Trade and Markets in the Early Empires  

"This remarkably modern view of the social function of money has not been sufficiently appreciated. Rodbertus realized that the transition from a "natural economy" to a "money economy" was not simply a technical matter, which resulted from a substitution of money purchase for barter. He insisted instead that a monetarized economy involved a social structure entirely different from that which went with an economy in kind. It was this change in the social structure accompanying the use of money rather than the technical fact of its use which ought to be emphasized, he thought. Had this point been expanded to include the varying social structures accompanying trading activity in the ancient world the controversy might have been resolved before it began. " --Trade and Markets in the Early Empires (1957)