JOSEPHUS mentions that Tiberius Cæsar, inquiring why the governors of provinces remain so long in office, was answered by an example. "I have seen," said the respondent, "an infirm man covered with ulcers, grievously tormented by a swarm of flies. When asked why he did not use a flap and drive off his tormentors, he answered, 'The very circumstance which you think would relieve me would, in effect, cause tenfold suffering. For by driving away the flies now saturated with my blood, I should afford an opportunity to those that were empty and hungry to supply their place. And who doubts that the biting of a hungry insect is ten thousand times more painful than that of one completely gorged, unless the person attacked be stone, and not flesh.'"
