10 But in the case of man, hard as it is for him to learn how to submit to rule, it seems far harder to know how to rule over men, and hardest of all, with this rule of ours, which leads them by the divine law, and to God, for its risk is, in the eyes of a thoughtful man, proportionate to its height and dignity. For, first of all, he must, like silver or gold, though in general circulation in all kinds of seasons and affairs, never ring false or alloyed, or give token of any inferior matter, needing further refinement in the fire; or else, the wider his rule, the greater evil he will be. Since the injury which extends to many is greater than that which is confined to a single individual.
Source: Orations (New Advent)