In primitive traffic the economic man is awaking but very gradually to an understanding of the economic advantages to be gained by exploitation of existing opportunities of exchange. His aims are directed first and foremost, in accordance with the simplicity of all primitive culture, only at what lies first to hand. And only in that proportion does the value in use of the commodities he seeks to acquire, come into account in his bargaining. Under such conditions each man is intent to get by way of exchange just such goods as he directly needs, and to reject those of which he has no need at all, or with which he is already sufficiently provided. It is clear then, that in those circumstances the number of bargains actually concluded must lie within very narrow limits. Consider how seldom it is the case, that a commodity owned by somebody is of less value in use than another commodity owned by somebody else! And for the latter just the opposite relation is the case. But how much more seldom does it happen that these two bodies meet! Think, indeed, of the peculiar difficulties obstructing the immediate barter of goods in those cases, where supply and demand do not quantitatively coincide; where, e.g., an indivisible commodity is to be exchanged for a variety of goods in the possession of different person, or indeed for such commodities as are only in demand at different times and can be supplied only by different persons! Even in the relatively simple and so often recurring case, where an economic unit, A, requires a commodity possessed by B, and B requires one possessed by C, while C wants one that is owned by A ó even here, under a rule of mere barter, the exchange of the goods in question would as a rule be of necessity left undone.