But it is asserted that it was decided in the income tax cases that, in order to determine whether a tax be direct within the meaning of the Constitution, it must be ascertained whether the one upon whom by law the burden of paying it is first cast can thereafter shift it to another person. If he cannot, the tax would then be direct in the constitutional sense, and, hence, however obvious in other respects it might be a duty, impost, or excise, it cannot be levied by the rule of uniformity, and must be apportioned. From this assumed premise it is argued that death duties cannot be shifted from the one on whom they are first cast by law, and therefore they are direct taxes requiring apportionment.
The fallacy is in the premise. It is true that in the income tax cases the theory of certain economists by which direct and indirect taxes are classified with reference to the ability to shift the same was adverted to. But this disputable theory was not the basis of the conclusion of the court. The constitutional meaning of the word direct was the matter decided. Considering that the constitutional rule of apportionment had its origin in the purpose to prevent taxes on persons solely because of their general ownership of property from being levied by any other rule than that of apportionment, two things were decided by the court: First, that no sound distinction existed between a tax levied on a person solely because of his general ownership of real property, and the same tax imposed solely because of his general ownership of personal property. Secondly, that the tax on the income derived from such property, real or personal, was the legal equivalent of a direct tax on the property from which said income was derived, and hence must be apportioned. These conclusions, however, lend no support to the contention that it was decided that duties, imposts and excises which are not the essential equivalent of a tax on property generally, real or personal, solely because of its ownership, must be converted into direct taxes, because it is conceived that it would be demonstrated by a close analysis that they could not be shifted from the person upon whom they first fall. The proposition now relied upon was considered and refuted in Nicol v. Ames, 173 U.S. 509 , 43 L. ed. 786, 19 Sup. Ct. Rep. 522, where the court said
( p. 515, L. ed. p. 791, Sup. Ct. Rep. p. 525):
'The commands of the Constitution in this, as in all other respects, must be obeyed; direct taxes must be apportioned, while indirect taxes must be uniform throughout the United States. But while yielding implicit obedience to these constitutional requirements, it is no part of the duty of this court to lessen, impede, or obstruct the exercise of the taxing power by merely abstruse and subtle distinctions as to the particular nature of a specified tax, where such distinction rests more upon the differing theories of political economists than upon the practical nature of the tax itself.
'In deciding upon the validity of a tax with reference to these requirements, no microscopic examination as to the purely economical or theoretical nature of the tax should be indulged in for the purpose of placing it in a category which would invalidate the tax. 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. 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.'