Explanation: The King of the Samnites, after capturing a massive Roman army in a surprise attack, asked his father what he should do with so many soldiers. His father advised to kill them all. Being shocked at the harshness of the answer, he asked for another option. His father then replied that he should spare them all. Confused at the sudden change in direction, the King of the Samnites asked why the stark contrasts. His father replied: "By freeing the Romans you make friends of them; by killing them all, you deprive them of the ability to oppose you for a generation."
The King of the Samnites still did not like these answers, so he proposed a different plan to his father - that he would force the Romans to go under a yoke, as a sign of submission, killing only those who refused, so as to remind them who was the superior polity which must be obeyed. Then they would conclude a peace treaty on Samnite terms. His father, again, offered wisdom, saying that the Romans were too proud and too stubborn for such a thing to work - it would only enrage them in the end, and lead to more conflict.
The King of the Samnites forced the Roman army to pass under the yoke. When the Roman army returned to Rome, ashamed and defeated, the Senate declared that their surrender and acquescience to the peace treaty was unlawful, as it had not been approved by the Senate, and sent them right back out to fight the Samnites again.
This time, they won, and the King of the Samnites was eventually killed, and his kingdom subdued by the Roman Republic.
Moral of the story - listen to Machiavelli. "People should either be caressed or crushed. If you do them minor damage they will get their revenge; but if you cripple them there is nothing they can do. If you need to injure someone, do it in such a way that you do not have to fear their vengeance.โ