Lies are assertions and presuppositions are not

Abstract

ABSTRACT Most philosophers agree that lies are assertions. Most also agree that to presuppose information is different from asserting it. In a series of papers, Viebahn [2020. “Lying with Presuppositions.” Noûs 54 (4): 731–751; “The Lying-Misleading Distinction: A Commitment-Based Approach.” Journal of Philosophy 118 (6): 298–319], along with an empirical study in Viebahn et al. [2021. “Can a Question be a lie? An Empirical Investigation.” Ergo 8 (7): 175–217], has recently argued that one can lie with presuppositions, and therefore one can assert that p by presupposing that p. The latter conclusion is a rejection of a cornerstone of modern philosophy of language and linguistics, and as such we should require strong reasons for accepting it. I argue here that the reasons for thinking that presuppositions can be lies are too weak to motivate giving up either the view that lies are assertions or the traditional distinction between presuppositions and assertions.