A learned historian declared to me of a contemporary, that the latter had appropriated his researches; he might, indeed, and he had a right to refer to the same originals; but if his predecessor had opened the sources for him, gratitude is not a silent virtue. – Isaac D’Israeli, “Quotation,” A Second Series of Curiosities of Literature

Most of the classical citations you shall hear or read in the current journals or speeches were not drawn from the originals, but from previous quotations in English books… – Ralph Waldo Emerson, “Quotation and Originality,” Letters and Social Aims, 1876

A vast meaning is unfolded in each line, with such power that a sentence only a line long would suffice for a whole life’s training. – Rufinus (translated from Latin), about The Sentences of Sextus