Nihil est incertius vulgo, nihil obscurius voluntate hominum, nihil fallacius ratione tota comitiorum. (Nothing is more unpredictable than the mob, nothing more obscure than public opinion, nothing more deceptive than the whole political system.)
This is the part of a great man, after he has maturely weighed all circumstances, to punish the guilty, to spare the many, and in every state of fortune not to depart from an upright, virtuous conduct.