Pragmatic focuses on the way in which people communicate with each other. It is concerned with the use of language to convey information or to make a statement, as well as with non-linguistic features such as body posture and facial expressions, gestures, eye contact, voice tone and volume. In addition, pragmatics is interested in the context in which a word or phrase is used and how that can affect its interpretation. For example, a sentence may be interpreted differently in different social situations because of how the participants expect the speaker to behave or what they already know about the speaker.
In practice, pragmatics is a broad field of study. There are those who see it as a philosophical project in Grice’s tradition, others who focus on its interaction with grammar and still others who consider it an empirical psychological theory of utterance interpretation. It is a common belief that pragmatics includes a number of concepts which, taken together, form the whole of communication: what speakers mean when they use certain words and the particular circumstances under which those words are uttered; how the ambiguity and indexicality of certain phrases can be resolved; and what kind of inferences — possibly by induction or inference to the best explanation or Bayesian reasoning — are necessary in order to determine what an utterance means.
One of the fundamental concepts in pragmatics is that of presupposition. The idea here is that the meaning of an utterance can be derived, at least to some degree, from the things that it is assumed to refer to. This is distinct from referentialism, which requires that every utterance possesses an unambiguous reference to a particular object or event. For example, if the utterance is “It is obvious that Hesperus and Phosphorus are two names for the same planet,” then according to referentialism this merely expresses the fact that “Hesperus” and “Phosphorus” are both visible in the eastern sky.
A number of different theorists have interpreted the notion of presupposition. Minimalists see it as a part of semantics, whereas hidden indexical theorists view it as a pragmatically determined aspect of an utterance’s content. These theorists differ over how much of a given utterance’s content is determined by presuppositions, with minimalists restricting it to those parts which can be determined by a strict analysis of grammar and the logical form of the resulting proposition. Other theorists, however, take a broader approach and include any contextually relevant information that can be derived from linguistic features, or which can be worked out by some kind of inference (perhaps induction, inference to the best explanation, or Bayesian reasoning). This is the approach taken by Critical Pragmatics, and it is also broadly supported by speech act theory. Narrow context is usually defined as the list of parameters required to interpret basic indexicals, such as speaker, time and place. Wide context involves other information, such as ongoing topics of conversation and causal and informational chains.