A man who is used to acting in one way never changes; he must come to ruin when the times, in changing, no longer are in harmony with his ways.

Verträge bricht man um des Nutzens willen.

Keep your friends close, keep your enemies closer.

… to a Prince who wants to do great things, it is necessary to learn to deceive.

It is necessary for a prince wishing to hold his own to know how to do wrong, and to make use of it or not according to necessity.

It is of the greatest important in this world that a man should know himself, and the measure of his own strength and means; and he who knows that he has not a genius for fighting must learn how to govern by the arts of peace.