Truthmaker maximalism and the truthmaker paradox

Abstract

According to truthmaker maximalism, each truth has a truthmaker. Peter Milne has attempted to refute truthmaker maximalism on mere logical grounds via the construction of a self-referential truthmaker sentence M “saying” of itself that it doesn’t have a truthmaker. Milne argues that M (similar to a Godel sentence and different from a paradox-generating Liar sentence) turns out to be a true sentence without a truthmaker and thus provides a counterexample to truthmaker maximalism. In this paper, I show that Milne’s refutation of truthmaker maximalism does not succeed. In particular, I argue that the notion of truthmaker meets two structural principles which, if added to a formal language of a theory (that allows for diagonalization), are already sufficient to produce a provable contradiction—a contradiction that gives rise to a socalled “Truthmaker paradox”. I also address the question of how to possibly resolve the Truthmaker paradox. I thereby show that the Truthmaker paradox, just as the strengthened Liar paradox, yields a “revenge problem” for paracomplete theories and might lead to triviality for Priest’s dialetheist account LP if the notion of truthmaker is defined as a certain semantic predicate within LP. But regardless of how one tries to cope with the Truthmaker paradox, this paradox is surely interesting in its own right. However, its significance is completely orthogonal to the question of whether truthmaker maximalism is a philosophically sound view.