Be cautious when trusting prudent men. They may minimize issues related to their own duties and be too generous when judging the reputations of others. They will not reveal if anyone has spoken badly about you in their presence, nor whom you should be wary of, or what vices they themselves struggle with. The same is true of priests when they praise their penitents, because they can say nothing but good about them, no less than parents about their children.

If you fear that someone may complain about you, cause trouble, or do something along those lines in your absence, keep them close to you. Engage them in activities under the guise of friendship, such as entertainments, hunting, dining, conversation, or military service. Thus, to prevent neighboring nations from rebelling while you are engaged in another war, bring their leaders with you, accompanied by a small, trusted force, as if they were your most loyal allies.

It will be useful to have a mirror in front of you while you sit at table or write, so that you may see what is being done behind your back.