M. Tullius Cicero Pro P. Sulla 63

[63] And Sulla is accused by Lucius Caecilius, in that business in which both of them deserve praise. In the first place Caecilius, for having proposed a law in which he appeared to wish to rescind an unjust decision; and Sulla, who reproved him, and chose to abide by the decision. For the constitution of the republic derives its principal consistency from formal legal decisions. Nor do I think that any one ought to yield so much to his love for his brother as to think only of the welfare of his own relations, and to neglect the common safety of all. He did not touch the decision already given, but he took away the punishment for bribery which had been lately established by recent laws. And, therefore, by this motion he was seeking, not to rescind a decision, but to correct a defect in the law. When a man is complaining of a penalty, it is not the decision with which he is finding fault but the law. For the conviction is the act of judges, and that is let stand; the penalty is the act of the law, and that may be lightened.