L. Randall Wray is a professor of Economics at Bard College and Senior Scholar at the Levy Economics Institute who is a long-term proponent of Modern Monetary Theory, a heterodox macroeconomic theory that teaches the government should not worry about accruing debt, because it is always able to print more money to service that debt. This is one of those theories that sounds too good to be true - how could it be that there’s nothing wrong with debt, and that there’s nothing stopping a country like the United States from spending as much as it wants on social services and public works projects? At the heart of the theory, the piece that makes the whole thing go, is a huge shift in the way that we understand money. Instead of seeing it as an immutable unit of exchange, MMT theorists argue that money is primarily a money of account - which is simply a ledger system for keeping track of who owes what to whom. We take apart Wray’s story of the history of money, with a detour into Medieval tally sticks, how barter systems evolve into monetary ones, and how central banking sealed our economic fate, and how debt is far more valuable than we realize.