M. Tullius Cicero Pro A. Cluentio 10

[10]
  The first point is this, from which it may be clearly seen that Cluentius had the greatest reason to confide in the justice of his cause, because he came down to accuse Albius relying on the most certain facts and unimpeachable witnesses. While on this topic, it is necessary for me, O judges, briefly to explain the accusations of which Albius was convicted. I demand of you, O Oppianicus, to believe that I speak unwillingly of the affair in which your father was implicated, because I am compelled by considerations of good faith, and of my duty as counsel for the defence. And, if I am unable at the present moment to satisfy you of this, yet I shall have many other opportunities of satisfying you at some future time; but unless I do justice to Cluentius now, I shall have no subsequent opportunity of doing justice to him. At the same time who is there who can possibly hesitate to speak against a man who has been condemned and is dead, on behalf of one unconvicted and living, when in the case of him who is being so spoken against conviction has taken away all danger of further disgrace, and death all fear of any further pain? and when, on the other hand, no disaster can happen to that man on behalf of whom one is speaking, without causing him the most acute feeling and pain of mind, and without branding his future life with the greatest disgrace and ignominy?