Besides what has been said, people are fickle by nature; and it is a simple to convince them of something but difficult to hold them in that conviction; and, therefore, affairs should be managed in such a way that when they no longer believe, they can be made to believe by force.
Niccolo Machiavelli(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 MachiavelliTherefore it is unnecessary for a prince to have all the good qualities I have enumerated, but it is very necessary to appear to have them.
Niccolo Machiavelli