Quine's criticism of Carnap's conception of

logical truth is investigated, and an apparent tension is identified between two strands of the argument: one according to which the idea of logical aliens are empty, the other according to which such aliens are just very unlikely.

Hence, any specific instance of [&E] counts as a safely known

logical truth. Some of the perennial questions within the epistemology of logic are due to the sense that such knowledge exhibits a remarkable immunity to counterexample: i.e., it is not just that I have yet to encounter a situation in which a conjunction failed to entail one of its conjuncts (which would be remarkable enough, to be sure), but, further, there is the atavistic intuition that such a scenario would be both epistemically inconceivable and metaphysically impossible.

Thus Frege could neither have our concept of

logical truth in contrast to contingent truth, nor a corresponding formal semantic concept of consequence.

Logical truth and validity are based on how our language is defined, independently of what extralinguistic reality might look like.

My second problem is about Sainsbury's criticism of the usual justification for the positive free logic take on the unhedged (12), based on the

logical truth that everything is self-identical.

(21) Richard Heck (forthcoming) holds that Frege was in doubt only about the status of Axiom V as a

logical truth, not about its truth.