Tradition and Ijtihād in Christianity and Islam: Mechanisms Employed to Meet the Social Needs

The scope of religion and its role against the social transformations is an important subject to deal with. In this article we try to answer this question: Have Islam and Christianity been able to, on the one hand, follow their doctrines and on the other hand meet the changing needs of society? In fact, Christianity by removing the Jewish law and emphasizing on the fluid tradition based on its believers' understanding has succeeded in adapting to the new conditions. Shi'ite Islam by using the 250 hundred years traditions of its Imams has developed some flexible elements in itself. In Sunni Islam, qiyās (deductive analogy), somehow played the same role but the lack of ijtihād and the exclusive dominance of the four jurisprudential schools have erected strong barriers in its way.