"The reasons why anthropologists haven't been able to come up with a simple, compelling story for the origins of money is because there's no reason to believe there could be one. Money was no more ever "invented" than music or mathematics or jewelry. What we call "money" isn't a "thing" at all; it's a way of comparing things mathematically, as proportions: of saying one of X is equivalent to six of Y. As such it is probably as old as human thought."