Someone — Cyril Connolly? Ezra Pound? — once said that anything that can be read twice is literature; I would say that anything that bears saying twice is quotable. – Joseph Epstein, “Quotatious,” A Line Out for a Walk: Familiar Essays, 1991
I am now to offer some thoughts upon that sameness or familiarity which we frequently find between passages in different authors without quotation. This may be one of three things either what is called Plagiarism, or Imitation, or Coincidence. – James Boswell, “The Hypochondriack,” No.XXII, 1779