Since its very inception, money has served the purpose of accumulation, i.e. saving and investing value. For a long time, this function was limited to precious metals as a tangible form of money. Fiat money emerged with the advent of credit. Medieval states needed money for their projects, especially to wage war and pay mercenary armies. They obtained money by borrowing it from creditors. However, political property is the prerogative of the state, and the sovereign often considered what he had borrowed as his property, i.e. he did not repay the debt. Creditors, suffering from the arbitrariness of the state, developed a new form of property—economic or private:
“Montesquieu describes here first how commerce was hampered by the prohibition of interest-taking by the church and was consequently taken up by the Jews; how the Jews suffered violence and constant extortions at the hands of nobles and kings; and how eventually they reacted by inventing the bill of exchange (lettre de change). The final portion of the chapter draws striking conclusions: ‘…and through this means commerce could elude violence, and maintain itself everywhere; for the richest trader had only invisible wealth which could be sent everywhere without leaving any trace. … In this manner we owe … to the avarice of rulers the establishment of a contrivance which somehow lifts commerce right out of their grip’” (Hirschman 1977, p. 72).
The transition from political to private property, i.e. the emergence of bills of exchange and the development of sovereign debt, led to monetary transactions as a special type of commodity transactions in which it is not goods that are traded, but money itself. The payment for money is interest.
“… Money as a whole takes on a very distinctive character in specific monetary transactions; that is, when it does not function as a medium of exchange to other objects, but as the central content, as the object of a transaction sufficient to itself. Money is an end in itself in the purely bilateral financial operation not only in the sense that it has suspended its qualities as a means, but also in the sense that it is, from the outset, the self-sufficient center of interest, which also develops its own distinctive norms and, at the same time, completely autonomous qualities and a corresponding technique” (Simmel 2004, p. 309).