Prudence is nothing more than the wisdom to make the right judgment regarding what to say or not to say, what to do or not to do, when, where, and how. Prudence is the prince of all virtues. Saint Thomas Aquinas (thirteenth century AD) said prudence was right reason in action.
Prudence not only tells us when it is appropriate to act or speak but to what degree, in what way, and with what limits. It also judges when it is best to wait, or to do or say nothing.
A prudent person does not speak when he or she is angry lest what they say be tempered by their emotion. Prudence will say it is better to talk to someone when both of you have cooled off and are more objective. Prudence also says that urgency and emergency may warrant drastic measures, like yelling at someone who is in imminent danger. There may not be time for polite discourse.
Arguing with a criminal who has a lethal weapon pointed at you or at others is not prudent. Calmly trying to negotiate a peaceful and nonviolent resolution could be prudent, depending on what was being negotiated. Using proportionate force is prudent, for example, wounding a criminal instead of killing him if he refuses to surrender.
Prudence also helps nations avoid war by working to resolve differences diplomatically or economically before resorting to physical force.