1. It has been seen in the preceding chapter that there are three distinct species of Exchangeable, or Economic, Quantities, symbolised by the terms Money, Labour, and Credit, the various interchanges of which give rise to Six different kinds of Exchange. These constitute the science of Economics, or Political Economy, in its most modern definition. It has also been said that the Value of any Economic Quantity is any other Economic Quantity for which it can be exchanged. To examine these six species of exchange with all their ramifications, would be a complete treatise on Economics. In the present work we have only to do with two out of the six species of exchange, viz., the exchange of Money for Credit, or Debts, and the exchange of Credit, or Debts for Credit, or Debts, which constitutes the business of Banking. We must now investigate the Theory of Value, which must be equally applicable to all Economic Quantities, and to all the six species of exchange.

The complete Theory of Value comprises the following: -

1. The Definition of Value.

2. The Origin, Source, or Cause of Value.

3. The General Law of Value.

We must now examine each of these separately, and though we wish to avoid controversy as much as possible, we cannot avoid noticing some misconceptions which are still very prevalent, as they have done so much to obscure the Theory of Credit in recent times.