On the Notion of Contrast in Information Structure and Discourse Structure

The idea of contrast plays an important role in the analysis of information structure and discourse structure. There is, however, some confusion as to what is meant by the notion of contrast. First, focus in general is held to establish a kind of contrast. Moreover, there is the notion of contrastive focus and of contrastive topic. Finally, English but is assumed to establish a discourse relation of contrast. In this paper contrastive phenomena in information structure and discourse structure are investigated with respect to the question of what they have in common and how they interact. The resulting picture is surprisingly systematic. First, there is contrast in the sense of similarity plus dissimilarity, which is the source of the contrastiveness of focus in general and is also a prerequisite for any type of coordination. On top of this, we find two varieties of exclusion. The first one results in substituting one item for another one and is realized by contrastive focus and also by the correction use of but. The second one excludes items occuring in addition and is realized by exclusive adverbs such as only and also by the contrast use of but.