Experience, however, shows that neither a state nor a bank ever have [sic] had the unrestricted power of issuing paper money without abusing that power; in all states, therefore, the issue of paper money ought to be under some check and control; and none seems so proper for that purpose as that of subjecting the issuers of paper money to the obligation of paying their notes either in gold coin or bullion.
David RicardoIt is here we come to the heart of the matter. The economic principle of comparative advantage', 'a country may, in return for manufactured commodities, import corn even if it can be grown with less labour than in the country from which it is imported
David Ricardo