Assertions from discourse structure

Abstract

As part of an ongoing study of discourse structure of natural texts, we have identified a particular class of propositions that affect the hearer's perception of the coherence and communicated content of texts. As an example, if the text (spoken in a suitable situation) is:I'm hungry. Let's go to the Fuji Gardens.then the most natural interpretation is that the Fuji Gardens is a restaurant at which the speaker would like to eat with the hearer. The text is heard as exhibiting a problem-and-solution structure. Consequently, we can say that there is a proposition which says that there is a relation between the two sentences. In this case, going to the Fuji Gardens (partially) solves the hunger problem.The solutionhood construct is one type of re/ational propositions. Note that the proposition about solutionhood is not stated explicitly in the text.Although phenomena resembling relational propositions have been recognized, there is no widely accepted explanation of how they arise from text. This paper characterizes relational propositions and presents a theory of discourse structure to explain them. In this Rhetorical Structure Theory (RST), relational propositions arise in direct correspondence to particular elements of the structure of a discourse.We present Rhetorical Structure Theory progressively during analysis of a published, two-paragraph political advocacy text. The text involves substructures for informing, giving evidence, conceding, requesting an action, justifying a presentation, asserting conditionally, and others.The two elements that form the basis for this paper, relational propositions and Rhetorical Structure Theory, have both been described in more detail elsewhere. The explanatory relation between them, however, has not [Mann & Thompson 83, Mann 84].[Mann & Thompson 83] examines various other theoretical constructs, including implicature, presupposition and indirect speech acts, to see whether they account for the textual properties of relational propositions. It concludes that these constructs do not account for them. The paper also discusses relationships between relational propositions and the work of Grime& Hobbs, van Dijk, Martin, Longacre, Beekman and Callow, and it includes analyses of several texts.