In this case we undoubtedly have the acceptance as law, by our courts, of an international usage, and that, too, one in whose favor neither universal and long-continued acceptance by nations nor unanimous advocacy by scientific commentators could be successfully urged. But this was by no means a repudiation of the principle declared by the Supreme Court in The Lottawanna case. The federal Constitution provides that Congress shall have the power to define and punish offenses against the law of nations, and to make rules concerning captures on land and water. Furthermore, it is declared that treaties made under the authority of the United States shall be the supreme law of the land. The effect of these clauses which recognize the existence of a body of international laws and the granting to Congress of the power to punish offenses against them, the courts have repeatedly held is to adopt these laws into our municipal law en bloc except where Congress or the treaty-making power has expressly changed them. Where, then, Congress has not acted, the courts properly hold that it is its intention that the generally recognized principles of international conduct shall be applied, in exactly the same way in which it has been held that with reference to the regulation of interstate commerce the silence of Congress is deemed equivalent to an expression of its will that that commerce shall be free

from control.

There was, therefore, in this Paquete Habana case that acceptance by the State which the courts have consistently declared is required for the transmutation of an international rule into a municipal command.

Where principles of international law are applicable they do not need to be proved as in the case of foreign municipal laws, but may be taken judicial cognizance of by the courts. That fishing smacks from capture in time of war is a practice generally sanctioned by modern practice and by the opinions of international law writers, as that it lies within the discretion of the executive power to determine the rigors of war, and that in the proclamation and directions which, in the exercise of that discretion, had been 'issued, no such exemption had been expressly or impliedly authorized.

is, they may, if not already known to the court, be ascertained by the court by its own study of the proper sources of information.9

§ 589. Federal Criminal Law.

There is no common, non-statutory, federal criminal law. The federal courts have no criminal jurisdiction save that given them by statute of Congress; and no act is recognized as a crime against the peace of the United States except such as has been declared such by act of Congress; and Congress has of course no constitutional power to define as a crime and affix a penalty to the commission thereof, except as to subjects or in places which the Constitution places under federal control, or as a means of compelling obedience to the laws which Congress is constitutionally empowered to enact.

But though the federal courts have no common-law federal jurisdiction, and though there is no common, non-statutory criminal law for them to administer, they may, and indeed have been authorized by statute to adopt common-law remedies and punishments where Congress has not otherwise provided. Thus section 722 of the Revised Statutes reads:

"The jurisdiction in civil and criminal matters conferred on the district and circuit courts by the provisions of this Title and of Title "Civil Rights" and of the Title "Crimes," for the protection of all persons in the United States in their civil rights and for their vindication, shall be exercised and enforced in conformity with the laws of the United States, so far as such laws are suitable to carry the same into effect; but in all cases where they are not adapted to the object, or are deficient in the provisions necessary to furnish suitable remedies and punish offenses against law, the common law, as modified and changed by the Constitution and statutes of the State wherein the court having jurisdiction of such civil or criminal cause is held, so far as the same is not inconsistent with the Constitution and law of the United States, shall be extended to govern the said courts in the 9 The Sectia, 14 Wall. 170; 20 L. ed. 822.

trial and disposition of the cause, and, if it is of a criminal nature, in the infliction of punishment on the party found guilty."

In Tennessee v. Davis,10 a case removed from the state into the federal court under section 643 of the Revised Statutes, it was argued that no mode of procedure in trial of the criminal offense charged had been prescribed by act of Congress. The court, however, said: "While it is true there is neither in section 643 nor in the act of which it is a re-enactment, any mode of procedure in the trial of a removed case prescribed, except that it is ordered, the cause when removed shall proceed as a cause originally commenced in that court, yet the mode of trial is sufficiently obvious. The circuit courts of the United States have all the appliances which are needed for the trial of any criminal case. They adopt and apply the laws of the State in civil cases, and there is no more difficulty in administering the State's criminal law. They are not foreign courts. The Constitution has made them courts within the States to administer the laws of the States in certain cases; and so long as they keep within the jurisdiction assigned to them, their general powers are adequate to the trial of any case."

§ 590. Federal Courts and the Construction of State Laws.

By the Constitution the federal courts are given jurisdiction. of all suits between two or more States, between a State and citizens of another State, between citizens of different States, between citizens of the same State claiming lands under grants of different States, and between a State, or the citizens thereof, and foreign States, citizens or subjects.

In this grant of jurisdiction the determining factor is not the nature of the matter litigated or the law involved, but the character of the parties to the suits. No question of federal concern, and no construction of a federal law or constitutional provision may be involved. The subjects to be determined may, and, indeed, usually, in this class of cases, depend wholly upon the

10 100 U. S. 257; 25 L. ed. 648.

interpretation and application of the laws of one or more of the States. The object in giving this jurisdiction to the federal courts is thus not the protection of federal rights, privileges, and immunities, but the provision of tribunals presumably more impartial than would be state tribunals when called upon to adjudicate between citizens of the State in which they are sitting and citizens of other States. This purpose is stated by Hamilton in No. LXXX of The Federalist. With reference to the clause of the Constitution providing that "the citizens of each State shall be entitled to all the privileges and immunities of citizens of the several States," he writes: "And if it be a just principle, that every government ought to possess the means of executing 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 State or its citizens are opposed to another State or its citizens. To secure the full effect of so fundamental a provision against all evasion and subterfuge, it is necessary that its construction should be committed to that tribunal, which, having no local attachments, will be likely to be impartial, between the different States and their citizens, and which, owing its official existence to the Union, will never be likely to feel any bias inauspicious to the principles on which it is founded."

That this exposition of Hamilton's correctly exhibits the aim sought by this provision is also shown by the debates in the Constitutional and State ratifying Conventions."1

In short, the theory is that the federal courts when thus called upon by reason of the diversity of the citizenship of the parties to construe and apply state law, are to consider themselves as ad hoc agents of the State, and, therefore, under an obligation to apply that law as they find it. This obligation was recognized in the 34th section of the original Judiciary Act of 1789, now section 721 of the Revised Statutes, which provides that: "The laws of the several States, except where the Constitution, 11 See, for example, Elliot's Debates, III, 533, 557, 566.

treaties, or statutes of the United States shall otherwise require or provide, shall be regarded as rules of decision in trials at common law, in the courts of the United States, in cases where they apply." This provision has remained unaltered to the present day, and constitutes section 721 of the Revised Statutes.

§ 591. Force of State Interpretations.

What the proper construction of the state law is, which they are to apply, the Supreme Court of the United States has repeatedly declared is, subject to the exceptions hereinafter to be described, to be determined by the interpretation that has been given to it by the State that has enacted it. In Elmendorf v. Tyler12 Marshall says: "The judicial department of every government, where such department exists, is the appropriate organ for construing the legislative acts of that government.

On this principle the construction given by this court to the Constitution and laws of the United States is received by all as the true construction; and on the same principle the construction given by the courts of the several States to the legislative acts of those States is received as true, unless they come in conflict with the Constitution, laws, and treaties of the United States." Again, in Shelby County v. Guy,13 the Supreme Court declare: "Nor is it questionable that a fixed and received construction of their respective statute laws in their own courts makes, in fact, a part of the statute law of the country, however we may doubt the propriety of that construction. It is obvious that this admission may at times involve us in seeming inconsistencies, as when States have adopted the same statutes and their courts differ in their construction. Yet that course is necessarily indicated by the duty laid on us to administer, as between certain individuals, the laws of their respective States according to the best lights we possess of what those laws are."

12 10 Wh. 152; 6 L. ed. 289. 13 11 Wh. 361; 6 L. ed. 495.