Soundness Arguments for the consistency of a (mathematical) theory S aim to show that S is consistent by first showing or employing the fact that S is sound, i.e., that all theorems of S are true. Although soundness arguments are virtually unanimously accepted as valid and sound for most of our accepted theories, philosophers disagree about their epistemic value, i.e., about whether such arguments can be employed to improve our epistemic situation concerning questions of consistency. This article provides a (partial) (...) negative answer to this question and argues that soundness arguments cannot be employed to justify their conclusion. Additionally, soundness arguments are unconvincing; they cannot be employed to overcome reasonable open-mindedness about their conclusion. (shrink)

An old and well-known objection to non-classical logics is that they are too weak; in particular, they cannot prove a number of important mathematical results. A promising strategy to deal with this objection consists in proving so-called recapture results. Roughly, these results show that classical logic can be used in mathematics and other unproblematic contexts. However, the strategy faces some potential problems. First, typical recapture results are formulated in a purely logical language, and do not generalize nicely to languages containing (...) the kind of vocabulary that usually motivates non-classical theories—for example, a language containing a naïve truth predicate. Second, proofs of recapture results typically employ classical principles that are not valid in the targeted non-classical system; hence, non-classical theorists do not seem entitled to those results. In this paper, we analyze these problems and provide solutions on behalf of non-classical theorists. To address the first problem, we provide a novel kind of recapture result, which generalizes nicely to a truth-theoretic language. As for the second problem, we argue that it relies on an ambiguity and that, once the ambiguity is removed, there are no reasons to think that non-classical logicians are not entitled to their recapture results. (shrink)

When accepting an axiomatic theory S, we are implicitly committed to various statements that are independent of its axioms. Examples of such implicit commitments include consistency statements and reflection principles for S. While foundational acceptance has received considerable attention in this context, the study of implicit commitments triggered by weaker notions remains underdeveloped. This article extends the analysis investigating implicit commitments inherent in instrumental acceptance, comparing them with the implicit commitments involved in foundational acceptance. Concentrating on Reinhardt’s instrumentalism vis-à-vis Kripke–Feferman (...) theory of truth as a case study, we present a number of formal theories of acceptance motivated by Reinhardt’s program and we analyze their properties. We argue that, under reasonable assumptions, instrumental acceptance does entail non-trivial implicit commitments, yet weaker than those associated with foundational acceptance. (shrink)