Dipping randomly into another one of Roy Peter Clark's Glamour of Grammar essays ("What the Big Bopper Taught Me About Grammar", 5/8/2008), I found this curious piece of revisionist intellectual history:
In our common culture, grammar has taken on at least three sets of meanings and associations. It still refers to the etiquette of writing and reading, the conventions that allow us to create a standard written English, the technical term for which, according to critic John Simon, is "grapholect."
This view of grammar is sometimes called "prescriptive," which is how I came to understand in 1959 (at the age of 11) that, when the Big Bopper sang "… but baby I ain't go no money, honey," he was using language in a way that would have gotten his ass kicked by Sister Catherine William. [...]
Then, of course, along came "descriptive grammar," a movement that had the unmitigated gall (why is gall always unmitigated?) to sneak "ain't" in the dictionary, a discipline of language that could take into account the Big Bopper's nonstandard usage, including that surely double negative.
Underpinning this rebellion against Emily Post conformity was something called "transformational" or "generative" grammar, described by scholars such as Noam Chomsky, before he became a political critic and darling of the left.
This explanation evokes another common collocate for unmitigated, namely nonsense.
Neither Noam Chomsky nor generative grammar deserve any credit — or blame — for the concept of descriptive linguistics. In this matter, his generation of linguists simply followed the approach of their teachers, and their teachers' teachers, well back into the century before Noam was born.
The first clue that something has gone badly wrong with Prof. Clark's intellectual history is the business about descriptive grammar having the gall to "sneak ain't in [sic] the dictionary". This is a reference to the controversy over Webster's Third. This work was published in 1961, but the entry for ain't was probably written about a decade earlier, while Noam Chomsky was an unknown graduate student at the University of Pennsylvania. And the editorial policy of Webster's Third was set by Philip Babcock Gove, whose ideas were formed at Columbia, Harvard and Dartmouth in the 1920s and 1930s, following a tradition of English lexicography established more than century earlier:
Critics of the Third Edition believed that it was the responsibility of a dictionary to serve as a standard of correctness, to tell users what was right and what was wrong … Gove said that the job of the dictionary was to describe how people used language, not how they should use it, echoing the views expressed by Dean Richard Chevenix Trench in two famous papers on the deficiencies of English dictionaries. The papers (both read to the Philological Society in November 1857) greatly influenced the planning of the Oxford English Dictionary and English lexicography generally. Trench … called the lexicographer "an historian [of the language], not a critic" and explicitly warned his colleagues against repeating the mistake of the French Academy, which had sought to fix the language and prescribe a standard of correctness for the nation. [Herbert C. Morton, The Story of Webster's Third: Philip Gove's Controversial dictionary and Its Critics, CUP, 1994; p. 7]
One of Prof. Clark's better ideas is to "Look it up in the OED!". If he'd followed his own advice in this case, he'd have discovered that the OED's sense 3.b. for descriptive
Linguistics. Describing the structure of a language at a given time, avoiding comparisons with other languages or other historical phases, and free from social valuations; as in descriptive grammar, linguistics, etc. (Opp. normative, prescriptive, historical; cf. SYNCHRONIC a.)
has citations back to 1888, long before Noam's birth:
1888 H. A. STRONG tr. Paul's Princ. Hist. Lang. i. 2 Descriptive Grammar has to register the grammatical forms and grammatical conditions in use at a given date within a certain community speaking a common language.
1927 Mod. Philol. Nov. 217 (heading) Descriptive linguistics. Ibid. 218 Today descriptive linguistics is thus recognized beside historical, or rather as precedent to it.
1933 JESPERSEN Ess. Eng. Gram. i. 19 Descriptive grammar..aims at finding out what is actually said and written by the speakers of the language investigated.
1947 E. H. STURTEVANT Introd. Ling. Sci. vi. 51 Descriptive linguistics forms the basis for historical linguistics. Ibid. 53 Most of our school grammars must be classed as descriptive.
1953 J. B. CARROLL Study of Lang. ii. 16 Several Greek grammarians, notably Dionysius Thrax, Apollonius Dyscolus, and Herodian, developed descriptive grammars of Greek.
Ibid. 19 The European linguist who best formulated the methodology of descriptive linguistics..was Ferdinand de Saussure.
Beyond the merely terminological issue, Prof. Clark must surely know that the concept of grammar as a description of usage — though perhaps geographically, socially and culturally specific usage — goes back several thousand years; and that Horace in particular famously asserted that usage controls "the law and the standard of language" (et ius et norma loquendi).
And if Prof. Clark had thought for a moment before banging out this essay, I bet he would have remembered that quotation — after all, William Safire wrote a book entitled "In Love with Norma Loquendi". The problem, thoughout these Glamour of Grammar essays, seems to be precisely that Clark writes before he thinks — and doesn't think after he writes, either. He apparently doesn't care whether or not what he writes is true, or even coherent, as long as it sounds good to him.
In that sense, his thoughts on this topic — or at least the samples that I've seen so far — are neither prescriptive grammar nor descriptive grammar, but rather, in the technical sense of the word, bullshit grammar. And while I never met Sister Catherine William, I bet that she was even less tolerant of bullshit than she was of double negatives.