Ijma

Ijmāʿ (Arabic: إجماع‎‎) is an Arabic term referring to the consensus or agreement of the Muslim scholars basically on religious issues. Various schools of thought within Islamic jurisprudence may define this consensus to be that of the first generation of Muslims only; or the consensus of the first three generations of Muslims; or the consensus of the jurists and scholars of the Muslim world, or scholarly consensus; or the consensus of all the Muslim world, both scholars and laymen.

The hadith of Muhammad which states that if that "My ummah will never agree upon an error"is often cited as a proof for the validity of ijmā'. Sunni Muslims regard ijmā' as the third fundamental source of Sharia law, just after the divine revelation of the Qur'an, and the prophetic practice known as Sunnah. While there are differing views over who is considered a part of this consensus, the majority view is split between two possibilities: that religiously binding consensus is the consensus of the entire Muslim community, or that religiously binding consensus is just the consensus of the religiously learned. The names of two kinds of consensus are:

Malik ibn Anas held the view that the religiously binding consensus was only the consensus of Muhammad's companions and the direct successors of those companions in the city of Medina.

According to Iraqi academic Majid Khadduri, Al-Shafi'i held the view that religiously binding consensus had to include all of the Muslim community in every part of the world, both the religiously learned and the layman. Thus, if even one individual out of millions would hold a differing view, then consensus would not have been reached. In an attempt to define consensus in a form which was more likely to ever occur, Al-Ghazali expanding on al-Shafi'i's definition to define consensus as including all of the Muslim community in regard to religious principles and restricting the meaning to only the religiously learned in regard to finer details.

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