But in the reasoning of the court in support of this decision some expressions are used which go far beyond it.... The general expressions in the case of Marbury _v._ Madison must be understood with the limitations which are given to them in this opinion; limitations which in no degree affect the decision in that case or the tenor of its reasoning." He then proceeded to dispose of the case in hand by saying that Virginia having obtained an erroneous judgment against Cohens, Cohens had a right to appeal, and the suit still remained a suit by a State against him and not by him against a State. Unfortunately, here again came in next an _obiter dictum_. If, he said, this were not so, there was another principle equally decisive in support of the jurisdiction, namely, that the Constitution gave the United States judicial power over all cases arising under the Constitution or laws of the United States without respect to parties. Nearly a hundred years later a State was sued in the courts of the United States on a cause of action arising under the Constitution, and Cohens _v._ Virginia was relied on as a precedent. "It must be conceded," was the reply of the Supreme Court, "that the last observation of the Chief Justice does favor the argument of the plaintiff. But the observation was unnecessary to the decision, and in that sense extra-judicial, and though made by one who seldom used words without due reflection, ought not to outweigh the important considerations referred to which lead to a different conclusion."[Footnote: Hans _v._ Louisiana, 134 United States Reports, 1, 20.] It may be added that decisions on a point not material to the cause are generally made without the benefit of previous argument by counsel. The lawyers will naturally address themselves to the controlling questions, and if well trained will see what these are quite as clearly as the court. It is the argument at the bar, in which different views of law are presented and each defended by men of learning and ability, which enables the judge, after hearing both sides and weighing all that is said in behalf of one against all that is said in behalf of the other, to come to the true conclusion. The Romans recognized this in their rule as to the force of precedent in a matter of customary law. The first thing to ask was whether "_contradicto aliquando judicio consuetudo firmata sit_."[Footnote: "Digest," 1, 3, _de legibus_, etc., 34.]