From the beginning of human history, humans have exercised dominion over the material world. ponents of nature (other than persons themselves) are resources that can be rightly used, and in some instances used up, for the benefit of persons. Through their use of things, people cause much of the material world to e property: that is, material morally tied in a special way to a particular person or persons.

However, the human dominion over the subhuman world is more basic than property. This does not mean, however, that things should be owned mon. The point of associations and mon enterprises is the flourishing of each of its individual members—that is what constitutes the flourishing of the group. Moreover, if people are to flourish, then they need to make choices and to act. This includes their choices and actions concerning the use of things. For this reason, in those fields of human activity where individuals or groups can facilitate human flourishing through the private possession and use of things, then it is just for them to do so. This includes economic activity.

The question of how earth's resources are to be used for the benefit of all is left to people to work out rationally together. The principle mon use means that any arrangement of the possession of things by individuals is to be seen as a means of mon use. For this reason, in using those goods people should consider the exterior things that they legitimately possess not only as their own, but mon in the sense that their possessions should benefit not only themselves but others as well. We can say, then, that any person's earthly good is his in the sense that he owns it, but not in the sense that he alone may use it; for insofar as he does not need it to satisfy his own needs, others should be able to use it to satisfy theirs.

Private ownership of property is the normative means by which the principle mon use is realized. For one thing, private property is essential for the development of self-reliance. Secondly, private property helps us express and develop our personalities. When we own things, we can choose to use them to express our concern for others, be it by giving people gifts or by investing in productive, job-creating industries. Thirdly, private ownership or the prospect of private ownership creates incentives for people to contribute in a wider way to the society around them. It encourages people to work, to be entrepreneurial, and to create wealth for themselves and others. Lastly, private property allows people to give direct expression of their genuine responsibility for themselves and for others.

To these moral justifications for private property, we may add the three reasons given by Aquinas to explain why appropriation of property to particular owners is morally licit and even necessary. First, individuals tend to shirk responsibilities that are nobody's in particular, and people tend to take better care of what is theirs than of what mon to everyone. Second, if everyone were responsible for everything, the result would be confusion. Third, dividing things up generally produces a more peaceful state of affairs, whilst mon things often results in tension. Individual ownership—understood as the power to manage and dispose of things—is then justified.

Aquinas did, however, insist that the use of things is a different matter. In regard to use, one is not justified in holding things as exclusively one's own ( ut proprias ) but should rather hold them mon, in the sense that, after one has satisfied one's own needs and those of one's families, one ought to use the surplus in ways that benefit others.

Sometimes this can mean literally giving something we own to people in need, the use of which results in the consumption of the good. But to share the use of one's goods with others does not necessarily presuppose that the giver discontinues his own use or ownership of that good. A person's use of his house, for example, to shelter someone in need may not actually be a case of assisting with his superfluous goods. Rather, this is an instance of a person sharing a good essential for one's own well being without giving up one's ownership of the good.

Of course, there are virtually no individuals who, having satisfied their basic needs, bury their extra wealth in the ground. Invariably, they choose to invest it. This investment is sometimes in businesses that employ people and create more wealth, which is then further invested. Sometimes it is in banks, which give others access to the capital resources they need as the material basis for their own flourishing.

To this extent, banks are one of those associations that allow people to judiciously fulfill their obligations to use their surplus wealth for mon good and thus, the flourishing of other people. As noted by Antoine de Salins and François Villeroy de Galhau, “the savings of some are used to finance the investment needs of others, in the hope that this financial circuit will play its part in attaining an optimal financial growth.”

This article was excerpted from the ing monograph Banking, Justice, and the Common Good by Samuel Gregg. It can be ordered from the Acton Institute online at acton.org.