It is the science concerning the comprehensive evidences of fiqh.
It is the science concerning the comprehensive evidences of fiqh. Since fiqh consists of either [i] masaa‘il (issues) concerning which the ruling by one of the five rulings is sought, or [ii] it is the dalaa‘il (evidences) employed in extracting and determining these masaa‘il (issues).
So fiqh is actually knowledge of the masaa‘il (issues) and the dalaa‘il (evidences).
These dalaa‘il (evidences) are of two types:-
Comprehensive evidences that encompass every ruling - from the beginning to the end of fiqh - of a single kind; such as our saying: “al-amr lil-wujoob (a command is indicative of an obligation).” Or: “an-nahee lit-tahreem (a forbiddance is indicative of a prohibition).” And other similar evidences. So these are part of usoolul-fiqh.
Detailed evidences that are to be understood in the light of the comprehensive evidences. So when such is completed, then the ahkaam (rulings) can be resolved.
Thus, the ahkaam (rulings) are in need of their detailed evidences, and the detailed evidences are themselves in need of comprehensive evidences. So by this, we recognise the need and the necessity of knowing usoolul-fiqh, and that it aids in the understanding of fiqh itself, and that it is the foundations for deducing and making ijtihaad in the ahkaam (rulings).
The ahkaam (rulings) upon which fiqh revolve are five:-
Waajib (obligation): that for which the one who performs it is rewarded, whilst the one who abandons it is punished.
Haraam (prohibition): this is the opposite of an obligation.
Masnoon (recommended): that for which the one who performs it is rewarded, whilst the one who leaves it is not punished.
Makrooh (detested): this is the opposite of a recommendation.
Mubaah (permissible): this is where both (its doing or leaving) are equivalent.
Those rulings which are waajib (obligatory) are divided into two categories: fard ’ayn (individual obligation), the doing of which is sought from every mukallaf (morally responsible), baaligh (mature) ’aaqil (sane) person. The majority of the Sharee’ah rulings enter into this category. The second is fard kifaayah (collective obligation), the performance of which is sought from the morally responsible collectively, but not from every individual specifically; such as the learning of the various branches of useful knowledge and useful industries; the adhaan; the commanding of good and forbidding of evil; and other similar matters.
These five rulings differ widely in accordance with its state, its levels and its effects.
The adillah (evidences) that fiqh is derived from are four:-
The Book and the Sunnah, and these two are the foundation by which the mukallafoon (the morally responsible) are addressed, and upon which is built their Religion. Then ijmaa’ (consensus) and al-qiyaasus-saheeh (sound and correct analogy), these two are derived from the Book and the Sunnah. So fiqh - in its entirety - does not leave the realms of these four usool (fundamentals).
The majority of the important ahkaam(rulings) are indicated to by these four adillah (evidences). They are indicated to by the nusoos (texts) from the Book and the Sunnah; and the Scholars have ijmaa’ (consensus) about them, and they are indicated to by qiyaasus-saheeh (sound and correct analogy); because of what they entail of benefit, if it is a command; or what they contain of harm, if it is a forbiddance. Very few of the ahkaam have been differed over by the Scholars. In such cases the closest of them to the truth is the one who correctly refers back to these four usool.