Islamic theology (kalām) and philosophy (falsafah) are two traditions of learning developed by Muslim thinkers who were engaged, on the one hand, in the rational clarification and defense of the principles of the Islamic religion (mutakallimūn) and, on the other, in the pursuit of the ancient (Greek and Hellenistic, or Greco-Roman) sciences (falāsifah). These thinkers took a position that was intermediate between the traditionalists, who remained attached to the literal expressions of the primary sources of Islamic doctrines (the Qurʾān, Islamic scripture; and the Hadith, sayings and traditions of the Prophet Muhammad) and who abhorred reasoning, and those whose reasoning led them to abandon the Islamic community (the ummah) altogether. The status of the believer in Islam remained in practice a juridical question, not a matter for theologians or philosophers to decide. Except in regard to the fundamental questions of the existence of God, Islamic revelation, and future reward and punishment, the juridical conditions for declaring someone an unbeliever or beyond the pale of Islam were so demanding as to make it almost impossible to make a valid declaration of this sort about a professing Muslim. In the course of events in Islamic history, representatives of certain theological movements, who happened to be jurists and who succeeded in converting rulers to their cause, made those rulers declare in favour of their movements and even encouraged them to persecute their opponents. Thus there arose in some localities and periods a semblance of an official, or orthodox, doctrine.
