A note on Etchemendy's and Prawitz's reduction principles for the Tarskian and model‐theoretic concept of consequence

One of Etchemendy's arguments against the Tarskian and model-theoretic notion of logical truth is based on a reduction principle according to which a universally quantified sentence is true if, and only if, all of its instances are logically true. The reduction of logical truth to mere truth reveals that the concept of validity at play in Tarski and in model-theory relies upon extra-logical assumptions. A similar reduction had already been put forward by Prawitz, although not with focus on extra-logical assumptions. Prawitz's reduction concerns rather the possibility of understanding the Tarskian and model-theoretic approach as implying any epistemic modality. We take into account a possible strategy that an advocate of Tarski and model-theory may use against Etchemendy's objection, and argue that this strategy fails with respect to Prawitz's criticism. This permits us to shed light upon a difference between Prawitz's and Etchemendy's standpoints: while Etchemendy's reduction shows that the Tarskian and model-theoretic notion of logical truth cannot be understood as an adequate formal counterpart of truth-preservation solely by virtue of logical form, Prawitz's reduction insists on the fact that truth-preservation solely by virtue of logical form is insufficient for epistemic modality to obtain.