In nations which constitute a single body politic, when a question is debated between two courts relating to their mutual jurisdiction, a third tribunal is generally within reach to decide the difference; and this is effected without difficulty, because in these nations the questions of judicial competency have no connexion with the privileges of the national supremacy. But it was impossible to create an arbiter between a superior court of the Union and the superior court of a separate state, which would not belong to one of these two classes. It was therefore necessary to allow one of these courts to judge its own cause, and to take or to retain cognizance of the point which was contested. To grant this privilege to the different courts of the states, would have been to destroy the sovereignty of the Union _de facto_, after having established it _de jure_; for the interpretation of the constitution would soon have restored that portion of independence to the states of which the terms of that act deprived them. The object of the creation of a federal tribunal was to prevent the courts of the states from deciding questions affecting the national interests in their own department, and so to form a uniform body of jurisprudence for the interpretation of the laws of the Union. This end would not have been accomplished if the courts of the several states had been competent to decide upon cases in their separate capacities, from which they were obliged to abstain as federal tribunals. The supreme court of the United States was therefore invested with the right of determining all questions of jurisdiction.[145] This was a severe blow upon the independence of the states, which was thus restricted not only by the laws, but by the interpretation of them; by one limit which was known, and by another which was dubious; by a rule which was certain, and a rule which was arbitrary. It is true the constitution had laid down the precise limits of the federal supremacy, but whenever this supremacy is contested by one of the states, a federal tribunal decides the question. Nevertheless, the dangers with which the independence of the states was threatened by this mode of proceeding are less serious than they appear to be. We shall see hereafter that in America the real strength of the country is vested in the provincial far more than in the federal government. The federal judges are conscious of the relative weakness of the power in whose name they act, and they are more inclined to abandon a right of jurisdiction in cases where it is justly their own, than to assert a privilege to which they have no legal claim. * * * * * DIFFERENT CASES OF JURISDICTION.