Prof Daniel Schiffman of Ariel College in this article:
This chapter surveys the writings of medieval Jewish rabbis on usury throughout 1050-1565. These writings belonged to a few literary genres: authorized, moral/pietistic, and Biblical commentary. After surveying the moralistic condemnations of usury by medieval rabbis, I illustrate three theoretical approaches to the lender’s authorized obligation to return curiosity to the borrower (submit facto), that are implicit in medieval Jewish authorized writings: novel definition of theft, financial and quasi-ritualistic. I present examples of rabbinically-sanctioned circumventions of the usury ban by way of a Gentile middleman, and new rabbinic leniencies concerning loans of produce, shopping for on credit score, mortgages and investments. These circumventions and leniencies had been primarily based on radical reinterpretations of Jewish Legislation. I conclude that there was a hanging distinction between the cruel moralistic condemnations of usury in medieval rabbinic thought, and the authorized flexibility demonstrated by the medieval rabbis, who permitted circumventions of the Jewish usury legal guidelines as concessions to the realities of business life.