whose decisions there is no appeal. In this view of the question there can be no difficulty in admitting that the decisions of the supreme court are final and conclusive. Whatever comes within the legitimate cognizance of that tribunal, it has a right to decide, whether it be a question of the law, or of the Constitution; and no other tribunal can reverse its decision. The Constitution, which creates the supreme court, creates no other court of superior or appellate jurisdiction to it; and, consequently, its decisions are strictly "final." There is no power in the same government to which that court belongs, to reverse or control it, nor are there any means therein of resisting its authority. So far, therefore, as the Federal Constitution has provided for the subject at all, the supreme court is, beyond question, the final judge or arbiter; and this, too, whether the jurisdiction which it exercises be legitimate or usurped.
[ *81 ]*The terms "constitutional controversies" are still more indefinite. Every controversy which is submitted to the decision of a judicial tribunal, whether State or Federal, necessarily involves the constitutionality of the law under which it arises. If the law be not constitutional, the court cannot enforce it, and, of course, the question whether it be constitutional or not, necessarily arises in every case to which the court is asked to apply it. The very act of enforcing a law presupposes that its constitutionality has been determined. In this sense, every court, whether State or federal, is the "judge or arbiter of constitutional controversies," arising in causes before it; and if there be no appeal from its decision, it is the "final" judge or arbiter, in the sense already expressed.
Let us now enquire what "constitutional controversies" the federal courts have authority to decide, and how far its decisions are final and conclusive against all the world.
The third article of the Constitution provides that "The judicial powers shall extend to all cases in law and equity, arising under this Constitution, the laws of the United States, and the treaties made, or which shall be made, under their authority; to all cases affecting ambassadors, other public ministers and consuls; to all cases of admiralty and maritime jurisdiction; to controversies to which the United States shall be a party; to controversies between two or more States; between a State and
