As concerns over inflation, savings and economic stability continue to dominate public debate, the roots of modern financial wisdom are too often reduced to modern, secular theories. Yet some of the most enduring principles of economic life were first articulated not by economists, but by Catholic priests, monks and theologians.

Long before capitalism was associated with Protestantism with the Weberian thesis, Catholic thinkers from the Middle Ages to the late Renaissance were already articulating the principles that would later define it — reflecting deeply on money, property, markets and human behavior. For instance, supply and demand was already grasped by Franciscan friars precisely because of their radical choice of voluntary poverty. These reflections sit at the roots of today’s Western economic life.

Here are four useful principles drawn from the rich Catholic tradition for families and entrepreneurs today as they steward resources and make decisions. These concepts point to a vision of finance grounded in responsibility, prudence and the common good.

1. Goods Need a Steward.

The question of property precedes almost every other moral reflection on economic life, and Catholic thought engages it at its deepest level. Since antiquity, thinkers have been divided between those who favored collectivism, that is common ownership — famously associated with Plato in The Republic — and those who defended private property, as Aristotle did. The Christian tradition, drawing first on Scripture and then on philosophical reflection, decisively sided with the latter, while introducing an essential moral qualification.

Few arguments are more illuminating than those of St. Thomas Aquinas in his Summa Theologiae, where he explains why private property is not only legitimate but necessary. Human beings, he observes, take better care of what belongs to them personally: “Every man is more careful to procure what is for himself alone than that which is common to many or to all.”

Private property matters because goods need a steward: someone responsible for their care, administration and fruitful use. Goods that are privately held are more diligently managed, better preserved and more productively used. In his Commentary on Aristotle’s Politics, the Angelic Doctor insists that private property also fosters temperance and charity because one can only give what one truly possesses. “When community of goods is introduced, the works of liberality are destroyed. […] It is the man who gives and distributes from his own goods who is liberal; but there is little liberality in giving what belongs to all.”

And yet, Aquinas immediately balances this with a moral requirement: Ownership may be private, but its use must remain oriented toward others. “Property should be private, but its use should be common.”

This principle of private ownership oriented to the common good became a cornerstone of Catholic doctrine. Centuries later, it would be reaffirmed in the Church’s social teaching, notably in Rerum Novarum, where Leo XIII defends the natural right to possess private property while insisting that it must serve the common good. Wealth, in this perspective, is entrusted to individuals as something to steward wisely, for the benefit of family, community and society at large.

2. Wealth Must Circulate to Bear Fruit.

Catholic tradition has long recognized that a healthy economic order presupposes the possibility to accumulate capital — savings that can be invested and put to work — standing in sharp contrast to consumerism. At the same time, from the Middle Ages onward, theologians — inspired by Aristotle’s argument that money cannot produce money — warned against the danger of “sterile wealth,” wealth that is hoarded, immobilized or withdrawn from economic life.

This intuition had already been anticipated by Franciscan thinkers in the 13th century, such as Peter John Olivi, whose Treatise on Contracts — one of the very first systematic works of its kind in medieval economic thought — offers a remarkably precise account of productive capital as opposed to idle money:

“That which, by the firm intention of its owner, is ordered to some probable profit, has not only the character of simple money, but beyond this a certain seminal character of gain, which we commonly call capital.”

For Olivi, money that is merely held remains simple money (simplicis pecuniae). But once it is ordered, by the owner’s intention, toward a probable profit, it takes on a new character: a seminal principle of gain (speciem seminalem lucri), what we call capital. Precisely because goods are meant to serve real human purposes, they are not fulfilled when they remain idle.

This insight would inspire major Catholic figures such as Bernardino of Siena, who popularized these ideas in his sermons, or Antoninus of Florence.

The spirit of this tradition that remains deeply relevant today is that wealth becomes fruitful when it circulates, when it is invested, exchanged, lent and put to work in real human activity. Capital, in this sense, is not static but relational. It connects people, enables projects and sustains communities.

3. Value Follows Scarcity and Common Estimation.

The Franciscan insight begins with the lived experiment of voluntary poverty. By renouncing ownership, the friars placed themselves in a unique position to observe the effects of their choice on society itself.

As Italian scholar Giacomo Todeschini explains in Franciscan Wealth: From Voluntary Poverty to Market Society (2009), the Franciscan ideal of poverty did not remove the friars from economic life but made visible its underlying dynamics. Their “poor use” of goods, precisely because it was restrained and non-appropriative, reduced demand and allowed resources to remain available to others. As he notes, when goods are used sparingly, “the involuntary poor will enjoy lower prices.” In concrete terms, the market registered this restraint: When the friars reduced consumption of goods such as wool, demand fell and prices eased, widening access for others.

Medieval Franciscan friars already asked themselves, why some goods and forms of work were valued more than others? Why is water — necessary for life — often cheaper than gold or spices? Why is a peasant’s labor less rewarded than that of a merchant or a scholar?

For Olivi — and later Scottish Franciscan John Duns Scotus — value does not reside in the thing itself, but in the conditions surrounding it. Scarcity, usefulness, effort, risk and the community’s estimation make a good — or a skill — precious. Foresight, organization and intellectual attention themselves become scarce goods.

Long before the law of supply and demand was formalized by James Steuart and Adam Smith in the 18th century, the logic was already there.

“The Franciscans were not the ‘first economists,’” Todeschini writes, “but rather those who made their appearance possible in later centuries.”

4. The Just Price Emerges From the Market.

While the Franciscans clarified what gives things their value, the Dominican and Jesuit theologians of the School of Salamanca in the 16th century — among them Luis de Molina and Leonard Lessius — asked a different question: How is that value translated into a price?

These thinkers argued that the “just price” (pretium iustum), instead of being imposed externally, emerges organically within the market itself.

Molina, for instance, observed that price depends on real conditions, that is the abundance or scarcity of goods, and the number of buyers and sellers. He also formulated, in his famous De iustitia et iure (“On Justice and Right”) a key monetary insight: “In equal circumstances, the more abundant money is in one place, the less its value for buying things. Just as greater supply of goods lowers their price, greater supply of money raises prices.” This reflects the broader principle that prices are not arbitrary but are the result of human interactions — supply, demand, expectations and circumstances, as can be seen when disruptions in strategic trade routes, such as the Strait of Hormuz, have an immediate impact on global prices.

At the same time, these theologians never reduced economics to pure mechanism, and markets remain embedded in a moral framework. Lessius, one of the most refined moral analysts of market life, insisted that the just price — set by common estimation in the market — must still observe the rules of commutative justice. Practices that exploit ignorance, manipulate scarcity, or harm the vulnerable remain unjust.

These four principles form a coherent vision of economic life. They remind us that finance, before being a technical matter, is profoundly human. At a time when economic debates are often polarized between narrow-minded individualism and utopian collectivism, the Catholic tradition offers a vision rooted in reality, moral responsibility, and a deep understanding of human nature. The West would be wrong to deprive itself of such a treasure.