The human person’s social nature makes justice and the common good subjects of immense importance. St. Thomas Aquinas defines justice as “the habit whereby a man renders to each one his due by a constant and perpetual will” (Aquinas, 1948, II-II, q.58, a.1). Looking more closely at the definition, we see that justice resides in and perfects the rational will. By willing to be just we perfect our moral personhood. The essence of the virtue is to give to others what is their right by virtue of their nature as human beings. Thus, justice inclines us to think of and be attentive to our obligations to others. Justice is the virtue that allows us to shoulder the responsibilities of social life.

Usury is at the heart of the regime of capitalism (Heilbroner, 1985), our present ruling order. Usury is defined here, as the etymology of the word suggests, as the payment for the use of property. Interest is taken to mean exactly the same thing. This is at odds with today’s usage of the words. Money must always remain a useful tool. Habitat for Humanity demonstrates the possibilities of economic life characterized by charity and generosity.