Honor (karâma) in individuals, congregation (jamâ’a) in public life and legal capacity and credibility in administration are considered basic to Islam. Both men and organizations must be reformed in order to reconcile individual felicity and public interest toward a more perfect society. Religious beliefs and performances provide the most convenient ground for orientating natural drives, propensities and habits in a positive direction and for maintaining and promoting norms and virtues such as trust, honesty, cooperation, etc., which are indispensible for Islamic as well as open, pluralistic and liberal societies. This article studies Yahyâ ibn ‘Umar al-Kinânî’s work entitled Kitâb Ahkâm al-sûk with regard to the fact that it is known as the oldest available example of the genre emphasizing the above norms and virtues. For, some sections thereof, dedicated to economic transactions, introduce an applied value system, which offers a proper ground for taking correct business decisions, and also bestow ethical norms, which render possible the classification and evaluation of business and marketing behaviours. This paper subjects al-Kinânî’s opinions to a legal, economic and ethical analysis from an interdisciplinary perspective in order not to fall into the trap of either reductionism or methodological monism.