The Four Sunni Sources
1. The Quran: The primary source — Allah’s direct word, eternally valid. Quranic commands are either qat’i (definitive — unambiguous texts) or zanni (indicative — texts open to interpretation). The jurisprudential challenge: the Quran contains approximately 500 verses directly relevant to legal matters — a rich but not exhaustive legal corpus.
2. The Sunnah: The Prophet’s practice (actions, sayings, and tacit approvals) — the second source, which elaborates, specifies, and sometimes abrogates Quranic rulings. The science of hadith authenticity (mustalah al-hadith) developed precisely to determine which Sunnah reports are reliable.
3. Ijma’ (Scholarly consensus): When the qualified scholars of a generation agree on a legal ruling, that consensus is binding on subsequent generations. The Ash’ari/Maturidi theological argument for ijma’: the Prophet: “My community will never agree on an error.”
4. Qiyas (Analogical reasoning): Extending a ruling from a Quranic/Sunnah case to a new case based on a shared effective cause (‘illa). Example: the Quran forbids wine (khamr) because it intoxicates → by qiyas, all intoxicants are forbidden, even those not mentioned in the Quran.
See also: Five Pillars Of Islam, Ahlussunnah, Aqida Islamic Creed, Sunnat Al Nabi
Additional Sources (Accepted Variably by Different Schools)
- Istihsan (Juristic preference): Hanafi and Maliki — choosing a ruling that serves the spirit of the Shariah better than strict qiyas
- Maslaha mursala (Unrestricted public interest): Maliki — extending law to serve the community’s genuine interest where no specific text applies
- ‘Urf (Custom): Custom that doesn’t contradict the Shariah may be legally relevant
- Sadd al-dhara’i’ (Blocking the means): Maliki — prohibiting permissible acts that lead to forbidden outcomes
See also: Qadi Al Numan, Jafar Al Sadiq, Imamah
The Ismaili Approach — Ta’lim over Ijma’
The Ismaili legal methodology represents a fundamental departure from the Sunni usul framework:
Ta’lim as the foundation: Where Sunni usul relies on scholarly consensus (ijma’) as a source of authority, Ismaili usul grounds itself in ta’lim — the authoritative teaching of the Imam. The living Imam’s interpretation of the Quran and Sunnah is not one voice among many scholarly voices; it is the binding interpretation that determines what the zahir requires and what the batin reveals.
The critique of qiyas: The Ismaili tradition (especially Nasir Khusraw and Hamid al-Din al-Kirmani) explicitly critiques the reliance on qiyas as a source of law. Human analogy, however careful, is inherently uncertain. Only the Imam — who carries the Prophet’s knowledge through nass — can extend law with certainty. Qiyas without the Imam’s validation is guesswork.
Qadi al-Nu’man’s Da’a’im al-Islam: The foundational Ismaili legal compendium — the Fatimid equivalent of a madhab — was written by Qadi al-Nu’man (d. 363 AH / 974 CE) on the authority of the Fatimid Imams. Its ruling on each issue traces directly to the Imam’s teaching, not to independent scholarly consensus.
See also: Tawil Esoteric Interpretation
See also: Five Pillars Of Islam, Ahlussunnah, Aqida Islamic Creed, Sunnat Al Nabi, Qadi Al Numan, Jafar Al Sadiq, Imamah, Tawil Esoteric Interpretation