Usury: The lending of money with an interest charge for its use; especially : the lending of money at exorbitant interest rates. (Merriam-Webster)
Are you one of the few people who ask if a faithful Catholic-Christian in good conscience may practice usury or engage in usurious practices? Now that question would pass off as something which is morally indifferent to a lot of people. Some may find the practice as fine, some may not. But why do we ask about it in the first place?
Well, why shouldn’t we ask? The teachings of the Church are for all of us and the world, and it is important to learn them—and that includes the Bride of Christ’s teaching on usurious practices.
Now what does the Church say about usury?
For starters, St. Thomas Aquinas believed that usury was against the Natural Law. Since he classified money as a consumable, then money should be treated as one would treat any other consumable. If someone gives money, that someone should not expect the doubled amount in return. That is much like you buying a person cheap, instant coffee—while expecting gourmet coffee in return.
The Bible contains something against usury in Jn. 2:14. In early Christianity, there already were writings against the practice.
For example, St. Jerome wrote on usury below:
If you gave to a prosperous person you should not have done so: but if (even so) you gave it as to a needy person, why should you demand more on the score of his being prosperous? Some lenders are wont to take small gifts of different value, not realizing that whatever is received over and above what was given is called usury and superabundance. They ought not to take more, however much it be, than was originally given by them.
Then, by Pope St. Leo the Great:
Neither do we think that it should be lightly passed over that some people, seized with the desire for filthy lucre, put out their money at usury in order to become rich thereby. And we have to complain of this not only with regard to those in clerical office but we likewise grieve to see that it holds true of lay people who wish to be called Christians. We decree that this should be severely punished in those found guilty, so that all occasion of sin may be washed away.
These two quotes from Church Fathers clearly did not find usury favorable.
The Second Lateran Council shows us an explicit condemnation of it:
We condemn that practice accounted despicable and blameworthy by divine and human laws, denounced by Scripture in the Old and New Testaments, namely, the ferocious greed of usurers; and we sever them from every comfort of the Church, forbidding any archbishop or bishop, or an abbot of any order whatever or anyone in clerical orders, to dare to receive usurers, unless they do so with extreme caution; but let them be held infamous throughout their whole lives and, unless they repent, be deprived of a Christian burial. (Second Lateran Council 13)
It is quite clear that the Church certainly condemns the practice of usury. This condemnation has its basis in scriptures, tradition, the Magisterium and common logic.
Going back to the original question on the compatibility of usury with the Christian faith, the answer is very clear: Usury and the faith don’t go together.
A rather similar post can be found here.