[177] Pareto, in the introductory chapter of his _Cours d'Economie Politique_, defines economics in terms of the narrow abstraction which he has chosen for the explanation phenomenon, as the "science of ophelimity" (p. 6), and ophelimity is "an entirely subjective quality" (p. 4). There are two objections to this procedure: you neither completely explain your problem phenomena, nor do you exhaust the possibilities of your explanation phenomena--for the same sort of mental facts have bearing on ethical and other social problems as well as on economic problems. [178] I am indebted to Professor E. C. Hayes, of the Department of Sociology of the University of Illinois, for this distinction. CHAPTER XV SOME MECHANICAL ANALOGIES It may help the exposition if we throw the argument, briefly, into terms of the more familiar mechanical analogies, and speak of the equilibria and transformations of social forces. Of course, mechanical analogies have been used from time to time already in our discussion--psychologists themselves often find it useful to conceive of their phenomena in mechanical terms. And while, in the exposition, we shall find frequent reason to prefer our plan of conceiving society as a psychical organism, and the social forces as phases in an organic process, still certain relations may be clearer for being put into the other form. Social values may be transformed into other forms of social value--as heat may be transformed into electricity, or into motion, or motion into heat, etc. Professor Clark, with his distinction between "capital" and "capital goods," has shown how economic value may undergo constant transformation, as to its physical embodiment, and yet remain generically the same. But the possibilities of transformation are not confined to the economic sphere. We may generalize the notion. A man may use economic value to attain political power; having the political power, he may use it to get economic value back again, by direct barter and sale, if he wishes to take bribes, or by subtler, but still all too familiar means. Or, the political power may be transformed into personal prestige, if used in ways that please those whose good will means prestige. And personal influence--"live human power" (in Professor Cooley's phrase),[179] may be transformed into values of numerous sorts, into political power, into moral values--if he who has it wishes to make a propaganda--into prestige for other men, into economic value--for cannot an inspiring man command the purses of others in behalf of his plans and purposes? And may not popular confidence in a great statesman or financier in times of panic cause fears to be allayed, and values to return to goods that had lost their value? A man who has goods for which no demand exists, and which have, hence, little value, may, employing those who possess the art of creating demand to make public opinion for him by advertising, find his investment, transformed into public belief and