In this and the next three chapters I will analyze the concepts which I consider fundamental to the study of information structure. These concepts are: (i) propositional information and its two components presupposition and assertion (Chapter 2); (ii) the identifiability and activation states of the representations of discourse referents in the minds of the speech participants (Chapter 3); (iii) the pragmatic relations topic (Chapter 4) and focus (Chapter 5). Many of the observations in these chapters have been made by other linguists before me, and I will acknowledge my predecessors whenever possible. Other portions, I believe, contain new insights, such as the analysis of the pragmatic relations “topic” and “focus” and of the relationship between the two. In particular, what I believe is new in my treatment, and what prompts me to call it loosely a “theory,” is the idea that an account of information structure must include all three of the sets of concepts listed above and must explain how they relate to each other.

The universe of discourse

I will begin by sketching a simple model of the universe of discourse. In this model, I presuppose the primacy of spoken language over other forms of linguistic communication (see Lambrecht 1986b: Ch. 1). I will therefore always refer to “speakers” and “hearers” (or “addressees”) not to “writers” and “readers.”