"It seems to me," said Sancho, "that the knights who did these things were provoked and had a reason to do senseless things and penances; but what reason does your grace have for going crazy? What lady has scorned you, and what signs have you found to tell you that my lady Dulcinea of Toboso has done anything foolish with Moor or Christian?"
"Therein lies the virtue," responded Don Quixote, "and the excellence of my enterprise, for a knight errant deserves neither glory nor thanks if he goes mad for a reason. The great achievement is to lose one's reason for no reason, and to let my lady know that if I can do this without cause, what should I not do if there were cause?"
Cervantes, Don Quixote. Trans. Edith Grossman.