A return to first principles in a republic is sometimes caused by the simple virtues of one man. His good example has such an influence that the good men strive to imitate him, and the wicked are ashamed to lead a life so contrary to his example.
Knowing how to fight made men more bold, because no one fears doing what it seems to him he has learned to do. Therefore, the ancients wanted their citizens to be trained in every warlike action.
It is necessary for him who lays out a state and arranges laws for it to presuppose that all men are evil and that they are always going to act according to the wickedness of their spirits whenever they have free scope.
The people resemble a wild beast, which, naturally fierce and accustomed to live in the woods, has been brought up, as it were, in a prison and in servitude, and having by accident got its liberty, not being accustomed to search for its food, and not knowing where to conceal itself, easily becomes the prey of the first who seeks to incarcerate it again.
Therefore, a prudent ruler ought not to keep faith when by so doing it would be against his interest, and when the reasons which made him bind himself no longer exist. If men were all good, this precept would not be a good one; but as they are bad, and would not observe their faith with you, so you are not bound to keep faith with them.