The story concerns a farmer who finds a viper freezing in the snow. Taking pity on it, he picks it up and places it within his coat. The viper, revived by the warmth, bites his rescuer, who dies realizing that it is his own fault. The story is recorded in both Greek and Latin sources. In the former, the farmer dies reproaching himself “for pitying a scoundrel,” while in the version by Phaedrus the snake says that he bit his benefactor “to teach the lesson not to expect a reward from the wicked.” The latter sentiment is made the moral in Medieval versions of the fable. Odo of Cheriton‘s snake answers the farmer’s demand for an explanation with a counter-question, “Did you not know that there is enmity and natural antipathy between your kind and mine? Did you not know that a serpent in the bosom, a mouse in a bag and fire in a barn give their hosts an ill reward?”

Because it seems lessons for the populous are usually not learned by the populous.