Ijtihad in the context of "Istihsan"

Early Islamic philosophy or classical Islamic philosophy is a period of intense philosophical development beginning in the 2nd century AH of the Islamic calendar (early 9th century CE) and lasting until the 6th century AH (late 12th century CE). The period is known as the Islamic Golden Age, and the achievements of this period had a crucial influence in the development of modern philosophy and science. For Renaissance Europe, "Muslim maritime, agricultural, and technological innovations, as well as much East Asian technology via the Muslim world, made their way to western Europe in one of the largest technology transfers in world history." This period starts with al-Kindi in the 9th century and ends with Averroes (Ibn Rushd) at the end of 12th century. The death of Averroes effectively marks the end of a particular discipline of Islamic philosophy usually called the Peripatetic Arabic School, and philosophical activity declined significantly in Western Islamic countries, namely in Islamic Spain and North Africa, though it persisted for much longer in the Eastern countries, in particular Persia and India where several schools of philosophy continued to flourish: Avicennism, Illuminationist philosophy, Mystical philosophy, and Transcendent theosophy.

Intellectual innovations, achievements, and advancements of this period included, within jurisprudence, the development of ijtihad, a method or methodological approach to legal reasoning, interpretation, and argument based on independent inquiry and analogical deduction; within science and the philosophy of science, the development of empirical research methods emphasizing controlled experimentation, observational evidence, and reproducibility, as well as early formulations of empiricist epistemologies; commentaries and developments in Aristotelian logic, as well as innovations in non-Aristotelian temporal modal logic and inductive logic; and developments in research practice and methodology, including, within medicine, the first documented peer review process and within jurisprudence and theology, a strict science of citation, the isnad or "backing".

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.

The Jaʿfarī school, also known as the Jafarite school, Jaʿfarī fiqh (Arabic: الفقه الجعفري) or Ja'fari jurisprudence, is a prominent school of jurisprudence (fiqh) within Twelver and Ismaili (including Nizari) Shia Islam, named after the sixth Imam, Ja'far al-Sadiq. In Iran, Jaʽfari jurisprudence is enshrined in the constitution, shaping various aspects of governance, legislation, and judiciary in the country. In Lebanon, this school of jurispudence is also accounted for in the legal system of the country and Shia Muslims can call upon it for their legal disputes.

It differs from the predominant madhhabs of Sunni jurisprudence in its reliance on ijtihad, as well as on matters of inheritance, religious taxes, commerce, personal status, and the allowing of temporary marriage or mutʿa. Since 1959, Jaʿfari jurisprudence has been afforded the status of "fifth school" along with the four Sunni schools by Azhar University. In addition, it is one of the eight recognized madhhabs listed in the Amman Message of 2004 by King Abdullah II of Jordan, and since endorsed by Sadiq al-Mahdi, former Prime Minister of Sudan.

Principles of Islamic jurisprudence (Arabic: أصول الفقه, romanized: ʾUṣūl al-Fiqh) are traditional methodological principles used in Islamic jurisprudence (fiqh) for deriving the rulings of Islamic law (sharia).

Traditional theory of Islamic jurisprudence elaborates how the scriptures (Quran and hadith) should be interpreted from the standpoint of linguistics and rhetoric. It also comprises methods for establishing authenticity of hadith and for determining when the legal force of a scriptural passage is abrogated by a passage revealed at a later date. In addition to the Quran and hadith, the classical theory of Sunni jurisprudence recognizes secondary sources of law: juristic consensus (ijmaʿ) and analogical reasoning (qiyas). It therefore studies the application and limits of analogy, as well as the value and limits of consensus, along with other methodological principles, some of which are accepted by only certain legal schools (madhahib). This interpretive apparatus is brought together under the rubric of ijtihad, which refers to a jurist's exertion in an attempt to arrive at a ruling on a particular question. The theory of Twelver Shia jurisprudence parallels that of Sunni schools with some differences, such as recognition of reason (ʿaql) as a source of law in place of qiyās and extension of the notions of hadith and sunnah to include traditions of the imams.

Taqlid (Arabic: تقليد, romanized: Taqlīd) is a term used in Islamic jurisprudence to denote the conformity of one person to the teaching of another. As such, the person who performs taqlid is termed muqallid. The definite meaning of the term varies depending on context and age. Classical usage of the term differs between Sunni Islam and Shia Islam. Sunni Islamic usage designates the unjustified conformity of one person to the teaching of another, rather than the justified conformity of a layperson to the teaching of a mujtahid (a person who is qualified for independent reasoning). Shia Islamic usage designates general conformity to the teaching of a mujtahid, and there is no negative connotation. The discrepancy corresponds to differing views on the Shia Imamate and Sunni imams.

In contemporary Salafi usage, taqlid is often portrayed in a negative light and translated as "blind imitation". This refers to the perceived stagnation of independent effort (ijtihad) and uncritical imitation of traditional religious interpretation by the religious establishment in general.

Nizari Isma'ilis (Arabic: النزارية, romanized: al-Nizāriyya) are the largest segment of the Ismailis, who are the second-largest branch of Shia Islam after the Twelvers. Nizari teachings emphasise the independent legal jurisprudence or ijtihad—though they reject legal reasoning, or usul—pluralism (the acceptance of racial, ethnic, cultural and inter-religious differences) and social justice. Nizaris, along with Twelvers, adhere to the Jaʽfari school of jurisprudence. The Aga Khan, currently Aga Khan V, is the spiritual leader and Imam of the Nizaris. The global seat of the Ismaili Imamate is in Lisbon, Portugal.