Iqbal takes up ijmāʿ — 'perhaps the most important legal notion in Islam' — and argues for its transformation from a theoretical idea into a functioning legislative assembly, diagnosing that it never became institutional because the Umayyad and Abbasid monarchies feared any collective body that might check their power. The ʿulamāʾ should participate as contributing members alongside laymen with 'keen insight into affairs,' and educational reform, not clerical supervision, is the remedy for interpretive error.
Section 12 examined the second source of Islamic law — the ḥadīth — and, drawing on Shāh Walī Allāh's theory of prophetic method, argued that the legal traditions embody context-specific applications of universal principles rather than universal prescriptions, and that Abū Ḥanīfah's principled reluctance to rely on them should guide modern Muslim liberalism. Section 13 now takes up the third source: ijmāʿ (consensus), which Iqbal calls 'perhaps the most important legal notion in Islam' — and argues for its transformation from an abstract idea into a concrete legislative institution.
The section advances through four major arguments. First, Iqbal diagnoses why ijmāʿ 'remained practically a mere idea, and rarely assumed the form of a permanent institution': it was contrary to the political interests of the Umayyad and Abbasid absolute monarchies, who preferred to leave ijtihād to individual mujtahids rather than risk the formation of a collective legislative body that 'might become too powerful for them.' Second, he argues that the modern formation of legislative assemblies in Muslim lands represents the institutional realisation of ijmāʿ — that the transfer of ijtihād from individual scholars to elected assemblies is 'the only possible form ijmāʿ can take in modern times,' and that this transfer will bring the contributions of laymen with 'keen insight into affairs' alongside the technical expertise of the ʿulamāʾ.
Third, Iqbal addresses three technical jurisprudential questions: whether ijmāʿ can repeal the Qur'an (no — the word naskh in early juristic discussions meant the power to extend or limit a Qur'anic rule's application, not to supersede it); whether later generations are bound by the decisions of the Companions (yes for matters of fact, no for matters of interpretation, on the authority of al-Karkhī); and how to prevent a legislative assembly of non-specialists from making interpretive errors (not through an ecclesiastical supervisory committee — the Persian model, which Iqbal calls 'dangerous' — but through the reform of legal education). Fourth, Iqbal closes with the practical recommendation that the ʿulamāʾ should participate in legislative assemblies as contributing members rather than external supervisors, and that the 'only effective remedy' for erroneous interpretation is educational reform: extending the sphere of Islamic legal education and combining it with 'an intelligent study of modern jurisprudence.'
This section is pivotal because it is where the Reconstruction's philosophical argument meets institutional design. The permanence/change dialectic of Section 1, the diagnosis of stagnation in Section 2, the Turkish case study of Sections 4–9, the hermeneutic principles of Sections 11–12 — all converge on a single institutional proposal: the transformation of ijmāʿ from a theoretical principle into a functioning legislative assembly. This is Iqbal at his most practically constructive, offering not merely philosophical arguments but institutional prescriptions.