21. The proposition that money must have value from some source other than the monetary employment does not mean, necessarily, that money must be made of precious metals, or be convertible into precious metals. The value of money is, indeed, most stable and best sustained when such is the case. But it is possible for money made of paper to have value apart from the prospect of redemption--though no clear case has been made, in the writer's opinion, for the view that this has historically occurred. But as a hypothetical possibility, my theory holds that paper money may attain a value of its own, growing out of various factors which a social psychology can explain, including law, patriotism, and custom. Social values in every sphere are imperfectly rationalized. Values which in their origin are secondary and derived may become substantial and independent of their "presuppositions." This is true of legal and moral values. It is true of the capital value of land. It may be true of paper money. This matter has been discussed in the chapters on "Economic Value" and on "Dodo-Bones." The social value theory has not the limitations of the utility theory in dealing with such cases, nor is it tied to a metallist or bullionist interpretation. Legal, moral, and patriotic factors, and the influence of social custom, all fall readily into the social value doctrine. 22. The "measure of values" function, and the "standard of deferred payments" function, need not require the actual use of money, and need not add to the value of money. The function of "medium of exchange," and other functions to be analyzed in a later chapter on that topic, do involve the actual employment of money, and are sources of value for money. 23. The quantity of money and credit are matters of high importance in economic life. They affect vitally the smooth functioning of production and exchange. While not accepting the extreme view of those writers who see in scarcity or abundance of money the primary cause of the ebb and flow of civilization, I maintain that the quantity of money and credit does make a vast difference, and that the quantity theory contention that, after a transition is effected, the only consequence of a change in the quantity of money is a proportional change in the price-level, is wholly indefensible. (Chapter on "Volume of Money and Volume of Trade.") 24. Very much of economic theory has been developed in abstraction from money. For economic statics, with its delicate marginal adjustments, on the assumption that friction is banished, that the market is fluid, that labor and capital and goods are mobile, etc., money does appear a needless complication. But the static assumptions are only possible because money and credit have smoothed the way. It is the business, the function, of money and credit to overcome "friction," to effect "transitions," to make it possible for "normal" tendencies to manifest themselves. (Chapter on "Volume of Money and Volume of Trade.")