Sunni Muslims affirm the authority of the four surviving schools (madhhabs) of jurisprudence (Hanafi, Maliki, Shafii, and Hanbali), as legitimate methods for deriving law from the Quran and the Sunna. Each traces to an early jurist and to a distinctive weighting of the sources of law: text, prophetic precedent, consensus (ijma), and analogy (qiyas), with some schools admitting further tools such as juristic preference or the practice of Medina. A Sunni ordinarily follows one school while regarding the others as equally within the bounds of orthodoxy.
The four schools take their names from jurists of the eighth and ninth centuries: Abu Hanifa (died 767), Malik ibn Anas (died 795), Muhammad al-Shafii (died 820), and Ahmad ibn Hanbal (died 855), each of whose students and successors elaborated a distinct legal methodology from his teaching. They are the survivors of a wider field of early schools; the literalist Zahiri school, associated with Dawud al-Zahiri and later systematised by Ibn Hazm, and regional schools such as the Awzai in Syria and the Thawri, once had significant followings but did not sustain the institutional continuity, textbooks, and state patronage that allowed the four to become and remain the recognised Sunni mainstream.