Henry C. Carey, the American apostle of protectionism, defines capital as “the instrument by which man obtains mastery over nature, including in it the physical and mental powers of man himself.” Professor Perry, a Massachusetts free trader, very properly objects to this that it hopelessly confuses the boundaries between capital and labor, and then himself hopelessly confuses the boundaries between capital and land by defining capital as “any valuable thing outside of man himself from whose use springs a pecuniary increase or profit.” An English economic writer of high standing, Mr. Wm. Thornton, begins an elaborate examination of the relations of labor and capital (“On Labor”) by stating that he will include land with capital, which is very much as if one who proposed to teach algebra should begin with the declaration that he would consider the signs plus and minus as meaning the same thing and having the same value. An American writer, also of high standing, Professor Francis A. Walker, makes the same declaration in his elaborate book on “The Wages Question.” Another English writer, N. A. Nicholson (“The Science of Exchanges,” London, 1873), seems to cap the climax of absurdity by declaring in one paragraph (p. 26) that “capital must of course be accumulated by saving,” and in the very next paragraph stating that “the land which produces a crop, the plow which turns the soil, the labor which secures the produce, and the produce itself, if a material profit is to be derived from its employment, are all alike capital.” But how land and labor are to be accumulated by saving them he nowhere condescends to explain. In the same way a standard American writer, Professor Amasa Walker (p. 66, “Science of Wealth”), first declares that capital arises from the net savings of labor and then immediately afterward declares that land is capital. I might go on for pages, citing contradictory and self-contradictory definitions. But it would only weary the reader. It is unnecessary to multiply quotations. Those already given are sufficient to show how wide a difference exists as to the comprehension of the term capital. Any one who wants further illustration of the “confusion worse confounded” which exists on this subject among the professors of political economy may find it in any library where the works of these professors are ranged side by side.