Here’s a little medieval Spanish story with a moral and a punch line. It comes from El Conde Lucanor (Count Lucanor), a book written in 1335 by Sir Juan Manuel (1282-1348), Prince of Villena and nephew of King Alfonso X the Wise of Castile.

The book is filled with “exemplary stories” to help the fictitious Count Lucanor deal with his concerns. In Example XLIII, the Count asks how much he should tolerate from bad people. His advisor Patronio tells him this cautionary story about putting up with bad behavior, whose final line became a medieval refrain (translation mine):

“A good man had a public bath, and one day a madman came to the bath when people were bathing. He hit them with buckets and stones and sticks and everything else he could find, so no one in the world dared to go to the bath that belonged to the good man. He lost his source of income.

“When the good man realized that the madman was making his business fail, he got up early one day and went to the bath before the madman came. He took off his clothes and got a bucket of boiling water and a large wooden club. Then the madman who had been attacking people arrived at the bath.

“The naked good man, who was waiting, saw him and ran toward him with courage and anger. He threw the bucket of boiling water at the madman’s head and grabbed the club and began to strike him again and again on his head and body. The madman was afraid he would be killed.

“He ran out screaming, and someone asked him why he was running and yelling. The madman told him:

“ ‘My friend, beware, there is another madman in the bath.’ ”