When the subject of an infallible magisterium comes up, someone always raises the question of usury. Non-Catholics and certain Catholics claim that the Church has contradicted its own teaching on usury.
In a now-famous article, “Authority, Usury, and Contraception” (Cross Currents, Winter 1966), Noonan compares the Church’s teaching on usury and contraception through the centuries and draws two conclusions. He seeks to demonstrate that usury was strongly and consistently prohibited by the magisterium of the Church, whereas the prohibitions against contraception were less frequent, although still present. He also claims that the Church’s teaching on usury has changed with changing circumstances and that we should expect the same possibility for its teaching on contraception.
Noonan argues that usury is the taking of any interest on any sort of loan. He claims that the condemnation of usury, so defined, is the teaching of Scripture and that this biblical principle was taken up by the Church Fathers and later codified in the Church’s official teaching