Different regions within the Islamic empire developed divergent regional legal traditions, which were reproduced in study circles, or ḥalqah (so named because the teacher was, as a rule, seated on a dais or cushion with the pupils gathered in a semicircle before him). The most active study circles were found in the Hejaz (a region on the west coast of the Arabian Peninsula) and Iraq, although those in Syria and Egypt also played a role. With the emergence of written legal culture, the regional traditions faced a need to justify their doctrines in a systematic way and to engage with traditions from other regions. Encased in books, the doctrines of the regional schools became mobile and could be spread beyond their original locations. As a result, the locus of school identity shifted from places to the individuals responsible for their elaboration and codification. In particular, the school of Medina became associated with Mālik ibn Anas (died 795), Medina’s most prominent jurist in the late 8th century, and came to be known as the Mālikī school, and the school of Kūfah turned into the Ḥanafī school, named after its greatest jurist, Mālik’s contemporary Abū Ḥanīfah (died 767).

These legal schools with regional roots had to contend with another 8th-century development: the systematic collection of reports concerning the sayings and actions attributed to the Prophet Muhammad (Hadith). The regional schools had already made use of such traditions, but their wide-scale collection and dissemination meant that the schools were confronted with hitherto unknown prophetic traditions that contradicted their established positions. Generally speaking, the Mālikīs and the Ḥanafīs gave greater weight to their regional traditions in resolving this tension, whereas two school-founding jurists of the subsequent generation, Muḥammad ibn Idrīs al-Shāfiʿī (died 820) and Aḥmad ibn Ḥanbal (died 855), sought to transcend localism by granting priority to authentic traditions. Ibn Ḥanbal drew on both prophetic traditions and the opinions of early Muslim jurists throughout Muslim lands. Al-Shāfiʿī, by contrast, rejected the putative precedential authority of regional legal traditions and of the early jurists in general. Instead, he proposed a system in which the Qurʾān and the Prophetic example (Sunnah) were the only authoritative sources of law and then developed a toolkit of methods for systematically deriving legal rules from the sources and extending these rules to areas not directly covered by the sacred texts. A prominent element of this toolkit was analogical reasoning (qiyās).

Al-Shāfiʿī’s insistence on the importance of the Sunnah as a source of law prompted great activity in the collection and classification of Hadith reports, particularly among his own supporters, who formed the Shāfiʿī school, and the followers of Ibn Ḥanbal, who formed the Ḥanbalī school. Muslim scholarship maintained that the classical compilations of Hadith—especially those of al-Bukhārī (died 870) and Muslim (died 875)—constituted an authentic record of the Prophet’s precedents. However, Western Orientalists have traditionally been skeptical of the attribution of most alleged Prophetic hadiths, arguing that they represent the views of later scholars fictitiously ascribed to the Prophet to give doctrines greater authority.

Later developments

Al-Shāfiʿī’s thesis formed the basis of the classical theory of the roots of jurisprudence (uṣūl al-fiqh), which crystallized in the early 10th century. Juristic “effort” to comprehend the terms of the sharia is known as ijtihād, and legal theory charts the course that ijtihād must follow. In seeking the answer to a legal problem, the jurist must first consult the Qurʾān and Hadith. If no specific solution can be discovered in divine revelation, the jurist must employ analogy (qiyās) or certain subsidiary principles of reasoning, such as istiḥsān (juristic discretion) and istiṣlāh (consideration of welfare). As an attempt to define God’s law, the ijtihād of individual scholars can result only in a tentative conclusion, termed ẓann (“conjecture”), which is contrasted with the ideal of certain (yaqīn) knowledge.

Sharia law is a candidly pluralistic system, the philosophy of the equal authority of the different schools being expressed in a putative dictum of the Prophet: “Difference of opinion among my community is a sign of God’s bounty.” Outside the four schools of Sunni Islam stand the minority groups of the Shiʿah and the Ibāḍīs, whose versions of the sharia differ considerably from those of the Sunnis. Shiʿi law, in particular, grew out of a fundamentally different politico-religious system, in which the rulers, or imams, were held to be divinely inspired and therefore the spokesmen of the Lawgiver himself. Geographically, the division between the various schools and sects became fairly well defined as qadis’ courts in different areas became wedded to the doctrine of one particular school. Thus, Ḥanafī law came to predominate in the Middle East and the Indian subcontinent; Mālikī law in North, West, and Central Africa; Shāfiʿī law in East Africa, the southern parts of the Arabian Peninsula, Malaysia, and Indonesia; Ḥanbalī law in Saudi Arabia; Shiʿi law in Iran and the Shiʿi communities of India and East Africa; and Ibāḍī law in Zanzibar, Oman, and parts of Algeria.

Although sharia doctrine is all-embracing, Islamic legal practice has always recognized jurisdictions other than that of the qadis. Because the qadis’ courts were hidebound by a cumbersome system of procedure and evidence, they did not prove a satisfactory organ for the administration of justice in all respects, particularly as regards criminal, land, and commercial law. Hence, under the broad heading of the sovereign’s administrative power (siyāsah), competence in these spheres was often relegated to other courts, known collectively as maẓālim courts, and the qadis’ monopoly was confined to private family and civil law. As the expression of a religious ideal, sharia doctrine was always the focal point of legal activity, but it never formed a complete or exclusively authoritative expression of the laws that governed the lives of Muslims in practice.