Presupposed Ignorance and Exhaustification

Abstract

This paper investigates the interactions between presuppositions and scalar implicatures. We start our discussion with a previously undiscussed puzzle which we call presupposed ignorance and offer a preliminary account of it. We then claim that certain types of interactions between presuppositions and scalar implicatures, namely those involving Strawson-decreasing presupposition triggers and weak scalar items, can be understood as special cases of presupposed ignorance. But we also point out that this cannot be the whole story, as it runs into problem with examples involving Strawson-increasing presupposition triggers with weak scalar items. To counter this problem, we propose that the mechanism of scalar strengthening, namely the exhaustivity operator (EXH), interacts with the mechanism responsible for presupposed ignorance in an intricate manner, thereby giving rise to the complex empirical patterns we observe.