DE CIVILITATE MORVM On Civility in Manners

XXXIIII.
Is it considered urbane to bite the lips with the teeth? No: because that is the mark of one threatening, and of one who is angry and inwardly chafing.

XXXV.
Why is it indecorous to mock someone by sticking out the tongue? Because that is the way of buffoons, who, having no regard for modesty or dignity, perpetrate anything they wish, to such an extent that he who is once a buffoon can never be a good head of a household.

XXXVI.
What is fitting for boys to do when spitting? To turn the body away, so they do not soil or splash anyone. Then, if they have ejected anything thick onto the ground, to trample it with the foot, so they do not cause nausea in anyone; if that is not allowed, to catch the spittle in a small cloth.

XXXVII.
Why is it considered uncivil to spit at every third word, as some are accustomed to do? Because the custom is shameful, having originated from the workshops of certain cobblers, and the proverb Psecas aut ros A sprinkle or dew censures those who spit frequently, not out of necessity, but out of habit.