Not everything that can be extracted appears in anthologies of quotations, in commonplace books, or on the back of Celestial Seasonings boxes. Only certain sorts of extracts become quotations. – Gary Saul Morson, The Words of Others: From Quotations to Culture, 2011

I am wonderfully pleased when I meet with any passage in an old Greek or Latin author, that is not blown upon, and which I have never met with in any quotation. – Joseph Addison, Spectator, No.464

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