336 HARVARD LAW REVIEW. Other hand, the Federal jurisdiction is not exclusive, but con- current with that exercised by the courts of the States. The sub- jects of the suits are not matters of Federal control. The law to be administered is not United States, but State law, — the Federal courts, of course, act within their own jurisdiction in one sense; but that jurisdiction only calls for the administration of the law of another government, namely, the State where the controversy arose, or in reference to whose laws the parties have dealt, so that ultimately the law to be applied is the law of a foreign jurisdiction. It would seem that upon the question of what is the law of a given State the decision of the highest court of that State should be conclusive, whether we regard the decision as being itself the law or merely as evidence of the law, and that the sole duty of the Federal court in the exercise of this peculiar jurisdiction is to discover, if possible, from the precedents and analogies to be found in the decisions of the State courts, a rule covering the case before it, and then to apply that rule. The Federal judges should be as much bound by a State decision upon a question of State law, as a State court is bound by a Supreme Court decision upon a question of Federal law. Only thus can the purposes of the jurisdiction be fully an- swered. The best contemporary evidence accessible, read in the light of recognized principles of statutory construction, supports this proposition. Before the adoption of the Constitution, suits between citizens of dififerent States were tried in the State courts, there being no other. The evil felt and feared in this system was the effect of prejudice against suitors who were not citizens, and the remedy sought was the creation of an impartial tribunal to admin- ister the law of the State in which it sat.^ This was the under- standing of Hamilton, who, indeed, regarded this jurisdiction as auxiliary to the constitutional provision that the citizens of each State shall be entitled to all the privileges and immunities of the citizens of the several States. " If," he wrote, " it be a just prin- ciple that every government ought to possess the means of ex- ecuting its own provisions by its own authority, it will follow that in order to the inviolable maintenance of that equality of privileges and immunities to which the citizens of the Union will be entitled, the national judiciary ought to preside in all cases in which one 1 Elliott's Debates, Vol. III. pp. 533, 534, 549, 557, 566.
