Therefore 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. And I shall dare to say this also, that to have them and always to observe them is injurious, and that to appear to have them is useful; to appear merciful, faithful, humane, religious, upright, and to be so, but with a mind so framed that should you require not to be so, you may be able and know how to change to the opposite.
Niccolo MachiavelliIt is a true observation of ancient writers, that as men are apt to be cast down by adversity, so they, are easily satiated with prosperity, and that joy and grief produce the same effects. For whenever men are not obliged by necessity to fight they fight from ambition, which is so powerful a passion in the human breast that however high we reach we are never satisfied.
Niccolo Machiavelli