Definition
Money is a system of mutual trust whose tokens — coins, banknotes, ledger entries — let strangers transact at scale. It is not, in Harari's account, a commodity with intrinsic value. It is a shared story powerful enough that almost everyone is willing to accept the token today on the belief that almost everyone else will accept it tomorrow.
Money's power lies in conversion. A bag of grain becomes a tax payment becomes a soldier's wages becomes a temple offering becomes a loan becomes a ship's cargo. No barter system, no kinship network, and no religious code can move value between unrelated people across such categories with this fluency.
Why it matters
How it works
A money system works the moment enough people agree that a particular token represents value. Early systems used cattle, barley, cowries, then precious metals — items whose physical scarcity made the trust easier to extend. Coinage standardised the token; writing standardised the record; banking built credit on top of both. Modern fiat currency drops the commodity backing entirely and operates purely as collectively underwritten promise.
Harari's striking move is to compare money to monotheism. Both are universal-claim imagined orders; both demand and produce shared trust across vast and unrelated populations; both make it possible to do at planetary scale what otherwise would only work in a village.