The Relative Pronouns "That" and "Which"

Before I begin, I'd like to remind my opponent that the word "however" is not a coordinating conjunction in the English language (http://www.chompchomp.com...). I've seen him make this mistake not only in this debate but in many of his others as well, and I would like to remind him that the only coordinating conjunctions that exist in the English language are "for," "and," "nor," "but," "or," "yet," and "so." I've listed them in their present order to form the mnemonic "FANBOYS," which I suspect will be easier to remember. Also curious is how my American opponent chooses to place the comma after the end quotation mark when the two marks are placed together. I say "curious," because such style is indicative of British writers, not American. But I should really stop myself. After all, such style choices do not matter. In fact, they don't even affect the readability of my opponent's opening argument. His style choices are his style choices, and there is no intrinsic reason for me to nitpick. For that matter, how did such "rules"--which my opponent has broken on multiple accounts in his opening argument--ever come to be in the first place? As it turns out, the which/that distinction first came into being with Henry W. Fowler's "A Dictionary of Modern English Usage." Luckily for my opponent and me and the audience, the original, historic book was republished in 2009, so we can find it at any major library. In this book, we can find Fowler's original proposal to distinguish between "that" and "which." Quickly after making this proposal, though, Fowler concedes that it is "not the practice of most or of the best writers." In addition, Fowler argues against ending sentences with prepositions and using split infinitives, suggestions which both my opponent and I know are archaic. (See: http://books.google.com..., on page 635) Simply put, Fowler's "rules" are outdated. Even such conservative grammarians as E. B. White, author of the monumental "The Elements of Style," has written such lines as, "the premature expiration of a pig is, I soon discovered, a departure which the community marks solemnly on its calendar." (See: http://books.google.com...) The that/which distinction was poorly invented by a man who also invented so called "rules" that virtually no one follows today. There is no distinction between restrictive and nonrestrictive clauses, just as it is not incorrect to end a sentence with a preposition or to split an infinitive. My opponent called my examples "anecdotal" and "incorrect"--my opponent also seems to have ignored my quote from the "American Heritage Book of English Usage"--but he fails to realize that the majority simply do no follow such archaic rules. This is the definition of "which" provided by the Webster's New World College Dictionary: "that: used as a relative referring to the thing, group, or event specified in the antecedent word, phrase, or clause: which can be used in a restrictive clause, in a restrictive clause preceded by the pronoun that, in a nonrestrictive clause, or, archaically, of a person." These are two definitions of "which" provided by "The American Heritage Dictionary of the English Language": "Used as a relative pronoun in a clause that provides additional information about the antecedent" and "Used instead of that as a relative pronoun in a clause that defines or restricts the antecedent." This is from the definition provided by "Cambridge Advanced Learner's Dictionary": "used as the subject or object of a verb to show what thing or things you are referring to, or to add information about the thing just mentioned." I could go on and on... No, my examples are not anecdotal. They are consensus. So, to sum up, the relative pronouns "that" and "which" are entirely interchangeable because (1) there is no intrinsic benefit in having such a distinction, (2) many professional writers and journalists make no such distinction, (3) most professional style guides and dictionaries make no such distinction, and (4) there has never been any historical precedent for such a distinction and such a distinction was indeed proposed by too conservative a grammarian who admits himself that there is no historical precedent. The distinction between "that" and "which" is similar to ending sentences with prepositions and splitting infinitives: all these "rules" are merely those that have been perpetuated by pretentious and chauvinistic grammarians who know nothing of the current English landscape.