Chomsky and the North American Descriptivists

Although the influence of his mentor Zellig Harris is evident in much of Chomsky’s early work, his books Syntactic Structures and Aspects of the Theory of Syntax, which followed in 1965, marked a decisive break with the Descriptivists in a number of respects. Where the Descriptivists had stressed discovery procedures, data collection methodology and the analysis of corpora, Chomsky saw the linguist’s goal as the production of grammars to ‘generate all and only the grammatical sentences of a language’.

Such a device would describe a potentially infinite number of sentences from finite means, i.e. it had to allow for recursive sentences of the ‘House that Jack built’ kind (‘This is the cat that ate the rat that ate the corn’, etc.), which could in theory, if not in practice, be extended indefinitely. It would also go beyond the Descriptivists’ goal of accounting for a finite corpus of linguistic data, which would reach only the first of three levels of adequacy – observational adequacy – in Chomsky’s eyes. To reach the next level, descriptive adequacy, a grammar would have to account not only for the observed data within a corpus but also for a native speaker’s intuitions about grammaticality, or his/her competence. Native speakers of a language, Chomsky argued, are able to judge the grammaticality of a sentence that they have never heard before, irrespective of whether it is meaningful. His most famous example is cited below:

1 Colorless green ideas sleep furiously

2 Furiously sleep ideas green colorless

He claimed that (1) is perfectly grammatical, in spite of the fact that it is nonsensical and had probably not been uttered before. (While that was probably true in 1957, it has been a staple of linguistics textbooks ever since – I’d have felt I was letting you down if I had omitted it here.) An English speaker will read it confidently and with normal sentence intonation, whereas its reverse (2) is ungrammatical, and would be read haltingly as a list of words.

Grammaticality for Chomsky is not, therefore, based on semantics (i.e. meaning): nor, indeed, is it based on statistical probability. Completing the sentence frame ‘I saw a fragile_________’ with the word ‘whale’ or ‘of’ results in both cases in sentences with a zero probability of occurrence in English, yet native speakers accept ‘I saw a fragile whale’ as grammatical, while rejecting ‘*I saw a fragile of’.