The Ishango Bone, a bone tool discovered in the Congo and dating to around 18,000 BCE, contains notches that may record counting or tallying, suggesting early forms of record-keeping may have emerged earlier than often assumed. McWilliams suggests that humans may have served as a kind of “base currency,” making slavery money’s original sin.

For over 400,000 years, fire dominated human development. Anthropologist James C. Scott describes humans as a “pyrophyte” species, shaped by fire’s ability to cook food, clear land, and create social centers. Around 12,000 to 9,000 BCE, global warming prompted the independent emergence of agriculture in several regions. Despite this revolution, humanity’s population grew only from 4 million in 10,000 BCE to 5 million by 5,000 BCE, as animal diseases jumped to humans, causing devastating pandemics.

After 5,000 BCE, evolved immunity allowed populations to expand rapidly, reaching 100 million by the Common Era. British anthropologist Robin Dunbar’s research shows that human brains evolved for small nomadic groups, which made it necessary to invent social technologies—language, law, religion, and money—to manage the complexity of large agricultural settlements. Grain cultivation created storable surpluses that established systems of value, with the Sumerian shekel equivalent to a bushel of barley. The granary functioned as a central storehouse, managing surpluses and distribution and enabling taxation. Grain-based money initiated humanity’s transformation from a species defined by fire to one shaped by money.

More than 5,000 years ago, a Mesopotamian man named Kushim borrowed barley at a 33.33% annual interest rate to brew beer, facing high stakes where he or his children could become collateral if he defaulted. The interest rate introduced a major innovation: It turned money into a tradable commodity with its own price and allowed people to connect present economic reality to future scenarios. This abstraction enabled borrowers to use future income for present spending, preventing hoarding and stimulating commerce. Sumerians deployed both simple and compound interest in their sophisticated financial system.

Kushim held another distinction: His name, recorded in cuneiform between 3,400 and 3,000 BCE, is among the earliest recorded personal names. Writing emerged to document monetary transactions, making money humanity’s first written subject. The Mesopotamian shekel, established around 3,000 BCE, was a unit of weight, originally for grain but also used for precious metals. The Eshnunna Code of Law from the 18th century BCE lists various prices in shekels of silver, demonstrating tight state control over standardized weights.

Commerce demanded numeracy. Sumerians developed a base-60 number system because 60 is divisible by many smaller numbers, making trade calculations practical. This legacy survives in modern time measurement. A tablet from Drehem, dating to around 2,100 BCE, shows a detailed, ledger-like record that resembles a spreadsheet—a multi-year financial model for a cattle business with projections, scenarios, and profit calculations. This Sumerian financial architecture, animated by interest rates, made money dynamic. However, the next innovation made money portable: coins.

In Greek mythology, King Midas of Phrygia was granted a wish that everything he touched turn to gold. The curse backfired when his food and daughter became gold, prompting the god Dionysus to instruct Midas to bathe in the Pactolus River. The river, which carried electrum (white gold), became the wealth source for Midas’s successors, the Lydians.

The Lydians revolutionized commerce by inventing coins from this electrum around 700 BCE. Unlike top-down economies organized by hierarchy, coins enabled bottom-up market systems where prices and profits determined outcomes. Around 680 to 645 BCE, King Gyges established a state monopoly on minting, stamping coins with a lion’s head to create a universal, standardized currency—a model adopted by subsequent civilizations. This innovation distinguished between money’s issuers (the state) and users (citizens).

Greek historian Herodotus identified Lydians as the first to use coins and the first retail traders. Under King Croesus (circa 560 BCE), the Lydian Empire flourished, its capital, Sardis, becoming a major hub on east-west and north-south trade routes. Smaller coin denominations brought more people into the market economy, facilitating transactions and allowing coin-based dowries that enabled marriages between different tribes. Coins’ universal value—where a single coin purchased the same amount regardless of who spent it—represented a small step toward social mobility. Money’s organizational power, by making prices comparable across markets, simplified complex choices by providing a common denominator for valuing everything from bread to labor. This system required numeracy, nudging society toward rationality and away from superstition.

Xenophon (circa 430 to 354 BCE), born into a modest Athenian family, led 10,000 Greek mercenaries to safety after their commanders were executed following the death of their employer, Cyrus the Younger. Xenophon documented this journey in his Anabasis and later wrote Oeconomicus, what McWilliams describes as the first economics book. Juxtaposing his practical writing with Homer’s mythic epics highlights reveals a Greek intellectual shift from mythos (narrative) to logos (logical reasoning).

This transformation coincided with widespread coinage. Athens, unable to feed itself, imported three-quarters of its food by the fifth century BCE, yet its population surged 80% between 480 and 450 BCE. This growth resulted from a sophisticated financial and legal system centered on the silver tetradrachm, called the owl, which circulated for over 700 years. Minted from Laurion’s rich silver deposits, with one drachma roughly equaling a day’s labor, these coins animated a dynamic economy.

The monetized Greek world, organized around the polis (city-state), challenged traditional hierarchies. Reformer Solon established the polis as civilization’s foundation, with the agora (marketplace) at its heart—a vibrant hub where philosopher Socrates developed his questioning method. Xenophon grappled with abstract concepts like use value versus exchange value and advocated for women’s partnership in household management. This era produced democracy under Cleisthenes, though it excluded enslaved individuals and women, and spawned figures like Hippocrates and Aristotle. Athens maintained taxes below 8%, encouraging commerce.

Coins, initially minted to pay soldiers, spread as these troops spent money locally. The 500-year period from 300 BCE to 200 CE witnessed sustained economic expansion coinciding with widespread coinage. The book suggests Christianity emerged partly as a reaction to money-based societal disruptions, offering spiritual solace to those anxious about their status in an economy that created both winners and losers.

In August 79 CE, Mount Vesuvius erupted, burying the prosperous Roman port cities of Pompeii and Herculaneum. When archaeologist Giuseppe Fiorelli excavated Pompeii in 1860, he uncovered a commercial hub with mosaics celebrating profit, Egyptian emeralds, and an Indian ivory statuette—evidence of Rome’s vast trading networks. Citizens worshipped Mercury, the god of commerce, which the chapter links to both commerce and trade (from Latin roots meaning “with merchandise”). Rome’s key financial innovation was an extensive credit system built on conquest and taxation.

Emperor Vespasian, ruling around 70 CE, funded ambitious building projects like the Colosseum by broadening the tax base, even levying a tax on urine (used for its ammonia content in cleaning). When his son Titus objected to this distasteful revenue source, Vespasian retorted with the Latin phrase “pecunia non olet”—money does not smell. Rome auctioned tax-collection rights in conquered provinces to private contractors called publicani, which sold shares to Roman citizens, creating widespread financial participation in imperial expansion. Writer Polybius noted that almost every stratum of Roman society was involved in these contracts.

In 33 CE, Emperor Tiberius crushed a coup attempt led by Sejanus and punished indebted, land-speculating senators by forcing them to hold more Italian assets. This triggered a credit crisis as provincial land prices crashed and banks called in loans. Realizing the danger, Tiberius injected 100 million sesterces into credit markets, acting as an early “lender of last resort” (72). However, Rome’s monetary system relied on finite gold and silver supplies. When Emperor Nero began currency debasement, he started a dangerous trend. By 260 CE, Emperor Gallienus accelerated debasement dramatically, reducing silver content to just 4% in eight years and triggering hyperinflation. After coming to power in 284 CE, Emperor Diocletian attempted to control inflation through price caps and interest rate ceilings, which backfired by destroying lending incentives and collapsing the credit system. Historical references to Roman deposit banking disappear after this period, implying that monetary breakdown played a role in the Western Empire’s decline.