M. Tullius Cicero, De Officiis
Walter Miller, Ed.

[40] And again in the Second Punic War, after the¹ Battle of Cannae, Hannibal sent to Rome ten Roman captives bound by an oath to return to him, if they did not succeed in ransoming his prisoners; and as long as any one of them lived, the censors kept them all degraded and disfranchised, because they were [p. 45] guilty of perjury in not returning. And they punished in like manner the one who had incurred guilt by an evasion of his oath: with Hannibal's permission this man left the camp and returned a little later on the pretext that he had forgotten something or other; and then, when he left the camp the second time, he claimed that he was released from the obligation of his oath; and so he was, according to the letter of it, but not according to the spirit. In the matter of a promise one must always consider the meaning and not the mere words.

Our forefathers have given us another striking example of justice toward an enemy: when a deserter from Pyrrhus promised the Senate to administer poison to the king and thus work his death, the Senate and Gaius Fabricius delivered the deserter up to Pyrrhus. Thus they stamped with their disapproval the treacherous murder even of an enemy who was at once powerful, unprovoked, aggressive, and successful.