Page:Joseph Story, Commentaries on the Constitution of the United States (1st ed, 1833, vol II).djvu/429

 CH. XIV.] the words of the constitution without supposing them to exist,) it would seem, that congress is left at full liberty to levy the same by either rule, or by a mixture of both rules, or perhaps by any other rule, not inconsistent with the general purposes of the constitution. It is evident, that "duties, imposts, and excises" are indirect taxes in the sense of the constitution. But the difficulty still remains, to ascertain^ what taxes are comprehended under this description; and what under the description of direct taxes. It has been remarked by Adam Smith, that the private revenue of individuals arises ultimately from three different sources, rent, profit, and wages; and, that every public tax must be finally paid from some one, or all of these different sorts of revenue. He treats all taxes upon land, or the produce of land, or upon houses, or parts, or appendages thereof, (such as hearth taxes and window taxes,) under the head of taxes upon rent; all taxes upon stock, and money at interest, upon other personal property yielding an income, and upon particular employments, or branches of trade and business, under the head of taxes on profits; and taxes upon salaries under the head of wages. He treats capitation taxes and taxes on consumable articles, as mixed taxes, falling upon all or any of the different species of revenue. A full consideration of these different classifications of taxes belongs more properly to a treatise upon political economy, than upon constitutional law.

§ 949. The word "duties" has not, perhaps, in all cases a very exact signification, or rather it is used sometimes in a larger, and sometimes in a narrower