As a statement re usury, “The Mortal Sin that Was and Now is Not” is incorrect.
Scripture, the Fathers of the Church, the decrees of councils and popes condemn the taking of interest on loans to the poor and the greed of usurers, but say nothing about the charging of interest in general.
Deuteronomy 23:20: “You may charge interest to a foreigner,” indicating that interest-taking is not presented as inherently evil or sinful. The larger ethical issue of the morality of interest-taking is not addressed in the Old Testament. Rather, interest was viewed only as a problem of social justice. The problem of commutative justice, i.e., of equivalence of value in an exchange of present for future goods, remained quite untouched (Thomas F. Divine, S.J., Interest, 10).
With free enterprise as developed by the Catholic Late Scholastics, the Church defined what is meant by usury. It is Session X of the Fifth Lateran Council (1515) that gave its exact meaning: “For that is the real meaning of usury: when, from its use, a thing which produces nothing is applied to the acquiring of gain and profit without any work, any expense or any risk.”
Consequently, as loaning money did involve loss of profit to the lender and further risk of loss from delay in returning the money loaned, this did justify interest that is just and justifiable.
Today, the term “usury” is usually reserved for taking excessive (i.e., unusually high for the economic conditions) interest on a loan because of someone’s circumstances: The greed of the lender takes unjust advantage of the weakness or ignorance of the borrower. [See *Encyclopedia of Catholic Doctrine