In the theory of commodity money, money is determined as commodity. This prescription, 'money is commodity', entails that even if the 'money' is no longer money, the 'money' is still commodity. But if we strip its function from today's 'money', it is no longer commodity. After the stripping, we get a mere paper, poor metal and the number written on bankbook. From this point, the persuasion of the theory of commodity money is simply questioned. But the theory of commodity money has two contents. One is to consider about essence of money. Another is to consider about reason for existence of money. The question about the theory of commodity money is turned to consideration about the essence of money. In general opinion, this question is the question against metallism. Another content of this theory, consideration about reason for existence of money, treats of logical generation of money. It insists that money generates spontaneously in the market. In this logic, the generation of money is considered from the perspective of exchange itself. As a result, we get commodity money, as it were, automatically. But this prescription, 'money is commodity', is different from the prescription, 'money is commodity', which is drawn from the consideration about essence of money. Obviously these two prescriptions are same phrase. But the content of these prescriptions are different. The matter is how we interpret these same and different prescriptions. In this paper, I consider the theory of commodity money from the viewpoint of reason for existence of money. And this theme is considered as generation of money. In this framework, as I have already mentioned, certain commodity becomes money automatically. But it does not mean that the essence of money is commodity. The theory of commodity money, as reason for existence of money, is the description of human nature, which is given conditions of private property and social division of labor. If say in other words, it describes principle of market. In other theory, 'contract' is the moment of reason for existence of money. It insists that money is the external existence of market. So, money is not able to generate from exchange itself. From this point, this theory requests the power of generating money for 'contract'. In this paper, I try to unify with this theory and the theory of commodity money. It is a trial to unify with internal generation of money and external generation of money. I base internal generation on external generation. It comes from interest to the awareness of real economic phenomenon. If there is the principle behind various economic phenomena, we will be able to comprehend them on the basis of the principle. We should be able to grasp real economy as an amalgam the principle and factors, which bring various phenomena. On this hypothesis, in this paper, I aim to consider influence of the principle upon reason for existence of money.
