John Stuart Mill
"The greatest orator, save one, of antiquity, has left it on record that he always studied his adversary's case with as great, if not still greater, intensity than even his own. What Cicero practiced as the means of forensic success requires to be imitated by all who study any subject in order to arrive at the truth. He who knows only his own side of the case knows little of that. His reasons may be good, and no one may have been able to refute them. But if he is equally unable to refute the reasons on the opposite side, if he does not so much as know what they are, he has no ground for preferring either opinion. The rational position for him would be a suspension of judgment." ~ John Stuart
