“Indeed, there is no other way of guarding oneself from flattery than by letting men understand that they will not offend you by telling the truth.”Niccolò Machiavelli · Principele · 1532 · Capitolul XXIII
To rid yourself of flatterers, you must demonstrate that the truth does not anger you.
Machiavelli identifies flattery as a major danger for a leader: flatterers say what he wants to hear, not what he needs to know. To get rid of them, a prince must create a climate where people are not afraid to tell the truth. If a counselor knows he will be punished for bad news, he will lie. For example, a CEO who punishes constructive criticism will be surrounded by yes-men and will make wrong decisions.
Why it matters In any organization or relationship, encouraging honesty is the only antidote to interested lies; those who surround themselves with flatterers deceive themselves.