There are many dead languages in the world; most are aboriginal, but many are civilized. Sumerian is a dead language; no one reads it except to translate from it. But Latin is not a dead language. No one writes in Sumerian—and what you wrote in Sumerian, if you had that whim, would be philological caprice, not real Sumerian. But with diligence anyone can learn to write Latin; and what they write is real Latin, because Latin has been preserved and immortalized by the prescriptions of its grammarians, who sheared their language from the Tiber by making it answerable only to written, explicit, portable, unowned rules, and therefore fit to receive the genius of all peoples and ages.
There is an English-language literature, not several streams of British and American and Commonwealth literature, and English is fit to be the universal and auxiliary language of commerce and science, only because of those grammarians, and that lexicographer, who trawled and netted its vagaries, who indefatigably caught and named and pinioned and catalogued until a whole language, fit for any purpose, was anatomized and exhibited.
The English language is still vital, and thus changeful on vulgar tongues, and among scientific explorers who must quickly get over the business of giving names to their new worlds; but most of these words will die, becoming quaint or obsolete. While they live, they may serve probation to become part of the language; but likelier, they will never be cut free from their contexts, and if they come to be written at all it will be only for color.
The Latin model is not ideal for English—nor for Latin, whose grammar is modeled after Greek; but our Latinate grammar is not a cage; it is a trellis. It supports the whole structure of English literature. It is not an affected, alien imposition: it is, itself, the English language. It has not prevented English from fracturing, as is its nature—as was Latin's nature, Europe witnesses—but it has preserved over and above those dialects a true, nuclear English. I dare call it true because English as we know it is not the product of any natural development. English is an artificial language; a consciously and self-consciously made hybrid of Englisc, Norman French and Latin. The great writers and translators into our English, Mallory, Browne, Bacon, Burton, Florio, North, Urquhart, Sidney, Spencer, Shakespeare, did not use the English they found: they created the English we know. I do not believe that anyone in their time, even they, spoke as they write. But we speak their language, not a descendant of any of the argot-pidgin-creole-cant-jargon-lingoes (likely closer to Chaucer) that would have been heard in the London of their time.
Dialects, whatever the charm they have to linguists, cannot be entered into by outsiders. They presume and enforce a shared background, a particular geographic, racial, cultural economic set of coördinates. They are worthy of study; they are worthy of respect, as aspects of cultures; but, though they do not much endanger English, it is the function and duty of grammarians to cut them down, to make room for their successors. There will always be a new crop of dialects and jargons and a new harvest of what they have to offer English as such, which must then wither to make way for the next crop. English is in no danger from descriptivists and careless linguists who misapply instruments proper to study the creativity and forgetfulness of illiterate languages to literate ones—which are just as creative, but need never forget. English is stronger than its enemies; and because English is as immortal and universal as it is captured in books, English literature is being fed into by countries with nothing else but English grammar in common, and by the best minds of these countries, who know that what they write in their mother languages is only for their brothers and sisters; but what they write in English is for the world and forever.
As ever, it is the artist who knows the rules and breaks them knowingly; the fool who breaks them unknowingly; and the damn fool who neither mends nor defends their mistake, but protests its detection, as if we should sit and watch while they and their nuisance ilk pound a wedge to rive us from the continuity that English has enjoyed since Shakespeare. Now, Shakespeare was free with his language; but in every art the freedom of genius frames the rules for the rest. Anything which takes us further from Shakespeare deserves careful examination, and some period of quarantine.
English's rules are not perfect. Some are golden, the indispensable instruments of clarity (like keeping participle and subject in agreement); some are well-exampled, but questionable (they as a gender-neutral singular pronoun); some asinine, but somehow impossible to banish (aversion to the split infinitive or the hanging preposition—which one does best to carefully think about). But it is better to have bad rules among good ones than no rules. The case is rather like spelling reform. English spelling is so peculiar, so uniquely adapted for its needs—not as illogical as some imagine—that spelling reform poses a double danger.
1. Our spelling conceals from us how really diverse, especially in vowels, our dialects are. An accurate phonetic spelling of English would of necessity either become so formalized as to obviate its aim, or remain faithful to the sounds of English, and thus be slow to read. Orthographic convention distinguishes the command, "Marry merry Mary," from the assessment of Mary, that "merry Mary married," or of the ceremony, "Mary married merrily." Either we would have to be on constant guard against such ambiguities and uncertainties—every writer's spellings declaring their background—or adopt some single dialect, or commingling of dialects, as a standard source of spellings to be imposed on everyone else. Distasteful (æsthetically and patriotically, to this American) as it is to think of the mealy sounds of the King's English overlying all English literature—it is better than to think of seeing Shakespeare exhibited in print under the droning manufactured nowhere-dialect of the television anchor.
2. English orthography is so complex if it were not taught, trouble would not often be taken to learn it. Much would be transcribed; more would effectively be lost—whatever our age's critics, and public taste, did not see fit to preserve accessibly. What could we lose at the hands of a modern Rhymer or Dryden?
Latinizing missionaries who stretched native languages on the rack were able to give them Bibles in their own languages. Linguists produce accurate descriptive grammars which make beautiful epitaphs to those languages. Bahasa Indonesia has preserved Indonesian language at the cost of Indonesian languages; the French created France out of the possessions of the Capets by suppressing regional dialects; the Arabic world is a world only by its devotion to the language of the Koran.
All rules seem arbitrary until they are gone without; all systems of rules suffer rot, once useful provisions becoming shibboleths; but a language without rules is a house on fire. Fire is a kind of life, breathing and eating; but it is too much life, and it leaves only ashes. A language is not alive, something growing and maturing, until it has been settled prescriptively, not by itself but by learning from the grammarians of, and translators from, older languages. Thus, all literate languages are artificial languages; their changes belong to history, not culture. The natural development of English which descriptive grammarians would defend no longer exists. The successions of fashion are unlike the forces determining national costume or native dress; just so, the changes of of a written language belong not to the order of cultural change, but to the order of revolutions and discoveries—of change in worldview, where prescription is the necessary condition of consensus.