One of the earlier Church fathers, Clement of Alexandria specified already "the law prohibits a brother from taking usury; designating as a brother not only him who is born of the same parents, but also one of the same race and sentiments... Do not regard this command as marked by philanthropy". The litany of councils specifically repeating this practice as the most despicable is really impressive: the Council of Elvira (305-306BC), of Carthage (348), of Arles (314), or Nice (325), of Taragona (516),of Aix-la-Chapelle (789), of Paris (829), of Tours (1153), the Lateran Council (1179), of Lyons (1274), of Vienne (1311). This last one was perhaps even more sweeping than the previous ones : any rulers who would not criminally punish anybody in their realms committing usury (even if the rulers themselves did not do it!) would be excommunicated. Since the practice was often concealed beneath various devices, money lenders were compelled to show their accounts to the ecclesiastical authorities. The fifth Lateran council (1512-1517) reiterated the definition of the sin of usury as "receiving any interest on money" once again.
The very first time that the original doctrine was questioned was in 1822. A woman from Lyons, France, had received interest on money and was refused absolution unless she returned the ill gotten gains. Bishop Rhedon requested a clarification from Rome which responded "Let the petitioner be informed that a reply will be given her question when the proper time comes; ...meanwhile she may receive sacramental absolution, if she is fully prepared to submit to the instructions of the Holy See". A forthcoming resolution was promised again in 1830, and from the Office of Propaganda in 1873. This promised clarification in fact never came. The sin of usury was never officially repealed, simply forgotten. The Canon Law of 1917 (Canon #1543), still operational today, suddenly makes it obligatory for Bishops to invest "As the administrators are bound to fulfill their office with the solicitude of a good father of a family, they shall invest the surplus revenue of the church to the benefit of the church". Later still usury is redefined as "the charging of excessive interest."
The period when the Church started "forgetting" the sin of usury corresponds to a tremendous increase in the Church's own capital holdings (i.e. sources of funds), and a decline in its vast ownership of land (i.e. use of funds) in Western Europe. Estelle and Mario Carota, two Mexican Catholics, in the hope of providing relief to Latin American countries when they were reeling under the debt crisis of the 1980's, made a formal request to the Vatican to clarify its position on usury in 1985. They were informed by no less an authority than the Office of the Congregation for the Doctrine of the Faith, headed by Cardinal Ratzinger, that there had never been a new definition of the doctrine of usury.
That "there has never been any change", but that there is unfortunately not one expert left in Rome in this topic, because they all have specialized in the issues of sex and abortion instead. Their attempts at finding an expert opinion among the Jesuits, Augustinians, Dominicans, Salvatorians, and even professors of moral theology in Third World seminaries teaching theology of economic justice failed to turn up anybody who remembered the forgotten Doctrine of Usury.
—Bernard Lietaer, The Future of Money: Beyond Greed and Scarcity