Next to the originator of a good sentence is the first quoter of it. Many will read the book before one thinks of quoting a passage. As soon as he has done this, that line will be quoted east and west. – Ralph Waldo Emerson, “Quotation and Originality,” Letters and Social Aims, 1876

Gnomic wisdom, however, is notoriously polychrome, and proverbs depend for their truth entirely on the occasion they are applied to. Almost every wise saying has an opposite one, no less wise, to balance it… – George Santayana, “Chapter VIII: Prerational Morality,” The Life of Reason: Volu

Books of quotation are not only of importance to the reader for what they contain of matured thought, but also for what they suggest. Our brains receive the spark and become luminous, like inflammable material by the contact of flint and steel. – Maturin M. Ballou, January 1886, preface to Edge-Tools of Speech