The textbook story says money replaced clumsy barter, wheat for cows and goats for shoes. Anthropologists have found no society that actually worked that way. Drawing on David Graeber’s work on debt, this episode argues that early communities ran on favors and reciprocal obligation, and that money began as a way to count those debts once villages grew too large for memory. The evidence is older than any coin: 30,000-year-old tally sticks and the Ishango bone, a 20,000-year-old baboon thigh bone covered in matched marks.

From there the story moves through each new answer to the problem of trust. Mesopotamian temples at Uruk issued clay tokens against deposited barley. Lydia minted electrum coins in the 7th century BC, and rulers soon learned to debase them. Song Dynasty China printed paper notes when copper ran short, England split hazel tally sticks, and London goldsmiths invented fractional reserve banking. The episode ends with the 1971 Nixon shock, fiat currency, and the public ledger of Bitcoin.

• The touchstone let merchants test a coin by comparing the streak it left on dark stone with streaks from needles of known purity.
• Athens used silver from Laurium, mined by slave labor, to standardize its owl coin and fund a fleet.
• The English Treasury paid creditors with its half of a split tally stick, handing over the right to collect a future tax debt.
• Goldsmith bankers issued more paper receipts than they held in gold, much like an airline overbooking a flight, which created the risk of a bank run.
• Fiat money holds its value through legal tender laws and the requirement that taxes be paid in it, while a blockchain solves double spending through shared consensus.