But division of Labor would be useless were it not for Trade. Each of those frontiersmen must trade his share in the other’s habitation for the other’s share in his habitation; each of those messengers must exchange his claim to compensation for delivering one of the other’s two messages for the other’s claim to compensation for delivering one of his. This, then, is the sum and substance of Trade in Economics--adjustments of compensation for specialized Production through division of Labor. The effect is magical. By division of Labor and Trade the single individual becomes a vital part of a comprehensive human organism, of a greater man, of the Social or Economic Man--a Man of almost infinite Economic powers. Those two kinds of Economic energy, making and trading, permeate the multitudinous phenomena of that Productive Process in the course of which Man draws forth Artificial Objects from and upon Natural Resources, for the satisfaction of human desires; or, to use the technical Economic terms, in the course of which Labor produces Wealth from and upon Land. 3--_Utility, Value, Money, Price, Banks_ In connection with division of Labor and Trade we are brought into contact with the phenomena of Economic Utility and Economic Value. Utility is an absolute term indicative of essential desirability. Value is a relative term indicative of the relative Utility of commodities; or, more precisely, of the degree of desirability of one variety of Labor or Land or form of Wealth in comparison with other varieties. One variety of Labor or of Land or of Wealth may be twice as desirable as another, unit for unit, in which case one unit of the former will exchange in Trade for two units of the latter. Thus the relative Utility of a Commodity is indicated in Trade by its Value. For measuring Value in all its variations from least to greatest and comparing these in the Productive Process, the Economic instrumentality is Money, that surface layer of Economics through which we passed in our exploration down to the Basic Facts; and the synonym for Value in terms of Money is Price.