Evidential scalar implicatures

This paper develops an analysis of a scalar implicature that is induced by the use of reportative evidentials such as the Cuzco Quechua enclitic = si and the German modal sollen. Reportatives, in addition to specifying the speaker’s source of information for a statement as a report by someone else, also usually convey that the speaker does not have direct evidence for the proposition expressed. While this type of implicature can be calculated using the same kind of Gricean reasoning that underlies other scalar implicatures, it requires two departures from standard assumptions. First, evidential scalar implicatures differ from the more familiar scalar implicatures in that they do not turn on the notion of informativeness but on the notion of evidential strength. Second, the implicature arises on the illocutionary level of meaning. It is argued that a version of Grice’s maxim of quantity in terms of illocutionary strength can account for this evidential scalar implicature as well as for the more typical scalar implicatures. The account developed also proposes some revisions to the taxonomy of speech acts and suggests that the sincerity conditions of assertive speech acts contain an evidential sincerity condition in addition to the belief condition standardly assumed.