"Before there was money, there was debt. For more than 5,000 years, since the beginnings of the first agrarian empires, humans have used elaborate credit systems to buy and sell goods-that is, long before the invention of coins or cash. It is in this era that we also first encounter a society divided into debtors and creditors-which lives on in full force to this day. So says anthropologist David Graeber in a stunning reversal of conventional wisdom....