(A ruler) cannot and should not keep his word when to do so would go against his interests or when the reason he pledged it no longer holds.
Niccolo Machiavellithe wise man should always follow the roads that have been trodden by the great, and imitate those who have most excelled, so that if he cannot reach their perfection, he may at least acquire something of its savour.
Niccolo MachiavelliA prince... must learn from the fox and the lion... One must be a fox in order to recognize traps, and a lion to frighten off wolves. Those who act simply as lions are stupid. So it follows 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.
Niccolo MachiavelliMake mistakes of ambition and not mistakes of sloth. Develop the strength to do bold things, not to suffer.
Niccolo Machiavelli