Modern money: fiat or credit?

Even today, textbooks on Money, Currency, and Banking are more likely than not to begin with an analysis of a state of things in which legal tender "money" is the only means of paying and lending.... But logically, it is by no means clear that the most useful method is to start from the coin-even if, making a concession to realism, we add inconvertible government paper-in order to proceed to the credit transactions of reality. It may be more useful to start from these in the first place, to look upon capitalist finance as a clearing system that cancels claims and debts and carries forward the differences-so that "money" payments come in only as a special case without any particularly fundamental importance. In other words: practically and analytically, a credit theory of money is possibly preferable to a monetary theory of credit.