Grice's principles and game theory

The study of languages (see Levinson, 1983) is traditionally divided into three domains: syntax, semantics, and pragmatics. Syntax is the study of language as a collection of symbols detached from their interpretation. Semantics studies the rules by which an interpretation is assigned to a sentence independently of the context in which the sentence is uttered. This chapter deals with the domain of pragmatics.

Pragmatics examines the influence of context on the interpretation of an utterance. An “utterance” is viewed as a signal which conveys information within a context. The context comprises the speaker, the hearer, the place, the time, and so forth. How the hearer views the intentions of the speaker and how the speaker views the presuppositions of the hearer are relevant to the understanding of an utterance. Thus, in game-theoretic terms, the way in which an utterance is commonly understood may be thought of as an equilibrium outcome of a game between speakers of a language.

To illustrate the type of phenomena explained by pragmatics, consider the following natural language conversations:

Example 1: A telephone conversation between A at home and his friend B, calling from a telephone booth:

1. A: “B, I am about to go for a walk. What is the weather like outside?”

2. B: “It is not raining heavily now.”

Normally, A concludes from B's statement that it is raining but not heavily.