Optimal Interpretation for Rhetorical Relations

This paper explores the use of a simple and computational optimality theoretic pragmatics (OT pragmatics, OTP) to the analysis of the rhetorical structure of texts. It introduces this variant of OTP briefly and then shows that it can be applied to explain coherence, rhetorical relations, discourse trees and context dependence using the occasional extra premiss. It thereby improves on existing accounts by reducing rhetorical structure to general pragmatics. It also contributes to the computational problem of inferring rhetorical structure by giving more structure to the inference processes involved, though it is as dependent on better ways of estimating semantic plausibility as any other system. 1 Optimality Theoretic Pragmatics Optimality theory (OT) is a natural environment to formalise pragmatics. It gives an account of defaults that is simpler than competing ones and defaults are the bread and and butter of pragmatics. While other formal accounts of pragmatics can likewise exploit the use of defaults in simplifying axioms, the OT framework forces their expression as a small set of very general principles which are applicable throughout pragmatics and thus prevents the development of accounts which only work for isolated phenomena. In this way, whatever one states about e.g. rhetorical structure will have its repercussions on presupposition projection or the derivation of implicatures. In fact, the proposal of this paper on rhetorical structure developed in an organic way by progressive abstraction from the influential account of presupposition projection of Heim (1983) and van der Sandt (1992). It was also heavily influenced by other work on OT pragmatics like Blutner (2001), Beaver (2004), Jäger (2003) and Mattausch (2001a) as well as by the pioneering approach of Hendriks and de Hoop (2001). Calling the system OT pragmatics merely means that it is conceived as a system of strictly ordered soft constraints. Both the constraints and their ordering should be universal. It will be argued below that it is identical to a constraint system that would give explanations for communicative behaviour of other subjects, itself a special case of the notion of explanation of natural events. This means that the constraint system as such is not part of the development of human languages and may operate just as well in other species, provided joint attention to common goals and common questions can be assumed. It can even be argued that it is not OT at all,