The essence of money consists in its function and not in its form. Cattle have been used as money, and so have sea-shells. Gold served for many centuries within countries and still does in international transactions. But in modern advanced economies, money features chiefly as bank deposits, and, to a much lesser extent, as bank notes and coin. Payments are made by transferring deposits, usually by writing out a cheque, or by handing over note and coin. Despite their intrinsic lack of worth, anyone will accept these assets, partly because he knows that others will accept them from him, and partly because he is legally bound to accept notes (into which deposits can be cashed on demand) in settlement of a debt. The total quantity of money within present-day economies, whether private enterprise or collectivist, is under the ultimate control of their governments. The machinery of this control, and the

whole process of evolution by which money assumed its present form, although interesting and important, will be left out of our discussion.