Page:Joseph Story, Commentaries on the Constitution of the United States (1st ed, 1833, vol I).djvu/485

 CH. VI.] § 462. And, here, we must guard ourselves against an error, which is too often allowed to creep into the discussions upon this subject. The preamble never can be resorted to, to enlarge the powers confided to the general government, or any of its departments. It cannot confer any power per se; it can never amount, by implication, to an enlargement of any power expressly given. It can never be the legitimate source of any implied power, when otherwise withdrawn from the constitution. Its true office is to expound the nature, and extent, and application of the powers actually conferred by the constitution, and not substantively to create them. For example, the preamble declares one object to be, "to provide for the common defence." No one can doubt, that this does not enlarge the powers of congress to pass any measures, which they may deem useful for the common defence. But suppose the terms of a given power admit of two constructions, the one more restrictive, the other more liberal, and each of them is consistent with the words, but is, and ought to be, governed by the intent of the power; if one would promote, and the other defeat the common defence, ought not the former, upon the soundest principles of interpretation to be adopted? Are we at liberty, upon any principles of reason, or common sense, to adopt a restrictive meaning, which will defeat an avowed object of the constitution, when another equally natural and more appropriate to the object is before us? Would not this be to destroy an instrument by a measure of its words, which that instrument itself repudiates?