3. _The uses of money make it a rent-bearing form of wealth._ The rent that money yields is in the form of convenience and economy. This is sometimes rendered directly as psychic income, as in enabling the traveler to buy his dinner, for the money thus yields gratification just as does the carriage in which he rides. One may go for a day to the seashore without a parasol and suffer from heat, or without money and suffer from hunger. In every case where money is retained for a time in possession, there is expected from it a usufruct as great as, or greater than, can be secured from anything else for which it can be exchanged. This usufruct is a net surplus, or income, yielded by a sum of money undiminished in amount up to the moment it is spent, but meantime increasing in the gratification it will help to secure. In many cases in practical business money yields gratification only indirectly, as the objective contract rent received as interest for borrowed money in business uses, or as economic rent when the use of money in business enables one to secure a larger income. Because money yields a rent men make the sacrifice involved in keeping a stock of it on hand. On this rent is based that part of the value of money that is derived from its money use. As the use of money as a standard of deferred payment, or basis of commercial obligations, does not require that it be owned by the parties writing the contract, this use of money is a free good, a sort of social by-product of the medium of exchange. When money is in use in a community, any person may draw up contracts in terms of money, borrowing and lending, buying and selling wealth, later to be repaid in other wealth or services expressed in the circulating medium. [Sidenote: The general use of money is characteristic of this age] 4. _Money may be defined as a generally accepted material means of payment and medium of exchange._ This, its primary and essential function, may appear to be less important as new modes of balancing accounts of wealth are devised. But its functions as a common denominator of values and as a standard of deferred payment are increasingly important in an advancing society. It is this expression of the value of all other things in terms of money which may well be deemed the essential characteristic of the capitalistic age. In earlier periods wealth was thought of and expressed in concrete terms; now it is expressed in money. The general use of money affects men's ways of looking at wealth and speaking of it. Without appreciating the nature and function of money, it is impossible to grasp the significance of capital in modern industry, the consideration of which we are now to enter upon. CHAPTER 14 THE MONEY ECONOMY AND THE CONCEPT OF CAPITAL § I. THE BARTER ECONOMY AND ITS DECLINE [Sidenote: Various points of view of the students regarding money]