Marshall premised his conclusion on two lines of reasoning, the first structural and the second textual. The structural argument described the Constitution as a foundational charter that created a system of government designed to address problems of national concern. The specific grants of power marked the outlines of that government’s authority, but could not describe the details or the future contingencies to which the granted powers might be applied. Moreover, Marshall assumed that the people would want this national government to be an effective government. He reasoned, therefore, that the Constitution vested Congress with the authority to select reasonable means through which to exercise its constitutional responsibilities. Thus, after outlining several granted powers that implicated monetary concerns—“the great powers to lay and collect taxes; to borrow money; to regulate commerce; to declare and conduct a war; and to raise and support armies and navies,” 17 U.S. at 407—Marshall observed,
But it may with great reason be contended, that a government, entrusted with such ample powers, on the due execution of which the happiness and prosperity of the nation so vitally depends, must also be entrusted with ample means for their execution. The power being given, it is the interest of the nation to facilitate its execution. It can never be their interest, and cannot be presumed to have been their intention, to clog and embarrass its execution by withholding the most appropriate means.
17 U.S. at 408. He then explained, somewhat elliptically, why the creation of a national bank was a reasonable means to effectuate the previously described granted powers:
Throughout this vast republic, from the St. Croix to the Gulph of Mexico, from the Atlantic to the Pacific, revenue is to be collected and expended, armies are to be marched and supported. The exigencies of the nation may require that the treasure raised in the north should be transported to the south, that raised in the east conveyed to the west, or that this order should be reversed. Is that construction of the constitution to be preferred which would render these operations difficult, hazardous, and expensive? Can we adopt that construction, (unless the words imperiously require it,) which would impute to the framers of that instrument, when granting these powers for the public good, the intention of impeding their exercise by withholding a choice of means?
Id. at 408. Marshall’s answer to his rhetorical questions was an emphatic no.
The second component of Marshall’s argument focused directly on the Necessary and Proper Clause. “But the constitution of the United States has not left the right of Congress to employ the necessary means, for the execution of the powers conferred on the government, to general reasoning.” Id. at 411. The Necessary and Proper Clause was, according to Marshall, a textual affirmation of that general reasoning. In so concluding, he rejected the state’s argument that the Necessary and Proper Clause was designed to limit Congress to the choice of those means that were the “most direct and simple.” Id. at 413. Necessary did not mean absolutely necessary. “To employ the means necessary to an end, is generally understood as employing any means calculated to produce the end, and not as being confined to those single means, without which the end would be entirely unattainable.” Id. at 413-414. He further explained, in terms that echoed his general reasoning: