Usury is defined as the charging of excessive interest. But no word exists to describe too little interest. — Edward Chancellor

In the beginning was the loan and the loan carried interest. Well, this may have been the case. We don't know for sure, but it's now widely believed that the earliest transactions were for credit rather than barter. We do know that the Mesopotamians charges interest on loans before they discovered how to put wheels on carts. Interest is much older than coined money, which only originated in the eighth century BC... There is no evidence for this barter-to-money myth. On the contrary, it seems likely that credit antedated money and that the earliest forms of credit bore interest.