What Is Ijma in Islam? Definition, Conditions and Significance

Definition of Ijma

In classical usul al-fiqh (the principles of Islamic jurisprudence), Ijma is defined narrowly and precisely: it is not simply popular agreement among ordinary Muslims, but the specific, verified consensus of mujtahids — jurists qualified to exercise independent legal reasoning — living in a given era, on a ruling not already fixed by revealed text. This precision matters because it distinguishes Ijma as a formal legal source from general cultural consensus or scholarly opinion that falls short of unanimous agreement.

Ijma among the sources of Islamic law

Sunni Islamic jurisprudence recognises four principal sources of law, ranked in order of authority:

Ijma cannot contradict the Quran or Sunnah — it operates strictly within the space those two sources leave open, which is precisely what gives it legitimacy as a binding source rather than an independent innovation in religious law.

Conditions for a valid Ijma

• The consensus must be reached by qualified jurists (mujtahids) competent to exercise independent legal reasoning, not by the general Muslim population.
• It must concern a matter on which the Quran and Sunnah do not already provide a clear, unambiguous ruling.
• The agreement must be genuine and complete among the jurists of a given era, not a majority opinion with recorded dissent.
• Once validly formed, classical theory holds that a sound Ijma cannot later be reversed by a subsequent, smaller consensus.

These conditions explain why genuine Ijma is considered relatively rare in later Islamic history compared to the early Islamic period, when the community of qualified scholars was smaller and more geographically concentrated, making unanimous agreement more achievable.

Historical examples of Ijma

The most frequently cited historical example is the compilation of the Quran into a single standardized written text — first collected under Caliph Abu Bakr after concern that reciters who had memorised the Quran were being lost in early battles, then standardised into one authoritative text under Caliph Uthman to prevent regional recitation disputes. Scholars point to the community and companions' agreement on this process as an early demonstration of consensus resolving a practical necessity that revelation did not explicitly detail. Other frequently cited examples include early consensus on specific inheritance shares and on aspects of congregational prayer not explicitly detailed in the primary texts.

Ijma vs Qiyas: two distinct sources

Ijma and Qiyas are often confused because both are used to address situations the Quran and Sunnah do not directly cover, but they work differently. Ijma is a state of agreement — jurists converge on a single answer, often after some may have initially applied different reasoning. Qiyas is a method — it extends an existing, established ruling to a new case by identifying a shared underlying legal cause (illah) between the two. In practice, Qiyas is frequently the reasoning process jurists use on the way to reaching an Ijma, but the two remain analytically distinct sources in classical jurisprudence.

Using Ijma in CSS Islamic Studies answers

A strong answer on Ijma should define it precisely as jurist consensus rather than general agreement, place it correctly as the third source after the Quran and Sunnah, name at least one concrete historical example such as Quranic compilation, and briefly distinguish it from Qiyas rather than treating the two as interchangeable. For the paper's broader themes and answer architecture, see the full Islamic Studies syllabus and answer strategy guide.