If a man says that it is right to give every one his due, and therefore thinks within his own mind that injury is due from a just man to his enemies but kindness to his friends, he was not wise who said so, for he spoke not the truth, for in no case has it appeared to be just to injure any one.
PlatoAgain, truth should be highly valued; if, as we were saying, a lie is useless to the gods, and useful only as a medicine to men, then the use of such medicines should be restricted to physicians; private individuals have no business with them.
Plato