I've been thinking a lot about the implications of debt so I turned to financial history.
So I found this book Debt and Economic Renewal in the Ancient Near East. It's a collection of well-written essays about debt in (mostly) Mesopotamia. The ideas of credit, debt, and private ownership of land (obviously related to the first two ideas) were just getting started.
If you invent debt, then un-repayable debt will soon follow. Mesopotamia dealt with this problem with the concept of the debt jubilee - the forgiveness of debt by the king, usually the first act of the new king to engender goodwill.
But was it an altruistic gesture? We can never know, but scholars speculate that jubilee was more about keeping men available for army service instead of forever laboring on their debt.
The main heading for our books on debt is located here. Features research on the history of debt and primary resources.