We prefer to think that the absence of inverted commas guarantees the originality of a thought, whereas it may be merely that the utterer has forgotten its source. – Clifton Fadiman, The American Treasury, 1455-1955, 1955

A true quotation cannot be divorced from the character who uttered or scribbled it; it should say as much about the person quoted as about the particular subject referred to, and for this reason an anthology of quotations should be a kind of portrait gallery. – Robert Andrews, The Columbia Dictionary of Quotations, “Introduction”

Whenever we would prepare the mind by a forcible appeal, an opening quotation is a symphony preluding on the chords whose tones we are about to harmonize. – Isaac D’Israeli, “Quotation,” A Second Series of Curiosities of Literature