Every transaction is recorded twice, as a debit in one account and a matching credit in another, so that total debits must always equal total credits. This internal symmetry turns the books into a self-auditing system: a mismatch signals an error, and the balance sheet can be reconciled independently of any outside authority.
In 1494 the Franciscan friar and mathematician Luca Pacioli included a section on Venetian merchant bookkeeping in his encyclopedic mathematics work 'Summa de Arithmetica', printed on Gutenberg's new press. He did not invent the method, which Venetian traders already used, but his printed codification spread it across Europe and made him the figure history credits as the father of accounting.
By producing a clear running figure for profit and capital, double-entry gave merchants a precise measure of whether an enterprise was growing or shrinking, abstracting business performance into a single quantified result. Gleeson-White argues this capacity to calculate and pursue profit as a number was a condition for the rational, accumulation-driven behavior characteristic of modern capitalism.
Because conventional national accounts like GDP count only priced market transactions, unpaid work and depletion of natural resources register as nothing or even as gains when sold off. Seeing the economy through its ledgers reveals that the boundaries of measurement silently define what a society treats as valuable and what it renders invisible.