The power of our Supreme Court is great, and its sphere is vast; but there are limits to its power and its sphere. According to the Constitution, "the judicial power shall extend to _all cases_ in law and equity, arising under the Constitution, the laws of the United States, and treaties"; but it by no means follows that the interpretation of the Constitution, _incident_ to the trial of these "cases," is final. Of course, the judgment in the "case" actually pending is final, as the settlement of a controversy, for weal or woe, to the litigating parties; but as a _precedent_ it is not final even on the Supreme Court itself. When cited afterwards, it will be regarded with respect as an _interpretation of the Constitution_, and, if nothing appears against it, of controlling authority; but, at any day, in any litigation, at the trial of any "case," it will be within the unquestionable competency of the Court to review its own decision, _so far as it establishes any interpretation of the Constitution_. If the Court itself be not constrained by its own precedents, how can coördinate branches, under oath to support the Constitution, and, like the Court itself, called _incidentally_ to interpret the Constitution, be constrained by them? In both instances, the power to interpret is simply _incident_ to other principal duties, as the trial of "cases," the making of laws, or the administration of government; and it seems as plainly _incident_ to a "case" of legislation or of administration as to a "case" of litigation. And on this view I shall act with entire confidence, under the oath I have taken.