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

In these pages the novelist should be able to find a striking verse to head his chapter, the raconteur add to his bon mots, the man of the world enrich his stock of maxims, the divine obtain some deep thought drawn from the wells of ancient learning. – William Francis Henry King, “Introduction,” Classical and Foreign Quotations, 18

A single gnomic line can come to resonate with centuries of subsequent wisdom. – Gary Saul Morson, The Words of Others: From Quotations to Culture, 2011