In the functional paradigm, […], a language is in the first place conceptualized as an instrument of social interaction among human beings, used with the intention of establishing communicative relationships. Within this paradigm one attempts to reveal the instrumentality of language with respect to what people do and achieve with it in social interaction. A natural language, in other words, is seen as an integrated part of the communicative competence of NLU [natural language user]. […]. From the functional point of view, then, linguistics has to deal with two types of rule systems, both ratified by social convention: (i) the rules which govern the constitution of linguistic expressions (semantic, syntactic, morphological, and phonological rules); (ii) the rules which govern the patterns of verbal interaction in which these linguistic expressions are used (pragmatic rules). Rule system (i) is seen as instrumental with respect to the goals and purposes of rule system (ii): the basic requirement of the functional paradigm is that linguistic expressions should be described and explained in terms of the general framework provided by the pragmatic system of verbal interaction. And, […], verbal interaction itself must be seen as integrated into the higher cognitive functions of NLU.
- Dik (1989), Pag. 3-4

This [functional] paradigm defines the basic “philosophy” which underlies FG [Functional Grammar].
- Dik (1989), Pag. 7