Or, to illustrate in another way what I mean: The great pyramid of Gizeh is composed of layers of masonry, the bottom layer, of course, supporting all the rest. Could we by some means gradually contract this bottom layer, the upper part of the pyramid would for some time retain its form, and then, when gravitation at length overcame the adhesiveness of the material, would not diminish gradually and regularly, but would break off suddenly, in large pieces. Now, the industrial organization may be likened to such a pyramid. What is the proportion which in a given stage of social development the various industries bear to each other, it is difficult, and perhaps impossible, to say; but it is obvious that there is such a proportion, just as in a printer’s font of type there is a certain proportion between the various letters. Each form of industry, as it is developed by division of labor, springs from and rises out of the others, and all rest ultimately upon land; for, without land, labor is as impotent as would be a man in void space. To make the illustration closer to the condition of a progressive country, imagine a pyramid composed of superimposed layers—the whole constantly growing and expanding. Imagine the growth of the layer nearest the ground to be checked. The others will for a time keep on expanding—in fact, for the moment, the tendency will be to quicker expansion, for the vital force which is refused scope on the ground layer will strive to find vent in those above—until, at length, there is a decided overbalance and a sudden crumbling along all the faces of the pyramid. That the main cause and general course of the recurring paroxysms of industrial depression, which are becoming so marked a feature of modern social life, are thus explained, is, I think, clear. And let the reader remember that it is only the main causes and general courses of such phenomena that we are seeking to trace or that, in fact, it is possible to trace with any exactness. Political economy can deal, and has need to deal, only with general tendencies. The derivative forces are so multiform, the actions and reactions are so various, that the exact character of the phenomena cannot be predicted. We know that if a tree is cut through it will fall, but precisely in what direction will be determined by the inclination of the trunk, the spread of the branches, the impact of the blows, the quarter and force of the wind; and even a bird lighting on a twig, or a frightened squirrel leaping from bough to bough, will not be without its influence. We know that an insult will arouse a feeling of resentment in the human breast, but to say how far and in what way it will manifest itself, would require a synthesis which would build up the entire man and all his surroundings, past and present.