Usury
Calvin also had insights into the workings of economics. It is his understanding of "usury" that interests us here. Calvin was part of a society that had forbidden the lending of money at interest for 750 years (since the council of Nicaea in 775). During that period many laws were passed against usury but as many ways around the law were found. It is in this context that Calvin brings new insight into society. Taking interest on loans was officially banned by canon law, but in practice was accepted by the community. In Geneva prior to the Reformation, interest rates were set at 5% per 3 months (Bieler 55).
By 1544 Calvin had "formulated a doctrine about lending money at interest" (55). According to Bieler, Calvin had been set free from the traditional views held by the medieval theologians. Calvin was no longer bound to the traditional views of the past and so was free to develop his own biblical ethics concerning the lending of money (56).
Turning to Scripture, Calvin found many instances in which the lending at interest was forbidden. These would have been the same passages to which canon law appealed; yet Calvin's interpretation was new, even revolutionary. Calvin allowed for the lending of money at interest. By applying new hermeneutical insights Calvin learned that the banning of usury was in relation to lending to the poor. God, according to Calvin, does not want His people to be tightfisted to the poor. In his commentary on the law Calvin interprets the ban on interest in Exodus 22:35 to be a command of charity to the poor and not a total ban on taking interest (Comm. Last Four Books of Moses, vol. 3, 126). In his commentary on Psalm 15:5 Calvin asks the question "Whether all kinds of usury are to be put into this denunciation, and regarded as alike unlawful" (Comm. on Psalms, 212). Again, Calvin points to the role of the rich and the necessity of kindness to the poor but goes on to say that a total ban on interest is not what the psalmist is advocating. If there is a total ban, the man in need of money, who will be sinning by borrowing money, will be "rendered bolder by despair, and may rush headlong into all kinds of usury . . ." (212).
However, Calvin cannot cast off the perception of the moneylender as a terrible man. He agrees with Cato that a moneylender is not much better than a murderer, for they are both "bloodsuckers." It is because those who lend money tend to turn to evil and lose all compassion for their brothers that God forbids usury (213). Calvin realizes that the lending for investment is different from lending to the poor. Therefore, he allows moneylending on a limited scale for the sake of developing business capital (Bieler 56).
Throughout his teaching on usury Calvin is painfully aware of the sinfulness of man. At every turn of phrase he points out the terrible dangers of lending money. Moneylenders turn into greedy and heartless men who will lend only to the rich, for they know they will receive a return on their investment. When lending to the poor, the moneylender plunders and devours them (Comm. on Psalms 213).
Calvin's teaching on usury is one of temperance and kindness. It is a teaching that dealt with the growing industrialization of the European city and the need for capital but still kept the biblical teaching on usury in sight. This teaching was one of compassion for the poor and steeped in a love for the neighbour.
Source:
http://spindleworks.com/library/vanpopta/calvin.htm