SUPREME COURT ON JUDICIAL LEGISLATION. 335 what it was is not controlling; for it may be assumed, even if the parties had knowledge of the decision, that they knew it was contrary to the cur- rent of authority in similar cases, and contracted, having in view the law as it actually existed. Like an unconstitutional law, void of itself, the decision was not the law, and is not to be regarded as authority for that reason." These observations have been thought proper by way of preface to the present discussion, to define its limits. It is not proposed to consider the cases of Swift v. Tyson, and Gelpcke v. Dubuque primarily as instances of judicial legislation, but because in the views taken of them by the court it was in each of them neces- sary to pronounce judicially upon the effect of final decisions in a foreign jurisdiction, and so upon the question of whether or not they were laws. This will appear more clearly after a brief state- ment of certain elementary propositions respecting the court's jurisdiction. With the exception of suits between citizens of the same State claiming land under grants from different States, the appellate jurisdiction of the Supreme Court is confined by the Constitution to two classes of suits. Cases may come up from both the inferior Federal courts and from the State courts of last resort because they involve questions arising under the Constitution, treaties, or laws of the United States ; and cases of all kinds may come up from the former courts, which have acquired jurisdiction solely by reason of the fact that the parties are citizens of different States. In these two classes of cases the Supreme Court exercises widely different functions. In cases involving Federal questions there can be no doubt whatever of the law to be applied by the court. It is the law of its own government ; that is, the law of the United States in the sphere of its sovereignty. The subject-matter of the suits falls under Federal cognizance only ; the questions involved arise under laws of the United States which are declared to be the supreme law of the land, and which are foreign and superior to the laws of the quasi-sovereignties of the States which compose the Union. That the laws of the United States should be ultimately construed by the courts of any other government is a proposition not to be seriously considered.^ In the second class of cases, on the 1 " If there are such things as political axioms, the propriety of the judicial power of a go%'ernment being coextensive with its legislative may be ranked among the num- ber." Hamilton, The Federalist, No, LXXX. 45
