On a Condition of the Coherence of Texts

Let us accept the following working definition of a coherent text or discourse, which is compatible with the intuitive understanding of these terms. A discourse is a sequence of utterances Si, 82, ... Sn, such that the semantic interpretation of each utterance Si (for 2 ^ i ^ n) is dependent on the interpretation of the sequence Si..., Si_i. In other words, an adequate interpretation of an utterance occurring in a discourse requires the knowledge of the preceding context. Such a definition of discourse applies equally well to everyday conversations, lectures and literary or scientific texts. Let us accept also the view that the semantic interpretation of any utterance is the set of consequences or conclusions that can be drawn from that utterance. We shall not explain here how we understand the term "set of consequences" in relation to a natural language utterance, as this will be discussed later in this paper. It may, however, be worthwhile to emphasize here that such an approach is intuitively clear, for it is hard to disagree that if someone understands a given utterance, he is capable of drawing the conclusions that follow from it, and vice versa. The definition given above is compatible with an assumption that has to be made by any speaker, addresser of a message, or author of a text