36. Usul Al-fiqh
Linguistically ‘asl’ refers to that which is constructed upon, inclusive of both material construction, like the construction of walls upon a foundation, and rational construction, like the (analogical) construction of a ruling [ma’lūl] upon an effective cause [‘illah] or of a ruling [madlūl] upon an evidence [dalīl]. Thus usūl al-fiqh is the principles [qawā’id] upon which fiqh is built.
As for fiqh, linguistically it refers to understanding [fahm], as in the saying of Allah:
“We do not understand much of what you say…” [Hud: 91], and in the terminology of the legal scholars ‘fiqh’ is the knowledge of the practical shari’ah rules (which are) derived from the detailed evidences. The intent here of ‘knowledge of the rules’ with regards to the scholar [‘ālim] is not mere knowledge, rather it is the attainment of mastery of the shar’i ahkām, that is, that this knowledge and deep understanding of it reaches to the extent that it gives the person who knows these ahkām a mastery over them. Acquiring such a mastery suffices one to be considered a faqīh, even if he does not know all the ahkām. However it is necessary to know a collection of the branchial legal rulings through deliberation [nadhar] and deduction/evidencing [istidlāl]; knowing one or two rules is not called fiqh. Nor is knowledge of forming different types of evidences into proofs called fiqh. The word fiqh then is refers to the collection of the practical branchial rules, derived from the detailed evidences. Thus when it is said that ‘this is a book of fiqh’, it means that this book contains branchial practical rules; when fiqh is mentioned, the intent is a collection of practical branchial rulings. Importantly this is exclusive to the practical rules, because by the conventional definition, rules to do with belief [ahkām al-i’tiqādi] are not part of fiqh, because fiqh is particular to the branchial practical ahkām, that is, the rules which establish the actions, not beliefs.
Therefore the meaning of usūl al-fiqh is the principles [qawā’id] upon which the acquisition of the mastery of the practical rules (derived) from the detailed evidences is built. Hence usūl al-fiqh is defined conventionally as the knowledge of the principles whereby the derivation [istinbāt] of the shar’i rulings from the detailed evidences is attained; and these principles themselves are also termed usūl al-fiqh. A book of usūl al fiqh is a book which contains these principles. The study of usūl al-fiqh is a study of the principles and of the evidences, that is, of the ruling [hukm], the sources of the ruling, and the methodology of deriving the ruling from these sources. Usūl al-fiqh includes the general evidences [adillah ijmāliyyah] and the ways in which these indicate upon the shar’i rules, as it includes, generally, the state of the one doing the deduction [mustadil]; that is, (it includes) the knowledge of ijtihād. It also includes the methodology of derivation: weighing [ta’ādul] and giving preference [tarjīh] between evidences. Indeed, ijtihād and tarjīh depend upon knowledge of the evidences and the ways in which these indicate upon the rulings. Therefore the evidences and the way in which they indicate upon the rulings are the two foundations of usūl al-fiqh, together with the study of the ruling itself and matters related to it.
Thus usūl al-fiqh is the unspecified general indications for fiqh, like the absolute command [mutlaq al-‘amr], absolute prohibition [mutlaq al-nahy], the action of the Prophet (saw), ijma’ al-sahaba and qiyas. This excludes the detailed specific indications like “Establish prayer”, “And do not come near fornication”, the prayer of the Messenger (saw) inside the Ka’bah, the establishment of guardianship [wilāyah] over the one incapable of looking after his own affairs [mahjūr], the deserving of the representative to wages when hired on the basis of payment on analogy to an employee. All these are not part of usūl al-fiqh because they are specific detailed evidences. Finding them used as examples in the study of usūl al-fiqh does not mean they are a part of it. Nay, usūl al fiqh is the general evidences, the way in which these indicate (upon the ruling), the state of the one evidencing, and the methodology of evidencing [istidlāl].
Usūl al-fiqh differs from fiqh in that the subject of fiqh is the actions of the servants with regards to them being permissible, prohibited, valid, invalid and void. As for usūl al fiqh, its subject is the textual evidences with regards to the shar’i ahkām being derived from them, that is, with regards to how they establish the shar’i ahkām. Thus it is necessary (in studying usūl al-fiqh) to study the hukm and that which is related to it with regards to the explanation of who is it that issues the hukm, that is, who has the right to issue the hukm: who is the legislator, and with regards to upon whom does the hukm apply, that is, who is responsible for executing the hukm, meaning, the one upon whom the hukm is obligated [mahkūm ‘alayh], and with regards to the hukm itself: what is it, and what is its reality? After this comes the explanation of the evidences and the ways in which they indicate upon the ruling