Rule (n.) would be fought over in a city of good men in order not to hold it, as men now fight to rule.
Rule (n.) is taken up by decent people only out of fear of the worst penalty: being ruled by someone worse.
Rule (n.) is something no one willingly chooses, since it means taking other people's troubles in hand, so a person must be paid in money, honor, or a penalty for refusing.
Rule (n.) exists not to harm the ruled, as Thrasymachus thought, but because everyone is better off ruled by divine reason — best one's own, otherwise imposed from outside.
A Rule (n.) of conduct is either exceptionless but too vague ('be courageous') or precise but no guide to virtue ('never retreat in battle') — courage sometimes requires retreat.