fore, visible expression of the abstract relationships, by diagrams, or by any figures which represent the abstract in a concrete form, will be of very considerable service to the ordinary student. This matter seems to me to be of such practical importance in teaching that it will be worth while to illustrate my meaning by a few examples:
(a.) Since material wealth comprises all things that have value; since 
capital is only that wealth employed in reproduction, and not used by the owner himself; and since money is that part of wealth in circulation aiding in the transfer of goods the relations between the three may be expressed to the commonest apprehension by some such device as the following, in which the area of circle A represents the amount of wealth; B, the capital saved out of the total wealth; and C, the money by which goods are transferred only that part of circle C being capital which, inside of circle B, is being used as a means to production.
Again (b), it is seen that different classes of laborers, arranged according to their skill, form, as it were, social strata, of which the largest and the poorest paid is composed of the unskilled laborers at the bottom. This may be shown to the eye at once by the sections of a pyramid, in which A represents the largest and least paid class; B, C, and D, etc., the better-educated, and relatively more skillful laborers; ending finally in the few, at the top, of the most competent executive managers. Now, if A were to become as fully skilled as B, and competition
should become free between all members of A and B; and if this were to go on in the same way to include C the effects of this breaking down of the barriers which hinder competition might be illustrated by the following changes in the above pyramid: the areas of A, B, and C may be thrown together into one area within the whole of which movement and choice is perfectly free to the laborer, and wherein wages are in proportion to sacrifice. This can be done by striking out the lines of division between A, B, and C, and by representing the change by the area included between the base and the dotted lines.
Examples might be continued in illustration of my method, but these must suffice. By this means there can be planted inside even the
