states that it was introduced by agreement (κατὰ συνθήκην); that, owing to this, it is called νόμισμα, because its value is not natural but legal; and that it may, at any time, be changed or made useless.691 In the light of other evidence, however, it seems probable that he here meant to emphasize merely the fact that the general agreement of a community is necessary before anything can be used as a symbol of demand. In stating that it may be made useless, he probably referred to money itself, rather than the material of it, which is, of course, true. His determined opposition to the mercantile theory of money, as the basis of false finance, caused him to appear to subscribe to the opposite error.
That, in actual fact, he did recognize the necessity of intrinsic value as an attribute of money is clearly evidenced by another passage, where he specifies it. He says that the material chosen as money was a commodity and easy to handle.692
This can mean only that it is subject to demand and supply, like any other object of exchange. This inference is substantiated by another passage, which declares that the value of money fluctuates, like that of other things, only not in the same degree.693
Moreover, in his enumeration of the diverse kinds of wealth, money is regularly included.694
It seems evident, therefore, that he did not fall a victim of either error, but recognized that, though money is only representative wealth, yet it is itself a commodity, whose value changes with supply and demand, like other goods.695
Since he understood the use of money as a standard of deferred payments, he also saw clearly the necessity of a stable monetary standard.696