<論考>イスラーム成立期における社会・経済変容とリバー禁止の史的展開

Abstract

Because of the well-known Islamic prohibition of "ribā", or interest, an effort to (re)establish Islamic economies was initiated by starting Islamic banks as "interest-free banking" in the 1970's. During their development in the following decades, the proposal to define all forms of interest as prohibited ribā was firmly established and widely accepted. The prohibition of ribā is clearly stated in the Qur'an, the sacred book of Islam and the first source of Islamic law. All legal schools have maintained the prohibition of ribā. On the other hand, ribā was not prohibited at once during the Prophetic period (610–632 C.E.), during which the contents of the Qur'an were gradually revealed. In order to understand why and how the ribā was prohibited, this article reconstructs the historical developments of the prohibition of ribā during the Prophetic period, considering the four periods during which the four sets of Qur'anic verses relating to ribā were revealed, by utilizing Asbāb al-Nuzūl, or Occasions of the Revelation, in the literatures of the Qur'anic exegesis (tafsīr). Occasions of the Revelation are reference to when, why and how each set of verses, or legal sanctions contained in those verses, were given to Muhammad and his followers, so they are useful to determine the circumstances and contexts of each legal sanction. While in the first period in Makka when Muslims didn't have any control over the Makkan economy, ribā transactions were just criticized. In the second period in Madina, the Jewish practice to charge ribā on Muslims were strongly criticized. As the Islamic community and Muslims spread and new sources of income appeared, zakāt and loans without interest were emphasized as good deeds and ribā was partially prohibited. In the fourth and final period, ribā was totally prohibited, and more constructive investments were strongly urged. This article thus demonstrates the necessity and benefit of understanding the original circumstances and contexts of the Qur'anic ordinances in the economic domain, so that we may have a better understanding of the true nature of Islamic economy which the current Islamic economics aims to develop within the contemporary economic conditions.