Faqīh in the context of "Shafi'i"

Ibn Rushd (14 April 1126 – 11 December 1198), Latinized as Averroes, was an Andalusian polymath and jurist who was proficient in a variety of intellectual fields, including philosophy, theology, medicine, astronomy, physics, psychology, mathematics, neurology, Islamic jurisprudence and law, and linguistics. The author of more than 100 books and treatises, his philosophical works include numerous commentaries on Aristotle, for which he was known in the Western world as "The Commentator" and "Father of Rationalism".

Averroes was a strong proponent of Aristotelianism; he attempted to restore what he considered the original teachings of Aristotle and opposed the Neoplatonist tendencies of earlier Muslim thinkers, such as al-Farabi and Avicenna. He also defended the pursuit of philosophy against criticism by Ash'ari theologians such as Al-Ghazali. Averroes argued that philosophy was permissible in Islam and even compulsory among certain elites. He also argued scriptural text should be interpreted allegorically if it appeared to contradict conclusions reached by reason and philosophy. In Islamic jurisprudence, he wrote the Bidāyat al-Mujtahid on the differences between Islamic schools of law and the principles that caused their differences. In medicine, he proposed a new theory of stroke, described the signs and symptoms of Parkinson's disease for the first time, and might have been the first to identify the retina as the part of the eye responsible for sensing light. His medical book Al-Kulliyat fi al-Tibb, translated into Latin and known as the Colliget, became a textbook in Europe for centuries.

Fiqh ([fiːk]; Arabic: فقه [fiqh]) is the term for Islamic jurisprudence. Fiqh is often described as the style of human understanding, research and practices of the sharia; that is, human understanding of the divine Islamic law as revealed in the Quran and the sunnah (the teachings and practices of the Islamic prophet Muhammad and his companions). Fiqh expands and develops Shariah through interpretation (ijtihad) of the Quran and Sunnah by Islamic jurists (ulama) and is implemented by the rulings (fatwa) of jurists on questions presented to them. Thus, whereas sharia is considered immutable and infallible by Muslims, fiqh is considered fallible and changeable. Fiqh deals with the observance of rituals, morals and social legislation in Islam as well as economic and political system. In the modern era, there are four prominent schools (madh'hab) of fiqh within Sunni practice, plus two (or three) within Shi'a practice. A person trained in fiqh is known as a faqīh (pl.: fuqaha).

Figuratively, fiqh means knowledge about Islamic legal rulings from their sources. Deriving religious rulings from their sources requires the mujtahid (an individual who exercises ijtihad) to have a deep understanding in the different discussions of jurisprudence.

Ijtihad (/ˌɪdʒtəˈhɑːd/ IJ-tə-HAHD; Arabic: اجتهاد ijtihād [ʔidʒ.tihaːd], lit. 'physical effort' or 'mental effort') is an Islamic legal term referring to independent reasoning by an expert in Islamic law, or the thorough exertion of a jurist's mental faculty in finding a solution to a legal question. It is contrasted with taqlid (imitation, conformity to legal precedent). According to classical Sunni theory, ijtihad requires expertise in the Arabic language, theology, revealed texts, and principles of jurisprudence (usul al-fiqh), and is not employed where authentic and authoritative texts (Qur'an and hadith) are considered unambiguous with regard to the question, or where there is an existing scholarly consensus (ijma). Ijtihad is considered to be a religious duty for those qualified to perform it. An Islamic scholar who is qualified to perform ijtihad is called a "mujtahid".

For the first five centuries of Islam, the practice of ijtihad continued in theory and practice among Sunni Muslims. It then first became subject to dispute in the 12th century. By the 14th century, development of classic Islamic jurisprudence or fiqh prompted leading Sunni jurists to state that the main legal questions in Islam had been addressed, and to call for the scope of ijtihad to be restricted. In the modern era, this gave rise to a perception amongst Orientalist scholars and sections of the Muslim public that the so-called "gate of ijtihad" was closed at the start of the classical era. While recent scholarship established that the practice of Ijtihad had never ceased in Islamic history, the extent and mechanisms of legal change in the post-formative period remain a subject of debate. Differences amongst the Fuqaha (jurists) prevented Sunni Muslims from reaching any consensus (Ijma) on the issues of continuity of Ijtihad and existence of Mujtahids. Thus, Ijtihad remained a key aspect of Islamic jurisprudence throughout the centuries. Ijtihad was practiced throughout the Early modern period and claims for ijtihad and its superiority over taqlid were voiced unremittingly.

The Hanafi school or Hanafism is the largest school of Islamic jurisprudence out of the four principal schools within Sunni Islam. It developed from the teachings of the jurist and theologian Abu Hanifa (c. 699–767 CE), who systemised the use of reasoning (ra'y). Hanafi legal theory primarily derives law from the Quran, the sayings and practices of Muhammad (sunnah), scholarly consensus (ijma) and analogical reasoning (qiyas), but also considers juristic discretion (istihsan) and local customs (urf). It is distinctive in its greater usage of qiyas than other schools.

The school spread throughout the Muslim world under the patronage of various Islamic empires, including the Abbasids and Seljuks. The region of Transoxiana emerged as a centre of classical Hanafi scholarship between the 10th and 12th centuries, which gave rise to the Maturidi school of theology. The Ottoman Empire adopted Hanafism as its official school of law and influenced the legal thought of the school, eventually codifying it as the Mecelle in the 1870s.

Istislah (Arabic: استصلاح, lit. 'to deem proper') is a method employed by Islamic jurists to solve problems that find no clear answer in sacred religious texts. It is related to the term مصلحة Maslaha, or "public interest" (both words being derived from the same triconsonantal root, "ṣ-l-ḥ"). Extratextual pragmatic considerations are commonly accepted in Islamic jurisprudence concerning areas where the Qur'an and the practices of the earliest Muslim generations (Salaf) provide no specific guidance.

Istislah bears some similarities to the natural law tradition in the West, as exemplified by Thomas Aquinas. However, whereas natural law deems good that which is known self-evidently to be good, according as it tends towards the fulfilment of the person, istislah calls good whatever is connected to one of five "basic goods". Al-Ghazali abstracted these "basic goods" from the five legal precepts in the Qur'an and Sunnah—religion, life, reason, lineage (or offspring), and property. In this classical formulation, istislah differs from utilitarianism—"the greatest happiness for the greatest number of people"—because something that results in "the greatest happiness" may infringe any one of the five basic values. Rather than utilitarianism, Istislah bears closer resemblance to deontologicalism.

The Hanbali school or Hanbalism is one of the four major schools of Islamic jurisprudence, belonging to the Ahl al-Hadith tradition within Sunni Islam. It is named after and based on the teachings of the 9th-century scholar, jurist and traditionist, Ahmad ibn Hanbal (c. 780–855 CE), and later institutionalized by his students. One who subscribes to the Hanbali school is called a Hanbali (Arabic: ٱلْحَنْبَلِيّ, romanized: al-ḥanbalī, pl. ٱلْحَنْبَلِيَّة, al-ḥanbaliyya, or ٱلْحَنَابِلَة, al-ḥanābila). It mostly adheres to the Athari school of theology and is the smallest out of the four major Sunni schools, the others being the Hanafi, Maliki and Shafi'i schools.

Like the other Sunni schools, it primarily derives sharia from the Quran, hadith and views of Muhammad's companions. In cases where there is no clear answer in the sacred texts of Islam, the Hanbali school does not accept juristic discretion or customs of a community as sound bases to derive Islamic law on their own—methods that the Hanafi and Maliki schools accept. Hanbalis are the majority in Saudi Arabia and Qatar where the Salafi movement has grown. As such, Hanbalis form barely 5% of the Sunni Muslim population worldwide.

The Shafi'i school or Shafi'i Madhhab (Arabic: ٱلْمَذْهَب ٱلشَّافِعِيّ, romanized: al-madhhab al-shāfiʿī) or Shafi'i is one of the four major schools of Islamic jurisprudence, belonging to the Ahl al-Hadith tradition within Sunni Islam. It was founded by the Muslim scholar, jurist, and traditionist al-Shafi'i (c. 767–820 CE), "the father of Muslim jurisprudence", in the early 9th century.

The other three schools of Sunnī jurisprudence are Ḥanafī, Mālikī and Ḥanbalī. Like the other schools of fiqh, Shafiʽi recognize the First Four Caliphs as the Islamic prophet Muhammad's rightful successors and relies on the Qurʾān and the "sound" books of Ḥadīths as primary sources of law. The Shafi'i school affirms the authority of both divine law-giving (the Qurʾān and the Sunnah) and human speculation regarding the Law. Where passages of Qurʾān and/or the Ḥadīths are ambiguous, the school seeks guidance of Qiyās (analogical reasoning). The Ijmā' (consensus of scholars or of the community) was "accepted but not stressed". The school rejected the dependence on local traditions as the source of legal precedent and rebuffed the Ahl al-Ra'y (personal opinion) and the Istiḥsān (juristic discretion).

Ash'arism (/æʃəˈriː/; Arabic: ٱلْأَشْعَرِيّةُ, romanized: al-Ashʿarīyya) is a school of theology in Sunni Islam named after Abu al-Hasan al-Ash'ari, a Sunni jurist, reformer (mujaddid), and scholastic theologian, in the 9th–10th century. It established an orthodox guideline, based on scriptural authority, rationality, and theological rationalism. It is one of the three main schools alongside Maturidism and Atharism.

Al-Ash'ari established a middle way between the doctrines of the Atharī and Muʿtazila schools of Islamic theology, based both on reliance on the sacred scriptures of Islam and theological rationalism concerning the agency and attributes of God. Ashʿarism eventually became the predominant school of theological thought within Sunnī Islam, and is regarded as the single most important school of Islamic theology in the history of Islam.

A mufti (/ˈmʌfti/; Arabic: مفتي [muftiː], listen) is an Islamic jurist qualified to issue a nonbinding opinion (fatwa) on a point of Islamic law (sharia). The act of issuing fatwas is called iftāʾ. Muftis and their fatāwa have played an important role throughout Islamic history, taking on new roles in the modern era.

Tracing its origins to the Quran and early Islamic communities, the practice of ifta crystallized with the emergence of the traditional legal theory and schools of Islamic jurisprudence (madhahib). In the classical legal system, fatwas issued by muftis in response to private queries served to inform Muslim populations about Islam, advise courts on difficult points of Islamic law, and elaborate substantive law. In later times, muftis also issued public and political fatwas that took a stand on doctrinal controversies, legitimized government policies or articulated grievances of the population.