Şer’î hüküm denildiğinde, insanların gerek bireysel yapıp etmelerine gerekse başkalarıyla olan ilişkilerine dair değer yargılarından söz edilmiş olur. Bireysel açıdan bir şeyin yapılmasının, farz, vacip, sünnet, mübah, mekruh ve haram oluşu; hukuki açıdan ise bir hukuki işlemin sahih, batıl veya nafiz oluşu yapıp etmelerimize dair hükümlerdir. Hükmün tanımı ve mahiyeti meselesi özellikle Mutezile ve Ehl-i Sünnet arasında Allah’ın sıfatları, özellikle kelam sıfatı ve buna bağlı olarak Kur’an’ın mahlûk olup olmadığı konusunda adeta kozlarını paylaştıkları bir tartışma alanı olmuştur. Şer’î hükmü tanımlarken usulcüler doğal olarak Şâri’in hitabını merkeze koymuşlar; ancak bazı kelamî kabullerin sonucu olarak hükmün tanımı konusunda aralarında kimi farklılıklar ortaya çıkmıştır. Hükmün tanım ve mahiyetine yansıyan kelami tartışmalardan biri Allah’ın kelamının kadîm olup olmadığı, bir diğeri ise aklın değer yargısı belirlemede bir rolünün bulunup bulunmadığıdır. Hükmün tanımı konusunda usulcüler arasında genel olarak belli başlı iki yaklaşımın bulunduğu söylenebilir. Bunlardan birincisi Mutezile ve Eş’arîlerin oluşturduğu kelamcı usulcülere ait olup, hükmü hitabın kendisi olarak tanımlayan yaklaşımdır. Hükmün tanımı konusundaki ikinci yaklaşım ise Hanefi usulcülere aittir. Bu yaklaşıma göre hüküm, hitabın kendisi değil sonucudur. Birinci yaklaşıma göre hüküm, “Şâri’in mükellefin fiillerine iktiza veya tahyir cihetiyle taalluk eden hitabı”dır. Mutezilenin hüküm tanımı da zahiren aşağı yukarı böyledir. Ama onlar genel olarak aklı da hüküm koyucu olarak görmeleri ve akıl yoluyla ulaşılan hükümleri de şer’î hüküm kapsamında görmeleri yönüyle Eş’arî usulcülerden ayrıldıkları gibi, hitabı ve hükmü “yaratılmış” (hâdis) görmeleri yönüyle de onlardan ayrılırlar.

Although usul al-fiqh (the methodology of Islamic jurisprudence) is described only as evidence (dalil) especially by the mutakallim scholars of usul al-fiqh, at this point, the evidence is important in pointing to judgments (ahkam, sg. hukm). Therefore, although there are different approaches about the essentialness and priority, hukm is the basic subject of usul al-fiqh. For this reason, Molla Khusrev (d. 885 / 1480) described usul al-fiqh as a science which is used to know the situations of adilla (evidences) and ahkam (judgments) by explicitly mentioning both. Gazzâlî (d. 505 / 1111) also began his book of usul al-fiqh with the subject of hukm he explained with the semere (fruits of the tree) metaphor.Al-hukm al-shar’i (legal) is the judgment about people’s individual acts or their relations with others. From the individual point, hukm is related to the fact that an act has been fard (obligatory), wajib (necessary), sunnah (recommended), mubah (permissible), makruh (disapproved), haram (forbidden); from the legal point of view, it is related to the fact that a legal transaction has been sahih (valid), fasit (voidable), or batıl (void).The question of the definition and nature of the hukm was a discussion area about especially God's attributes and whether Quran was created or not between Mu’tazila and Ahl al-Sunnah. While defining al-hukm al-shar’i, usul al-fiqh scholars placed naturally the hitab (a speech or communication from the Shari) to the center. However, as a consequence of some Kalamic assumptions, some differences have emerged between them in the definition of the hukm. One of the arguments reflected in the definition and nature of the hukm is whether the word (kalam) of God is ancient, and the other is the function of the reason (al-akl) in judgement.There are generally two main approaches to the definition of the hukm between the scholars of usul al-fikh. The first one belongs to the mutakallimun, which is composed of the scholars of Mu’tazila and Ash’ari and is the approach that defines the hukm as the hıtab itself. The second approach to the definition of the hukm belongs to the Hanafi scholars. According to this approach, the hukm is the effect/result of the hıtab, not the hıtab itself.According to the first one, al-hukm is the hıtab of Shari about to the acts of men, which consists a demand to do something or not, or an option about both. The definition ot Mu’tazila is approximately the same. However, they differ from Ash’ari in terms of accepting the reason as the judge and seeing the ahkam reached by the reason as al-hukm al-shar’i. They also separate from them in terms of seeing kalamullah as created.According to them, the ahkam that Shari does not intervene are also included in the scope of the framework hukm. Generally speaking, according to the Mutazila, al-hukm al-shar’i is any hukm in which it is necessary to recourse to Sharia. At this point, there is a basic difference between the Sunni scholars and the Mu’tazilite scholars about the function of reason in judgement.The definition of the hukm which is relatively preferred by Hanafi scholars (fuqaha) is the effect/result of the hıtab of Shari. Some of the mutakallim scholars also adopted this definition with the idea that it allows them to avoid some of the criticisms of Mu’tazila. In fact, Najm al-Din al-Tûfî (d. 716 / 1316), who wrote in the tradition of the mutakallim method, states that if the hukm is defined not as the hıtab itself but its requirement (muktada), Mu’tazila could not object to justification of ancient hıtab with non-ancient cause. Usul al-fiqh scholars’ definitions of al-Hukm al-shar’i and the discussions on these definitions have been discussed in connection with theological (kalami) problems especially in the works of mutakallim scholars of usul al-fiqh (the methodology of Islamic jurisprudence). Since the definition of the concept al-hukm has been made in the context of a legal system in which Muslims have politically dominated throughout the history, scholars of usul al-fiqh did not need to draw attention to these external conditions for the existence of the al-hukm. From the beginning to these days, this situation gave the impression that al-hitab was perceived as a direct sharia judgement itself without any additional condition. In the modern period, the classical definition of the al-hukm was preserved as if there was no change in the historical process, the Muslim community was still dominating as a political and social power, and it was still in the dar al-Islam (places ruled by Islam).