Presupposition, Implicature, and Context in Text Understanding

Abstract The roles which presupposition and implicature play with respect to what is asserted by a text and to its context are examined as a part of the process of text understanding. This process involves constructing and updating the representation of the context. Assertion, implicature, and presupposition can be described as three different ways in which changes in the representation of the context are induced. On the basis of such a description, it is claimed that, contrary to most of the literature on the subject (in which presupposition and implicature seem not to be allowed to coexist without being seen as identical), there are good reasons to consider presupposition and implicature as distinct. For example, a presupposition may be such even if its content has already been asserted, while this would make an implicature useless, and therefore prevent it from arising.