Demonstration of the fact that search for the determinants of the objective exchange value of money always leads us back to a point where the value of money is not determined in any way by its use as a medium of exchange, but solely by its other functions, prepares the way for developing a complete theory of the value of money on the basis of the subjective theory of value and its peculiar doctrine of marginal utility.

Now, the first part of the problem of the value of money having been solved, it is at last possible for us to evolve a plan of further procedure. We no longer are concerned to explain the origin of the objective exchange value of money; this task has already been performed in the course of the preceding investigation. We now have to establish the laws which govern variations in existing exchange ratios between money and the other economic goods.

The central element in the economic problem of money is the objective exchange value of money, popularly called its purchasing power. This is the necessary starting point of all discussion; for it is only in connection with its objective exchange value that those peculiar properties of money that have differentiated it from commodities are conspicuous.

It follows from what has been said that there can be no discussion of the problem of the value of money without consideration of its objective exchange value. Under modern conditions, objective exchange value, which Wieser also calls Verkehrswert (or value in business transactions), is the most important kind of value, because it governs the social and not merely the individual aspect of economic life.

The theory of money must take account of the fundamental difference between the principles which govern the value of money and those which govern the value of commodities. In the theory of the value of commodities it is not necessary at first to pay any attention to objective exchange value. In this theory, all phenomena of value and price determination can be explained with subjective use-value as the starting point.

It has been shown that under certain conditions, which occur the more frequently as division of labor and the differentiation of wants are extended, indirect exchange becomes inevitable; and that the evolution of indirect exchange gradually leads to the employment of a few particular commodities, or even one commodity only, as a common medium of exchange. When there is no exchange of any sort, and hence no indirect exchange, the use of media of exchange naturally remains unknown.

Superficial critics of the capitalistic economic system are in the habit of directing their attacks principally against money. They are willing to permit the continuance of private ownership of the means of production and consequently, given the present stage of division of labor, of free exchange of goods also; and yet they want this exchange to be achieved without any medium, or at least without a common medium, or money. They obviously regard the use of money as harmful and hope to overcome all social evils by eliminating it.

It is usual to divide economic goods into the two classes of those which satisfy human needs directly and those which only satisfy them indirectly: that is, consumption goods, or goods of the first order; and production goods, or goods of higher orders.1  The attempt to include money in either of these groups meets with insuperable difficulties.

We have not undertaken this investigation into the relationship between money and production goods merely for its terminological interest. What is of importance for its own sake is not our ultimate conclusion, but the incidental light shed by our argument upon those peculiarities of money that distinguish it from other economic goods. These special characteristics of the common medium of exchange will receive closer attention when we turn to consider the laws that regulate the value of money and its variations.

By social or productive capital Böhm-Bawerk means the aggregate of the products intended for employment in further production.19  If we accept the views expounded above, according to which money cannot be included among productive goods, then neither can it be included in social capital.