Abstract

This paper criticizes the dominant approaches to presupposition projection and proposes an alternative. Both the update semantics of Heim and the discourse representation theory of van der Sandt have problems in explicating the presuppositions of disjunctions. Moreover, Heim's approach is committed to a conception of accommodation that founders on the problem of informative presuppositions, and van der Sandt's approach is committed to a conception of accommodation that generates over-interpretations of utterances. The present approach borrows Karttunen's idea that instead of associating presuppositions with sentences, we should define the conditions that contexts must meet in order to satisfy-the-presuppositions-of a sentence. However, in place of Karttunen's conception of contexts in terms of common ground, the present theory substitutes a conception of contexts as objective entities that are independent of the attitudes of the interlocutors. Contexts, so conceived, may be defined as containing sets of relevant possibilities. This allows us to define the conditions under which a context satisfies-the-presuppositions-of a disjunction.