Maximize Presupposition and Gricean reasoning

Recent semantic research has made increasing use of a principle, Maximize Presupposition, which requires that under certain circumstances the strongest possible presupposition be marked. This principle is generally taken to be irreducible to standard Gricean reasoning because the forms that are in competition have the same assertive content. We suggest, however, that Maximize Presupposition might be reducible to the theory of scalar implicatures. (i)First, we consider a special case: the speaker utters a sentence with a presupposition p which is not initially taken for granted by the addressee, but the latter takes the speaker to be an authority on the matter. Signaling the presupposition provides new information to the addressee; but it also follows from the logic of presupposition qua common belief that the presupposition is thereby satisfied (Stalnaker, Ling Philos 25(5-6):701-721, 2002). (ii) Second, we generalize this solution to other cases. We assume that even when p is common belief, there is a very small chance that the addressee might forget it ('Fallibility'); in such cases, marking a presupposition will turn out to generate new information by re-establishing part of the original context. We also adopt from Raj Singh (Nat Lang Semantics 19(2):149-168, 2011) the hypothesis that presupposition maximization is computed relative to local contexts-and we assume that these too are subject to Fallibility; this accounts for cases in which the information that justifies the presupposition is linguistically provided. (iii) Finally, we suggest that our assumptions have benefits in the domain of implicatures: they make it possible to reinterpret Magri's 'blind' (i.e. context-insensitive) implicatures as context-sensitive implicatures which just happen to be misleading.