Any injury we do to a man must be such that we need not fear his vengeance. - Niccolò Machiavelli

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.

Minds are of three kinds: one is capable of thinking for itself; another is able to understand the thinking of others; and a third can neither think for itself nor understand the thinking of others. The first is of the highest excellence, the second is excellent, and the third is worthless.

There is no other way of guarding against adulation, than to make people understand that they will not offend you by speaking the truth. On the other hand, when everyone feels at liberty to tell you the truth, they will be apt to be lacking in respect to you.