That language is an instrument of human reason, and not merely a medium for the expression of thought, is a truth generally admitted.
    — George Boole, quoted in Iverson's Turing Award Lecture

Language is like a cracked kettle on which we beat our tunes to dance to, while all the time we long to move the stars to pity.
    — Flaubert

Do not put statements in the negative form.
And don't start sentences with a conjunction.
If you reread your work, you will find on rereading that a great deal of repetition can be avoided by rereading and editing.
Never use a long word when a diminutive one will do.
Unqualified superlatives are the worst of all.
If any word is improper at the end of a sentence, a linking verb is.
Avoid trendy locutions that sound flaky.
Never, ever use repetitive redundancies.
Also, avoid awkward or affected alliteration.
Last, but not least, avoid cliche's like the plague.
    — William Safire's rules for writing, quoted here

Short words are best and the old words when short are best of all.
    — Winston Churchill

A man, a plan, a canoe, pasta, heros, rajahs, a coloratura, maps, snipe, percale, macaroni, a gag, a banana bag, a tan, a tag, a banana bag again (or a camel), a crepe, pins, Spam, a rut, a Rolo, cash, a jar, sore hats, a peon, a canal-- Panama!
    — Guy Steele, CLTL2

What part of "turing complete" don't you understand?
    — The Cube, quoted by Edward O'Connor

I've just come back from the Conservative Party of New York dinner in midtown Manhattan and would like to make a couple of language notes. The magnificent Lynn Cheney was there, introducing her husband. She began her remarks with, "This is a great honor for Dick and me" and my heart leapt, that Mrs. Cheney should know how to use "me" and "I" correctly. I wanted to run and hug her (though the Secret Service would have made mincemeat of me). And a woman at my table made a bad face and said, "'Dick and me'? She's not even literate!" Ah, that's my country.
    — Jay Nordlinger

And this reminds me of an anecdote from the language maven, William Safire. Someone he hadn't seen in a long while said, "I've missed not seeing you." Safire corrected: "Well, actually, you've missed seeing me." The friend answered: "Maybe I was right the first time."
    — Jay Nordlinger