There are words that no longer sting, because we have forgotten how they once did. Usury is one of them.
Today, interest is a number on a contract, a percentage buried in a bank statement. It is calculated, expected, normalized. But once — for centuries — it was feared. Not because people didn’t understand money, but because they did. Because they knew that to put a price on time, on need, on desperation, was to cross a line both moral and sacred.
And alongside this, the question of the just price — the idea that not all prices are right simply because they are agreed upon. That fairness is not found in the mechanics of exchange, but in the heart of the transaction.
In the quiet vaults of Scholastic thought, these questions were not marginal. They were central. They pulsed at the intersection of wealth and conscience. They asked, again and again: What is rightful gain? What is theft disguised as trade? Where does profit end and exploitation begin?
We live in a time of abstraction. But these are not abstract questions. They are as urgent now as they were then.
When Lending Becomes a Wound
To the ancient world — and the medieval one that followed — usury was not simply high interest. It was the very act of charging interest on a loan. It was the idea that money, which bears no fruit on its own, could multiply simply by passage of time.
Aristotle called it “unnatural.” The early Church called it sin. Usury, they believed, was the commodification of time — God’s time — and the exploitation of human vulnerability.
It was not that they misunderstood lending. They understood it all too well. They saw how the poor borrowed to survive, not to invest. They saw how interest turned misfortune into bondage. They saw how wealth, once lent, returned bloated — and how this bloat did not feed the world, but suffocated it.
To lend with interest, in their eyes, was not enterprise. It was domination.
Thomas Aquinas: The Architecture of Moral Exchange
In the 13th century, Thomas Aquinas offered one of the clearest formulations of this moral framework.
He distinguished between use and consumption. A loaf of bread, once used, is consumed. Money, however, is a tool — its use is its consumption. To charge for its use is to charge twice — once for the loan itself, and again for what the borrower does with it.
But Aquinas was not rigid. He allowed that a lender might be compensated for certain real losses — damnum emergens (actual loss) or lucrum cessans (foregone gain). Yet this was not profit. It was restitution.
What matters, again and again, is intention. Is the lender helping or exploiting? Is the price fair, or is it feeding on the borrower’s need?
To Aquinas and the Scholastics, economy was not a realm of neutrality. It was a field of moral weight.
The Just Price: A Sacred Equilibrium
Alongside usury, the idea of the just price was another cornerstone of medieval economic ethics.
What makes a price just? Not simply mutual agreement. For the Scholastics, a just price reflected something deeper:
– the cost of production,
– the labor and risks involved,
– the necessity of the good,
– and the welfare of the community.
Prices should reflect real value, not market manipulation. Charging more in a time of desperation — what we now call price gouging — was condemned as theft. Hoarding was a sin. The economy, they believed, existed to sustain human life, not to squeeze it.
Again, the concern is not with exchange in itself, but with its context. With the dignity of both buyer and seller. With balance.
This was not economics as mechanics. It was economics as ethics.
The School of Salamanca: Rethinking Time
By the 16th century, the world had changed. Trade had globalized. Cities swelled. Capital began to move in ways the ancients could not have imagined.
The School of Salamanca — a group of Spanish theologians — took up the challenge. Could lending be just if it enabled enterprise? Could interest be acceptable in a world of risk, inflation, and opportunity cost?
Scholars like Domingo de Soto and Luis de Molina began to refine the old prohibitions. They allowed for interest in cases of uncertainty or loss, gradually carving out space for credit-based commerce — without discarding the moral lens.
They walked a narrow line: embracing complexity, but refusing to surrender justice.
Their legacy lives on — not in the algorithms of finance, but in the question they refused to let go of: When does lending serve, and when does it enslave?
What We’ve Forgotten
Modern markets rarely speak in the language of justice. Prices are signals. Interest is cost. Credit is lifeblood. But beneath the technical language lies the same terrain the Scholastics walked:
– Why does money grow while time passes?
– Who bears the burden of debt?
– When does price reflect value — and when does it mask extraction?
To revisit the ideas of usury and just price is not to turn back the clock. It is to reclaim a vocabulary that can name what we too often leave unnamed:
That debt can crush.
That prices can lie.
That systems can function and still do harm.
Toward a Moral Reckoning
Perhaps our time needs a new Scholasticism — not to revive medieval doctrine, but to restore ethical depth.
To ask:
– Is this interest rate just, or is it predatory?
– Is this price fair, or is it profiteering?
– Is this economy growing wealth, or widening injustice?
We cannot answer these questions with spreadsheets alone. We need something deeper. A vision of the human. A memory of justice. A sense that behind every number is a life.
Because the price of bread is never just bread.
And the cost of credit is never just math.
It is memory. It is morality. It is power.
And until we see that again, our markets may run — but they will not heal.
Our banks may grow — but our neighbors may not breathe.
The Scholastics, in their quiet, candlelit halls, were not behind their time.
Perhaps they are ahead of ours.