Ijma

Ijma (Arabic: إجماع, romanized: ijmāʿ, lit. 'consensus', IPA: [ʔid͡ʒ.maːʕ]) is an Arabic term referring to the consensus or agreement of the Islamic community on a point of Islamic law. Sunni Muslims regard it as one of the secondary sources of Sharia law, after the Qur'an, and the Sunnah. Exactly what group should represent the Muslim community in reaching the consensus is not agreed on by the various schools of Islamic jurisprudence. Some believe it should be the Sahaba (the first generation of Muslims) only; others the consensus of the Salaf (the first three generations of Muslims); or the consensus of Islamic lawyers, the jurists and scholars of the Muslim world, i.e. scholarly consensus; or the consensus of all the Muslim world, both scholars and lay people.

It was the consensus that could in principle elevate a ruling based on probable evidence to absolute certainty. This classical doctrine drew its authority from a series of hadiths stating that the Islamic community could never agree on an error. This form of consensus was technically defined as agreement of all competent jurists in any particular generation, acting as representatives of the community. However, the practical difficulty of obtaining and ascertaining such an agreement meant that it had little impact on legal development. A more pragmatic form of consensus, which could be determined by consulting works of prominent jurists, was used to confirm a ruling so that it could not be reopened for further discussion. The cases for which there was a consensus account form less than 1 percent of the body of classical jurisprudence.

The opposite of Ijma (i.e., lack of consensus on a point of Islamic law) is called ikhtilaf.