Islamic Law, commonly referred to as Shariah, governs interpersonal conduct and regulates the ritual practices of Muslims. In some countries it is also the governing law, while other countries apply Islamic law to specific areas, such as personal status or finance.  

There are two primary sects of Islam, Sunni and Shi’i. Sunnis account for about 90 percent of Muslims worldwide, Shi’i about 10 percent. The split between the two sects followed a disagreement over the leadership of the Muslim community (ummah) when the Prophet Muhammad died in 632 CE. 



Islamic law is derived primarily from two textual sources: the Qur’an, the holy book of Islam, and the Sunnah, the sayings and conduct of the Prophet Muhammad.

Quran with geometric pattern

The Qur’an is believed to be the word of God, as revealed to the Prophet through Archangel Gabriel over twenty-three years in seventh-century Arabia. When faced with a legal question, scholars (ulama) first look to the Qur’an However, this sacred text is shorter than the New Testament and not primarily legal; only about 10 percent is devoted to precise commands. 


If unable to resolve a legal question with reference to the Qur’an, scholars turn to the Sunnah. The Sunnah consists of hadith or verbal narratives about the Prophet. After the death of the Prophet, hadith were compiled, organized around authenticity and subject matter, and recorded. Sunni and Shi’ia disagree over which hadith are valid. 

Sunnah with geometric pattern

When an answer to a legal query cannot be found in either the Qur’an or Sunnah, scholars rely upon two secondary doctrines: qiyas and ijma.

Qiyas with geometric pattern

Qiyas (literally, “measuring” or “ascertaining” the length, weight, or quality of something) is reasoning by analogy. The doctrine of qiyas is based on the idea that God had reasons for commanding or forbidding a particular activity in the Qur’an. The doctrine of qiyas tests whether an injunction or position held within the Qur’an or Sunnah can be extended from its original case to a new set of facts.  


Ijma is invoking the Prophet’s declaration that “[m]y community [of believers] will never agree on an error,” legal scholars established the doctrine of consensus known as ijma. Although an individual scholar’s opinion may not be deemed dispositive, if consensus is reached about a particular matter, it is regarded as conclusive and binding law. The legal authority of ijma is second only to the Qur’an and the Sunnah.  

Ijma with geometric pattern

Schools of Jurisprudence

In the first hundred years after the Prophet’s death, legal doctrines and schools of jurisprudential thought, madhab, began to form around a particular legal paradigm. The schools of jurisprudence, originally numerous, merged over time. There are four primary Sunni schools: Hanafi, Shafi’i, Maliki, and Hanbali. Jafari is the predominant Shi’i school. 


  • is most prevalent in terms of geographic scope and population
  • treats Qur’anic proscriptions as inherently based on God’s rational nature and, by extension, favors human rationality, with some limitations
  • supports analogical reasoning and maintains strict criteria as to which hadith form the basis of the Sunnah
  • embraces doctrines such as equity to avoid restrictive textual arguments that deny justice


  • is second-most prevalent by population
  • is traditionalist, with a focus on textual prescriptions of the Qur’an and Sunnah; Shaf’i limits independent analogical reasoning
  • supports an expansive view of which hadith may constitute the Sunnah
  • rejects doctrines such as equity and instead maintains strict adherence to textual concerns


  • is third-most prevalent by population
  • focuses on the traditions of the Madinah people who either lived during or immediately after the life and reign of the Prophet Muhammad
  • emphasizes communal reflection of the Sunnah, favoring broad-based positions on collective good
  • embraces textual prescriptions as well as concepts like maslahah (for public benefit)


  • is fourth-most prevalent by population; Hanbali is followed in the Gulf States
  • maintains the most literal approach to the Qur’an, with strict criteria regarding which hadith constitute the Sunnah; its adherence to literalism also permits all things not explicitly prohibited
  • limits legal doctrines that allow for textual departures, including reasoning by analogy


  • is the primary school of law for Twelver Shi’ism
  • embraces the concept of the Imamate: the twelve bloodline descendants of the Prophet Muhammad guide the community of believers; these recognized descendants or Imams are considered infallible (they do not commit sin)
  • affirms not only the traditions of the Prophet Muhammad but also those of the Imams
  • mandates the concept of “Taqleed” whereby believers who do not have expertise follow the instruction of expert scholars
  • favors the concept of ’aql (literally intellect, but meaning reasoning by logic) instead of the Sunni doctrine of qiyas; scholars adopt a position on an issue by using intellect or logic to deduce the law