Once upon a time there was a boy who had a bad habit of talking more than was necessary.
"What a tongue!" sighed the teeth one day. "It is never still, never quiet!"
"What are you grumbling about?" replied the tongue arrogantly. "You teeth are only slaves, and your job is merely to chew whatever I decide. We have nothing in common, and I shall not allow you to meddle in my affairs."
So the boy went on chattering, very impertinently sometimes, and his tongue was happy, learning new words every day.
But one day, when the boy did some damage, and then allowed his tongue to tell a big lie, the teeth obeyed the heart, sprang together and bit the tongue.
From that day onward the tongue became timid and prudent, and thought twice before speaking.
From Fables of Leonardo da Vinci