The argument, we think, in any aspect in which it may be viewed, is utterly destitute of support upon any principles of constitutional law, as, according to that, Congress has no power whatever over the subject of slavery within the State; and is also subversive of the established doctrine of international jurisprudence, as, according to that, it is an axiom that the laws of one Government have no force within the limits of another, or extra-territorially, except from the consent of the latter. It is perhaps not unfit to notice, in this connection, that many of the most eminent statesmen and jurists of the country entertain the opinion that this provision of the act of Congress, even within the territory to which it relates, was not authorized by any power under the Constitution. The doctrine here contended for, not only upholds its validity in the territory, but claims for it effect beyond and within the limits of a sovereign State--an effect, as insisted, that displaces the laws of the State, and substitutes its own provisions in their place. The consequences of any such construction are apparent. If Congress possesses the power, under the Constitution, to abolish slavery in a Territory, it must necessarily possess the like power to establish it. It cannot be a one-sided power, as may suit the convenience or particular views of the advocates. It is a power, if it exists at all, over the whole subject; and then, upon the process of reasoning which seeks to extend its influence beyond the Territory, and within the limits of a State, if Congress should establish, instead of abolish, slavery, we do not see but that, if a slave should be removed from the Territory into a free State, his status would accompany him, and continue, notwithstanding its laws against slavery. The laws of the free State, according to the argument, would be displaced, and the act of Congress, in its effect, be substituted in their place. We do not see how this conclusion could be avoided, if the construction against which we are contending should prevail. We are satisfied, however, it is unsound, and that the true answer to it is, that even conceding, for the purposes of the argument, that this provision of the act of Congress is valid within the Territory for which it was enacted, it can have no operation or effect beyond its limits, or within the jurisdiction of a State. It can neither displace its laws, nor change the status or condition of its inhabitants. Our conclusion, therefore, is, upon this branch of the case, that the question involved is one depending solely upon the law of Missouri, and that the Federal court sitting in the State, and trying the case before us, was bound to follow it.