HOW PRINCES SHOULD HONOUR THEIR WORD

Everyone realizes how praiseworthy it is for a price to honor his word and to be straightforward rather than crafty in his dealings; none the contemporary experience shows that princes who have achieved great things have those who have given their word lightly, who have known how to trick men with their cunning, and who, in the end, have overcome those abiding by honest principles.
You must understand, therefore, that there are two ways of fighting; by law or by force. The first way is natural to men, and the second to beasts. But as the first way often proves inadequate one must needs have recourse to second. So a prince must understand how to make a nice use of the beast and the man. The ancient writers taught princes about this by an allegory, when they described how Achilles and many other princes of the ancient word were sent to be brought up by Chiron, the centaur, so that he might train them his way. All the allegory means, in making the teacher half beast and half man, is that a prince must know how to act according to the nature of both, and that he cannot survive otherwise.
So, as a prince is forced to know how to act like a beast, he must learn from the fox and the lion; because the lion is defenseless against traps and a fox is defenseless against wolves. Therefore one must be a fox in order to recognize traps, and a lion to frighten off wolves. Those who simply act like lion are stupid. So it fellows that a prudent ruler cannot, and must not, honour his word when it places him at a disadvantage and when the reasons for which he made his promise no longer exist.