Ecumenical Council of Vienne (1311 – 1312)

“If indeed someone has fallen into the error of presuming to affirm pertinaciously that the practice of usury is not sinful, we decree that he is to be punished as a heretic; and we strictly enjoin on local ordinaries and inquisitors of heresy to proceed against those they find suspect of such error as they would against those suspected of heresy.”

For an interesting consideration of the Church’s teaching on this topic see: Is Usury Still a Sin? by Thomas Stork

I am not sure I am convinced by Stork’s rejection of the ‘money should only be a token’ argument. I think he is misidentifying this as an argument of the same kind as the ‘no gain can be received by reason of the contract itself in the loan of a fungible thing’ argument. The token argument essentially claims that the permitting of interest bearing loans of money as a means of gain in a society tends to invert the natural order by causing capital to accumulate without labour. It is imprudent and leads to injustice to permit  interest bearing loans of money as a means of gain. It is not always and everywhere unjust.