Pragmatics is the study of language in context, and the ways that one and the same sentence can express different meanings or propositions from context to context. This branch of philosophy looks at how this happens, including the effects of ambiguity, indexicality and conversational implicature, as well as various other factors. It is also concerned with the interaction between semantics and pragmatics, as well as between language and other elements of a communicative act. Pragmatics is a broad discipline, and there are many different approaches. Some philosophers see it as a philosophical project in the spirit of Grice, others focus on its interaction with grammar, and still others look at the way people actually use language.
The concept of the context of an utterance has been a central issue in pragmatics since Frege’s “Uber Sinn und Bedeutung” (1892). Some authors have drawn a distinction between linguistic and extra-linguistic context. Others have argued that this is not a valid distinction, as contextual elements can influence the interpretation of an utterance even if they are not directly incorporated into its grammatical structure.
Other scholars have taken the view that there is a distinction between conventional or literal meaning and non-literal meaning, although this has sometimes been qualified to be a continuum rather than a two-sided dichotomy. It is also common to treat figurative and metonymic meanings as pragmatically different from literal and ironic meanings, although there are varying views about how far the differences go.
One of the most important practical issues in pragmatics is how to decide which meaning or set of meanings an utterance has, and how to evaluate its effectiveness. In some cases, this involves resolving ambiguity or indexicality, while in other cases it is a question of whether the utterance conveys its intended intention. This is particularly the case when a speaker uses an idiom, a figure of speech that conveys a figurative meaning, but the meaning of which is not directly encoded in the lexicon of the language.
A related issue is the problem of reference resolution, which determines whether an utterance refers to a specific entity or to a generic one. Reference resolution is a critical issue for natural language processing, which attempts to create computer systems that more closely approximate human language and information processing abilities.
The pragmatics of communication is also a central issue in the philosophy of language, particularly when dealing with questions of truth, falsity and inference. For example, in the case of a lie, the question is not just what the speaker meant to say but what his or her actual intention was. This issue is a fundamental one in the philosophy of language and has implications for social and political life. A number of philosophical perspectives on this issue have been developed, including those of Wittgenstein, Chomsky and John Searle. The latter has focused on the idea that there is no such thing as a logically unambiguous statement, and has developed an approach to this problem called conversational implicature, which is used in some legal systems.