Machiavelli — "The promise given was a necessity of the past: the word broken is a necessity of…"

"The vulgar crowd always is taken by appearances, and the world consists chiefly of the vulgar."

"He who desires to found a state and give it laws, must start with the assumption that all men are bad, and ever ready to display their vicious nature, whenever they may find occasion for it."

"The prince who relies entirely on fortune is ruined when she changes."

"There are three kinds of intellect: one which comprehends by itself; another that discerns what another comprehends; and a third which comprehends neither by itself nor by the showing of another."

"Men are by nature much more inclined to evil than to good; and therefore, if you would have the good, you must put them under the necessity of being so."