A wise ruler ought never to keep faith when by doing so it would be against his interests. – Niccolo Machiavelli
War should be the only study of a prince. He should consider peace only as a breathing-time, which gives him leisure to contrive, and furnishes as ability to execute, military plans. – Niccolo Machiavelli
Men ought either to be indulged or utterly destroyed, for if you merely offend them they take vengeance, but if you injure them greatly they are unable to retaliate, so that the injury done to a man ought to be such that vengeance cannot be feared. – Niccolo Machiavelli
I consider it a mark of great prudence in a man to abstain from threats or any contemptuous expressions, for neither of these weaken the enemy, but threats make him more cautious, and the other excites his hatred, and a desire to revenge himself. – Niccolo Machiavelli