Debt: The First 5,000 Years by David Graeber

Heard about this one from Junseth when he was still doing Bitcoin Uncensored.

It should be taken with a grain of salt -- it is written by an anthropologist; not an economist. Look at it as if Howard Zinn wrote a economics book.

But it's pretty fascinating to read an alternative perspective on the history of economics that deviates from the traditional "First there was barter, then there was money, then there was credit". Ancient Sumerians were on a debt-based accounting system by like 3500BC. Primitive monies actually co-existed, instead of competed, for different purposes (sacred and secular). It's pretty interesting stuff!