It is manifest that there cannot be two supreme powers in the same community, if both are to operate upon the same objects. But there is nothing in the nature of political sovereignty to prevent its powers from being distributed among different agents for different purposes. This is constantly seen under the same government, when its legislative, executive, and judicial powers are exercised through different officers; and in truth, when we come to the law-giving power alone, as soon as we separate its objects into different classes, it is obvious that there may be several enacting authorities, and yet each may be supreme over the particular subject committed to it by the fundamental arrangements of society. Supreme laws, emanating from separate authorities, may and do act on different objects without clashing, or they may act on different parts of the same object with perfect harmony. They are inconsistent when they are aimed at each other, or at the same indivisible object.[318] When this takes place, one or the other must yield; or, in other terms, one of them ceases to be supreme on the particular occasion. It was the purpose of the framers of the Constitution of the United States to provide a paramount rule, that would determine the occasions on which the authority of a State should cease to be supreme, leaving that of the United States unobstructed. Certain conditions were made necessary to the operation of this rule. The State law must conflict with some provision of the Constitution of the United States, or with a law of the United States enacted in pursuance of the constitutional authority of Congress, or with a treaty duly made by the authority of the Union. The operation of this rule constitutes the supremacy of the national government. It was supposed that, by a careful enumeration of the objects to which the national authority was to extend, there would be no uncertainty as to the occasions on which the rule was to apply; and as all other objects were to remain exclusively subject to the authority of the States within their respective territorial limits, the operation of the rule was carefully limited to those occasions.