Economic theory is built on the flawed premise of a rational, economically-motivated individual. Financial historian Russell Napier argues this ignores psychology, sociology, and politics, making financial history a better guide for investors. The theory's mathematical edifice crumbles without this core assumption.

Measured by access to consumer goods, wealthier parts of Europe did not regain the standard of living enjoyed by ordinary Romans until the 1700s. A typical Roman owned more varied types of dishes than their 17th-century English counterpart, highlighting Roman consumerism's height.

Adam Smith is often miscast as the originator of laissez-faire economics. In reality, his work viewed markets as embedded in human-created institutions like law and power structures, a perspective closer to institutionalism than modern neoclassical theory. The phrase "invisible hand" appears only once in his 800-page book.

Post-WWII, economists pursued mathematical rigor by modeling human behavior as perfectly rational (i.e., 'maximizing'). This was a convenient simplification for building models, not an accurate depiction of how people actually make decisions, which are often messy and imperfect.

The original study of economics was "political economy," which understood the economy as inseparable from politics, law, and history. The late 19th-century rise of neoclassical thought deliberately separated these fields, treating the economy as a natural, pre-political system, akin to a law of physics like gravity.

The Romans were masters of making existing Greek technologies, like water-powered devices, bigger and more widespread. However, they were not great inventors of new concepts like the spinning wheel, and their scaled-up technology rarely trickled down to benefit small, ordinary farms.

The fall of Rome was primarily an economic and demographic event. A long-term decline in population, starting as early as the 2nd century, combined with massive inflation, broke the crucial feedback loop between consumption, production, and the state's ability to collect taxes.

The Roman Empire lacked modern, impersonal banking systems. "Banks" were typically run by a single family, making the distinction between borrowing from a bank versus from family much less clear. This structure explains the persistence of decentralized, relationship-based lending.

For a period, a perverse norm developed in economics where the 'better' academic model was one whose theoretical agents were smarter and more rational. This created a competition to move further away from actual human behavior, valuing mathematical elegance and theoretical intelligence over practical, real-world applicability.