This episode explores how money evolved from physical goods to pure belief. It begins with the limitations of barter, where trade required both sides to want exactly what the other had. Early societies solved this with commodity money — items like cattle, shells, salt, and cocoa beans that held shared value. The invention of metal coins in ancient Lydia standardized currency with seals of authenticity, transforming money into a state-backed promise. Later, paper money emerged in China as lightweight receipts for stored wealth, shifting value from physical substance to symbolic trust. Banks and credit systems turned money into mathematical promises, and the eventual fall of the gold standard made modern currency purely fiat — backed only by government authority. Today, most money is digital, and cryptocurrencies represent a new attempt to anchor trust in code instead of governments. The episode concludes that money is not defined by what it’s made of, but by the collective belief we place in it.