Pragmatic Presupposition In Discourse Coherence

The notion of presupposition was first introduced to the field of linguistics by German philosopher Frege in 1892. Ever since that, it has been a focal topic in linguistics. Since 1970s', linguists have had a heated discussion on whether presupposition is semantic or pragmatic. Because of its defeasibility and the projection problem, more linguists are liable to take presupposition as a pragmatic phenomenon with characteristics of felicity and mutual knowledge. As presupposition is realized by language, the study of presupposition should also be carried out in language in use. Previous studies of presupposition are mainly conducted at the sentence level, while few words are about that at the discourse level. Functionalism persists in studying language in use, and the systematic functional grammar represented by Halliday could be by far the most comprehensive school. In Cohesion in English published in 1976, Halliday and Hasan have founded the cohesion theory. They claim that cohesion is what makes a text from non-text. In addition to the texture which ensures the discourse coherence, Hasan views that structure unity also plays a role in discourse coherence and proposes the generic-structure potential theory (GSP) in Language, Context and Text in 1985. Since both the presupposition study and the systematic functional grammar emphasize the importance of discourse concept and context in the linguistic study, it is quite feasible to regard the study of presupposition in discourse as an interface between pragmatics and the systematic functional grammar.This thesis has been done on the bases of the cohesion theory and the GSP theory within the framework of the systematic functional grammar. The objective of this thesis is to study the role of pragmatic presupposition in the process of constructing coherent discourse from the two aspects of texture and structure unity. The author of the thesis holds the point of view that presupposition is a set of potentials. Only when a potential is consistent with the context and coherent with the assertions before and after it, can we say it is the presupposition in that specific discourse. The pragmatic presupposition in the thesis is of linguistic and extra-linguistic types. Those linguistic presuppositions which are triggered by words and constructions contained in a discourse are external and explicit on the surface structure. By being extra-linguistic, we mean that presuppositions shared by both the addresser and addressee in advance of the communicating process are internal and implicit at the deep structure. The so-called semantic presupposition is the presupposition at the lexico-grammatical level, belonging to the category of pragmatic presupposition. Cohesive device is one way of being texture. Kinds of devices nicely presuppose the existence of information in the discourse. Hence, all those five cohesive devices are naturally external presuppositions shown at the lexico-grammatical level. Register consistency is the other sufficient and necessary condition for being texture. Register consistency indicates that context and text can predict from each other. What can be predicted from the register consistency must have been shared as the mutual known knowledge, which is in fact the realization of implicit presupposition. Structure unity in discourse is made up of local coherence and global coherence. In the thesis, we will analyze the functions of pragmatic presupposition in discourse structure from the perspectives of both the bottom-up and the top-down. According to Halliday, clause is the basic unit in discourse, and sentence is a clause complex. Local coherence here refers to the coherence realized by presuppositions conveyed in groups and phrases within a clause complex. As for the global coherence, it includes on the one hand coherence realized above the clause complex and the generic structure unity under the GSP theory on the other hand. Both explicit and implicit presuppositions assist in achieving structure unity.The whole thesis is composed of five parts. The author first has a short review of presupposition study, then points out the limits of the previous studies and proposes a functional approach to the presupposition study in the thesis and the organization of the thesis accordingly. Chapter one is a review of the theoretical backgrounds. The notion of pragmatic presupposition and its characteristics are generalized first. Then three theories used to explain pragmatic presupposition as well as the cohesion theory and the generic structure potential theory which concern about discourse are introduced. Chapter two, on the basis of the above theoretical backgrounds, analyzes the feasibility of studying functions of pragmatic presupposition at the discourse level from the perspective of discourse coherence. In chapter three, we interpret how pragmatic presuppositions contribute to discourse coherence in four Chinese texts from the texture and structure aspects. The last part is the conclusion of the thesis. The objective and the innovation of the present study are summarized in it, and further study is suggested.