Summary

Edward Douglass White Knowlton v. Moore — Opinion of the Court

Taxation is eminently practical, and is, in fact, brought to every man's door, and for the purpose of deciding upon its validity a tax should be regarded in its actual, practical results, rather than with reference to those theoretical or abstract ideas whose correctness is the subject of dispute and contradiction among those who are experts in the science of political economy.'
Concluding, then that the tax under consideration is not direct within the meaning of the Constitution, but, on the contrary, is a duty or excise, we are brought to consider the question of uniformity.
Source: Wikisource

Edward Douglass White Knowlton v. Moore — Opinion of the Court

As a mere abstract, scientific, or economical problem, a particular tax might possibly be regarded as a direct tax, when as a practical matter pertaining to the actual operation of the tax it might quite plainly appear to be indirect. Under such circumstances, and while varying and disputable theories might be indulged as to the real nature of the tax, a court would not be justified, for the purpose of invalidating the tax, in placing it in a class different from that to which its practical results would consign it.
Source: Wikisource

Edward Douglass White Knowlton v. Moore — Opinion of the Court

Even the then members of the Congress who had not been delegates to the convention which framed the Constitution must have had a keen appreciation of the influences which had shaped the Constitution and the restrictions which it embodied, since all questions which related to the Constitution and its adoption must have been, at that early date, vividly impressed on their minds. It would, under these conditions, be indeed surprising if a tax should have been levied without question upon objects deemed to be beyond the grasp of Congress because exclusively within state authority.
Source: Wikisource

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