Upon this, one has to remark that men ought either to be well treated or crushed, because they can avenge themselves of lighter injuries, of more serious ones they cannot; therefore the injury that is to be done to a man ought to be of such a kind that one does not stand in fear of revenge.
Ch. 3; Variant translation: Never do any enemy a small injury for they are like a snake which is half beaten and it will strike back the first chance it gets. - The Prince (1513)