Formal and Functional Explanation

Formal explanations and functional explanations are often taken to be diametrically opposed modes of accounting for linguistic phenomena. However, the two are complementary, rather than being irrevocably in opposition to each other. One can be a ‘formal linguist’ and a ‘functional linguist’ at the same time, without there being any contradiction. Formalism and functionalism represent poles of a timeless dichotomy, each expressing a valid way of representing reality. Both poles can only be regarded as deeply right, and each needs the other because the full axis of the dichotomy operates as a lance thrown through, and then anchoring, the empirical world. If one pole ‘wins’ for contingent reasons of a transient historical moment, then the advantage can only be temporary and intellectually limited. (Gould 2002: 312) Internalist biolinguistic inquiry does not, of course, question the legitimacy of other approaches to language, any more than internalist inquiry into bee communication invalidates the study of how the relevant internal organization of bees enters into their social structure. The investigations do not conflict; they are mutually supportive. In the case of humans, though not other organisms, the issues are subject to controversy, often impassioned, and needless. (Chomsky 2001: 41) 1. The great rhetorical divide in linguistics Perhaps the greatest rhetorical conflict that exists (and has long existed) among the linguists of the world is between those who practice some variety of ‘formal linguistics’ and those who practice some variety of ‘functional linguistics’. The former advocate formal explanations of linguistic phenomena and the latter functional explanations. But I have carefully chosen the wording ‘rhetorical conflict’, since the principal purpose of this chapter is to argue that there is no inconsistency in advocating (and practicing) both modes of explanation. A major impediment to the task of characterizing and evaluating the two explanatory strategies is that the very words ‘formal’ and ‘functional’ are used differently by different linguists. For some an explanation is ‘formal’ if and only if it accords center stage to formal structure (as opposed to, say, discourse). Such is the use of the term in mainstream syntactic theory, namely the Principles-andParameters (P-and-P) approach (Chomsky 1981) and those models directly antecedent and subsequent to it (Chomsky 1973; 1995). For others, particularly those who work in constraint-based approaches like Head-Driven Phrase Structure Grammar (Sag, Wasow, and Bender 2003) and Lexical-Functional Grammar (Bresnan 2001), an explanation is ‘formal’ if and only if the theory is formalized in minute detail. So when Pullum (1989) challenges the right of Pand-P to call itself a ‘formal approach’, he has the latter sense of the term ‘formal’ in mind. We find analogous problems with the term ‘functional’. For some an explanation is ‘functional’ if and only if its explanans are external to grammar per se. Most self-described ‘functionalists’ in North America use the term ‘functional’ in that way. But for others, it is sufficient to describe an explanation as ‘functional’ if it accounts for the functioning of the elements of the grammatical system internally — that is, with respect to each other. For example, Andre Martinet, a prominent French linguist active between the 1950s and 1970s could entitle one of his books A functional view of language (Martinet 1962), when much of its content was devoted to illustrating purely structural oppositions