Relevance and lexical pragmatics

A common problem for linguists, philosophers and psychologists is that linguistically specified (‘literal’) word meanings are often modified in use. The literal meaning may be narrowed (e.g. drink used to mean ‘alcoholic drink’), approximated (e.g. square used to mean ‘squarish’) or undergo metaphorical extension (e.g. rose or diamond applied to a person). Typically, narrowing, approximation and metaphorical extension are seen as distinct pragmatic processes with no common explanation: thus, narrowing has been analysed in terms of default rules (e.g. Levinson 2000), approximation has been treated as a type of pragmatic vagueness (e.g. Lewis 1983; Lasersohn 1999) and metaphorical extension is standardly seen as a case of maxim violation with resulting implicature (Grice 1989). I will propose a unified account on which narrowing, approximation and metaphorical extension are special cases of a more general pragmatic adjustment process which applies spontaneously, automatically and unconsciously to fine-tune the interpretation of virtually every word, and show how the notion of an ad hoc concept introduced by Barsalou (1987, 1992) might interact with a pragmatic comprehension procedure developed in relevance theory (Sperber & Wilson 1998; Carston 2002; Wilson & Sperber 2002) to account for a wide range of examples.