This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
The eight schools recorded here were not canonized all at once, and treating their formation as a single, simultaneous event flattens a documented history that took centuries. The four schools historically classed as Sunni, Hanafi, Maliki, Shafii and Hanbali, coalesced gradually out of the ninth and tenth century's competing local approaches to deriving law from the Quran, the hadith, communal consensus and analogical reasoning, a slow narrowing to a small number of schools whose methods were eventually recognized as authoritative alongside one another rather than in competition to eliminate the rest. The Twelver Shia Jafari school, the Zaidi school and the Ibadi school, whose own origin predates the later hardening of the Sunni and Shia division, followed their own separate and equally documented paths to their present form, and the largely historical Zahiri school pursued a distinct method of strict textual literalism that most of the others explicitly argued against.
Studying these schools comparatively means tracing each one's own documented method for weighing the recognized sources of law against the others, since the schools differ genuinely in method, in how much weight is given to analogy, to regional custom, to a jurist's own reasoning, and not merely in the conclusions any one of them reaches on a given question. A structural fact worth stating plainly across every school: Sunni Islam in particular has no ordained clergy and no central institution comparable to a church, so a school's standing rests on its accumulated body of legal reasoning and on the jurists trained in its method, not on any office empowered to declare doctrine for the whole tradition.
A school's documented method, rather than any single verdict it has produced, is therefore what the comparative study of these schools actually studies, which is why an entry on any one of the eight schools records the method and its history before it records any particular ruling.