Keep Silent As Much As Possible
Be for the most part silent, or speak merely what is necessary, and in few words. - Epictetus
"Wise men speak because they have something to say. Fools because they have to say something." - Plato
The more you say, the more likely you are to say something foolish or revealing. Keeping your words measured and controlled gives you more power and keeps others guessing about your intentions and capabilities.
Related
Especially follow this when it when it comes to criticism see: HWFIP: Dont Condemn Criticize or Complain
The more you say, the more likely you are to say something foolish.
For different reason by same outcome
Keep silent as much as possible, saying only what you must say, and that briefly. Join a conversation when the occasion requires it, but not on the common subjects of sports, entertainment or dining; and especially not about persons, allotting them blame or praise or comparing them. If you can bring such a conversation around to better topics, fine, but if you’re among strangers, keep quiet. - Epictetus