|By the end of the 3rd century AH, in spite of the emphasis placed by an overwhelming number of fiqhi schools on the notion of independent thinking (ijtihad), an atmosphere of adhering to authority (taqlid: imitation) had come to dominate legal thinking. In fact, by this time, the thrust of a set of social and historical factors had given rise to the notion that instead of attempts at establishing new schools of thought faqihs should focus on the expansion and refinement of the existing methods. This meant that any attempt at ijtihad was to be carried out within the framework of the extant schools. The upshots of this development were the restriction of ijtihadi activity as well as the marginalization of many fiqhi schools which failed to gain recognition from the few well established schools of fiqh.
In any historical analysis of the rise of the notion of Four Fiqhi Schools (al-madhahib al-`arba`ah), and the like, it should be borne in mind that in the first three centuries of Islam one can only detect the traces of such ideas. In other words, in the 3rd century AH, Hanafism and Malikism were the two rival schools, with Shafi`ism being a late arrival. By the middle of the next century, the notion of the Four Schools was well known in the Islamic east, with the widely popular school of Dawud Isfahani as the fourth. The 5th century AH saw the appearance of the schools of Ahmad b. Hanbal and Sufyan Thawri. In some of the fiqhi works of the period, the schools of Dawud and Ahmad are placed alongside one another as the fourth school, both being second in rank to the first three. In fact, those who subscribed to the notion of al-madhahib al-`arba`ah would alternately refer to Dawud, Sufyan, or Ahmad as the leader of the fourth school. At the same time, in both extremes of the Islamic world there remained those who insisted on the sole legitimacy of the earlier three schools of fiqh.