Logic, logical form and the disunity of truth

Abstract

Atomic sentences or the propositions they express can be true, as can logically complex sentences composed out of atomic sentences. 1 A comprehensive metaphysics of truth aims to tell us, in an informative way, what the truth of any sentence whatsoever consists in, be it atomic or complex. Monists about truth are committed to truth always consisting in the same thing, no matter which sentence you consider. Pluralists about truth think that the nature of truth is different for different sets of sentences. The received view seems to be that logically complex sentences and indeed logic itself somehow impose a monistic constraint on any comprehensive metaphysics of truth. In what follows, I argue that the received view is mistaken.

Alethic Pluralism, Logical Validity, and Natural Truth

“…7 Lewis (1983). 8 Recently, some authors, such as Gamester (2018) and Lynch and Pedersen (2018) have argued that mixed inferences pose no serious problem to strong truth pluralism. Basically, the reason is that the idea of truth preservation should not be taken literally, since what is meant is just that the truth properties of the premises and the truth property of the conclusion (all possibly different) covary in the right way.…”

“…37 For matter of space, an extensive discussion of the relation between the preservation problem of mixed inferences and the uniformity problem of valid inferences is left to a different work. (reference omitted) 38 This blocks the strategy proposed in Gamester (2018). 39 Alternatively, one might try to avoid generic truth by exploiting only one area specific truth property.…”

Alethic Pluralism and Logical Form

“…As such, for any sentence, the right‐hand side of the relevant definitional biconditional will be of the same logical form as the sentence itself, but attributing T A to its atomic components. (Gamester 2019, 40)…”

“…A second shortcoming arises from Gamester’s recipe for generating clauses of the theory: “for any sentence [of the object language], the right‐hand side of the relevant definitional biconditional [in the metalanguage] will be of the same logical form as the [object language] sentence itself, but attributing T A to its atomic components” (Gamester 2019, 41. ).…”

“…Will Gamester (2019) has proposed a solution to the problem for strong pluralists. On his approach, 'true' designates different properties for sentences with different logical forms.…”