Usul al-Fiqh

09

Tools the schools do not share equally

أدلة اختلفوا فيها

After the four sources, each school keeps extra keys. None of them is a second Quran. They are ways of reading when the four sources leave a space — or of choosing between two readings.

  1. عمل أهل المدينة

    Practice of Madinah

    Malik’s famous key. A widespread practice in the Prophet’s ﷺ city can outweigh a lone report. The other three do not give it that rank.

  2. الاستحسان

    Istihsan

    Hanafi (and some Maliki) preference: leaving a regular qiyas for a stronger dalil — a text, a need, or a hidden qiyas. Al-Shafii wrote against istihsan as a name. In practice his school does similar work under other names.

  3. المصلحة المرسلة

    Maslaha mursalah

    A public good the texts did not name and did not forbid. Malikis use it more. Collecting the mushaf, and Umar’s register, are the classical examples. It cannot make haram into halal.

  4. العرف

    Urf

    Custom that the Law did not reject. What counts as a meal in a dowry, what counts as a sale. Custom changes; the haram does not.

  5. سد الذرائع

    Sadd al-dharai

    Blocking the road to haram. Malikis and Hanbalis use it more. A permitted act is restricted if it usually leads to a sin.

  6. قول الصحابي

    A companion’s fatwa

    If a companion said it and none of them differed, it is close to ijma. If they differed, the mujtahid weighs. Ahmad gives the companion a high rank. Al-Shafii less so when a hadith is on the table.

  7. الاستصحاب

    Istishab

    Leaving what was as it was until a dalil moves it. The original of things is permissibility. Certainty is not lifted by doubt. This is why a person in wudu stays in wudu until he knows it broke.

Worked example

Why salah looks different

Hands at the sides (sadl) in famous Maliki practice is not because Malik ignored hadith. It is because he read those hadith against the amal of Madinah. Raf al-yadayn in Shafii and Hanbali practice is because they let those hadith speak. Same Sunnah, different usul keys. See Learn → Salah of the four schools.

Do not pick a tool because it gives you the answer you wanted. The school’s usul is a package. Hanafi istihsan without Hanafi hadith tests is not Hanafi.