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

Dr. Richard Bentley (1662-1742)… is said one day, on finding his son reading a novel, to have remarked—’Why read a book that you cannot quote?’— a saying which affords an amusing illustration of the nature and object of his literary studies. – Cyclopædia of English Literature edited by Robert Chambers, 1844

When two seemingly conflicting thoughts have made it to proverb or aphorism status, usually, in the ambivalence of life, both are true. – Robert Irvine Fitzhenry (1918–2008), The Harper Book of Quotations