Fiqh (Islamic Jurisprudence)

Ijtihad - novel jurisprudential enterprise the consists of creating new rulings in Islam law or altering the methodology through which those rulings are arrived at.

Mujtahid - a scholar of Islamic jurisprudence considered sufficiently competent in the field to be able to engage in ijtihad.

Ahkam

There are, generally, "five rulings" (الأحكام الخمسة, or al-aḥkām al-khamsa) that any action can be categorized under according to the theory of Fiqh:

Fard (or wajib) - actions which are obligatory

Mustahab (or mandub) - actions which are preferred and advisable

Mubah - actions which are neutral in the eyes of God and which incur no judgement from him

Makruh - actions which are disliked and reprehensible, but are not considered sins (avoiding them, however, is supposed to earn one "good deeds")

Haram (or mahzur) - actions which are forbidden absolutely and which incur sin

The development of Fiqh consists of the following important phases^[2]:

1. Muhammad's life time (571-632), during which rulings come directly from Muhammad and Allah
2. Following Muhammad's death, until about 670, Muhammad's companions, or sahaba issue "personal interpretations" and rulings regarding Islamic law
3. Between 670 and the early 8th century, competing scripture-based ("traditionalist") and "rationalist" interpretive tendencies emerge in the Hijaz (western Arabia) and Kufa, Iraq, respectively.
4. Between the 8th and 10th centuries, formal schools of law emerge, including those of the four Sunni and major Shi'ite jurists. This is referred to as the "golden age of classical Islamic jurisprudence". Novel jurisprudential thought is mostly limited to this period, and "rationalist" tendencies are mostly suppressed, but end up maintaining a limited degree of expression in the schools of Imam Abu Hanifa and Imam Malik (though even their schools are best characterized, hereafter, as "traditionalist").
5. Between the 10th and 13th centuries, the existing major schools of law are elaborated and systematized in great detail, though no new major systems of law are introduced. At the end of this period, it is famously said that the "doors of ijtihad were closed".
6. Between the 13th and 19th centuries, the "doors of ijtihad" remain closed. This is the so-called "dark age" of Islamic jurisprudence. In the 19th century, Muhammad ibn Abdul-Wahhab, building on Ibn Hanbal's ideas, gives start to what will become the Salafi movement, seeking to overturn the complicated methodologies of the four Sunni schools of law in favor of a more literal and direct reading of scripture - preferring direct reference to a hadith in lieu of a more complex fatwa.
7. Between the 19th and 21st centuries, the Salafi movement grows and fractures into various strains, one of which gives rise to radical Islamism, though never grows larger than the four traditional schools of Islamic law. Modernizers emerge, such as Muhammad Abduh, Abd al-Razzak al-Sanhuri, and Tariq Ramadan, among others. These modernizers place less emphasis on literal readings of scripture and more emphasis on the broad themes and purposes of the Shari'ah (maqasid al-Shari'ah). The modernist movement, even less impactful than the Salafi movement, however, fails to overwhelm or substantially redirect the "traditionalist" mainstream.

Daleel

The jurisprudential methodology (Usul al-Fiqh, lit. "the Principles of Jurisprudence") developed by the schools of Islamic law comprise of a hierarchy of various proofs, or adillah (sing. daleel). Though this hierarchy differs for every school of Islamic law, the all generally agree that the Qur'an, hadith, ijma (scholarly concensus), and some form of qiyas (analogy) are, in that order, among the first five daleels.

• Reliance of the Traveller (Revised Edition) - 30.2 MB PDF file

• Reliance of the Traveller: The Classic Manual of Islamic Sacred Law Umdat Al-Salik - Online text of a book of Shafi'i Fiqh
• The Risala of 'Abdullah ibn Abi Zayd al-Qayrawani (310/922 - 386/996) - A Treatise on Maliki Fiqh