To say usul al fiqh is one of the most challenging sciences will not be an overstatement. Those who become proficient in this science undoubtedly become an inch closer to the lofty status of a mujtahid.
Usul al-fiqh concentrates on the procedures by which legal rules may be deduced from the source materials of the Shari’ah. The sources of shari’ah are of two kinds: revealed and non-revealed. Whereas the former provide the basic evidence and indications from which detailed rules may be derived, the latter provide the methodology and procedural guidelines to ensure correct utilisation of the source of evidence.
The words Usul al fiqh are composed of two words: Usul and fiqh. Usul is the plaural of asl, which is commonly translated as foundation, root or origin. Fiqh is translated as jurisprudence. Hence, Usul al fiqh will be translated as the ‘foundations of fiqh’ or ‘the origins of fiqh’.
Have you ever wondered where the rulings of contemporary issues come from? Rulings regarding prayers on an aeroplane, plastic surgery, organ transplants, usage of credit cards aren’t explicitly mentioned in the sacred texts, yet the Jurists will answer your queries regarding such issues in light of the sacred texts. The answer unanimously is: Usul al fiqh.
Usul al-fiqh, or the origins of fiqh, thus expound the indications and methodology by which rules of fiqh are deduced from their source of evidence. The rules of fiqh are thereby derived from the Quran and Sunnah in conformity with a body of principles and methods which are collectively known as usul al-fiqh.
To deduce the rules of fiqh from the indications that are provided in the sources is the expressed purpose of usul al-fiqh.
To say that usul al-fiqh is the science of studying the sources as well as the methodology of the law is accurate. The Quran and Sunnah constitute the sources as well as the subject matter, to which the methodology of usul al-fiqh is applied.
The methodologies to deduce rulings:
1) Ijmaa’ (Consensus of opinion)
2) Qiyaas (Analogical deduction)
3) Istihsaan (Juristic preference)
4) Al-masaalih al-mursalah (considerations of public interest)
5) ‘Urf (custom)
6) Shar’u man qablanaa (revealed laws preceding the shari’ah of Islam)
7) Mathhab as-sahabi (fatwa of a companion)
8) Al-istishaab (Presumption of continuity)
9) Ath-tharaa’i (Blocking the means)