Lexical Cohesion And Discourse Topics

Topic is an important and controversial term in the field of discourse analysis. Topic study in linguistic field started from the middle of the 19th century, and has developed rapidly in the 20th. The studies on topic can be categorized into two types: grammatical studies and functional studies. Grammatical studies, represented by Li & Thompson (1976), treat topic as a structural element of a sentence; while the latter study topic on the basis of discourse. Functional studies can be further divided into two types, the linear studies and hierarchical studies. Scholars belong to the linear studies are Keenan & Schieffelin (1976), and Goutsos (1997); those belong to hierarchical studies are van Dijk(1977a, b), and Chafe (1994).Different scholars study from different perspectives. This thesis adopts van Dijk's"Macro-structure theory"as one of its theoretical basis. According to van Dijk (1977a, b), discourse topic is different from sentential topic, it is a complex proposition entailed by a sequence of discourse or a whole discourse. In a discourse, there is a hierarchical not a linear topic structure, which is formed by the general topic and its subtopics of different levels. van Dijk theorized his study of discourse topics in terms of macrostructure, and proposes several operation rules to derive the macrostructure from a text.van Dijk (1977b) treats language as a semiotic system containing three branches: syntax, semantics, and pragmatics. A text should express the prepositional meaning and the contextual meaning simultaneously through its syntactic structure. As a discoursal concept, topic(s) studied by van Dijk only reflect the prepositional meaning, so it is incomplete. In his illustration of the working process of the macro-rules, van Dijk only selects some structurally and semantically simple texts as his examples, and also this process simply turns a subjective conclusion into a group of prepositional expressions.van Dijk holds that there are more than one topic in a text, and these topics form...