Enthymemes in Dialogue: A micro-rhetorical approach

Abstract: In dialogue we frequently present arguments which are based on commonly accepted non-logical inferences. In rhetorical theory, this type of argument is called an enthymeme, and a pattern of reasoning that it is based on is called a topos. The main purpose of this thesis is to investigate the role that enthymemes play in natural language dialogue. The analyses focus on authentic dialogue material, and informal theories from linguistics and language philosophy are combined with formal theories in what can be con- sidered a micro-rhetorical approach. This approach focuses on function in language, and the idea is that linguistic phenomena of the type studied by linguists are the micro-end of rhetorical phenomena. Formalisation is an important method in this thesis. The information state of a dialogue par- ticipant is modelled as a dialogue gameboard showing her current take on the dialogue and the cognitive resources currently activated. The formalisa- tions are done in the semantic frame work Type Theory with Records. The first part of this thesis focuses on the linguistic and philosophical context of enthymeme and topos. In chapters 3–4 the formal model is developed, and in chapter 5 it is applied to a number of cases. Some of the main con- tributions of this thesis are that it points out that underpinning patterns of resoning are necessary to make pragmatic inferences, and suggests a pre- cise way of formalising these patterns. Also, the concept of Accommodation is associated with enthymemes and topoi. Accommodation of enthymemes explains how agents can infer some types of rhetorical relations based on ac- cessed topoi. Accommodation of topoi o↵ers an explanation to some types of misunderstandings as well as a way of looking at learning of new topoi.