Since Don Quixote de la Mancha is a crazy fool and a madman, and since Sancho Panza, his squire, knows it, yet, for all that, serves and follows him, and hangs on these empty promises of his, there can be no doubt that he is more of a madman and a fool than his master.

Ch. 33 (translation by J. M. Cohen, 1950). - Don Quixote de la Mancha (1605–1615) - Part II (1615) - Book III