Toward Islamo-Christian business ethics? A case study on the prohibitions of riba and usury and the morality of interest

Islamic banking has attracted attention as a possible source of inspiration for ethical renewal in the finance industry. A frequently cited attribute of Islamic banking is the prohibition of riba, often identified with interest. This identification elicits comparisons with Christianity’s usury ban and raises hopes of a shared Islamo-Christian contribution to secular business ethics through a reassessment of the morality of interest. With hopes for wider appeal, this thesis focuses on Sunni and Roman Catholic sources of authority regarding the respective prohibitions. The religious texts underlying this study are from the Qur’an and Bible, the Hadith and the Fathers of the Church, Sunni jurisprudence and the Catholic magisterium. Given the view that the audience of business ethicists comprises other philosophers and the general public, it is argued that the suitable approach for the field is based on secular reasoning. While recognizing the importance of secular argumentation in the business ethics, this thesis proposes and employs a framework that invites religions to lend greater acceptability to secular argumentation and to provide inspiration for secular discourse. Part I of this thesis compares the significations of “interest” (Chapter 1), “riba” (Chapter 2), and “usury” (Chapter 3) as well as Islam’s prohibition of riba (Chapter 4) and Christianity’s prohibition of usury (Chapter 5). Since there is sufficient (though imperfect) overlap between these significations and prohibitions, Part II derives from rationales for the prohibitions of riba and usury lines of secular reasoning for analyzing the morality of interest. This analysis considers whether interest-based lending is immoral, presents moral risks, or its avoidance is supererogatory. This analysis takes into consideration the effects of interest-based lending (Chapter 6), considerations of virtue (Chapter 7), and the demands of justice (Chapter 8). Beyond its own subject matter, this case study exemplifies possibilities and challenges of attempting Islamo-Christian contributions to secular business ethics more widely.