Any harm you do to a man should be done in such a way that you need not fear his revenge.
Niccolo MachiavelliFor a prince should have two fears: one, internal concerning his subjects; the other, external, concerning foreign powers. From the latter he can always defend himself by his good troops and friends; and he will always have good friends if he has good troops.
Niccolo MachiavelliA prince, therefore, must not mind incurring the charge of cruelty for the purpose of keeping his subjects united and confident; for, with a very few examples, he will be more merciful than those who, from excess of tenderness, allow disorders to arise, from whence spring murders and rapine; for these as a rule injure the whole community, while the executions carried out by the prince injure only one individual. And of all princes, it is impossible for a new prince to escape the name of cruel, new states being always full of dangers.
Niccolo Machiavelli