by “agreement” he means the shared adherence in belief, word, or deed; and he restricts it to the mujtahid scholars, for the concurrence of the lay-people carries no legal weight."
I say: al-Ghazālī uses the word “agreement” without tying it to any particular era. In al-Mustasfā (p. 137) he writes: “The exclusive agreement of the community of Muhammad ﷺ on some religious matter.”
Al-Āmidī comments on this definition in al-Iḥkām (1/180): “It is defective in three respects:
- What he has stated suggests that ijmāʿ will never be realized until the Day of Resurrection, for the community of Muhammad in its entirety comprises everyone who follows him until that Day, whereas those found in any one era constitute only a part of the community, not the whole of it. This is not the position of al-Ghazālī, nor of anyone who affirms the existence of ijmāʿ.
- Even granting that those living in a given age are part of the community of Muhammad, his wording entails that if some era were devoid of qualified scholars and consisted solely of lay-people, and they agreed on a religious question, their concurrence would amount to a legal ijmāʿ. That is plainly untenable.
- By limiting ijmāʿ to agreement on a religious matter, his definition would exclude the community’s consensus on intellectual or customary issues from being a binding proof, yet that, too, is unsound, as will be shown.
What is correct, therefore, is to say: ijmāʿ is the agreement of all those vested with authority and expertise from the community of Muhammad, in a given era, on the ruling of a particular case—provided we hold that lay-people are not counted in ijmāʿ. If, however, they are to be included, then one should say: ijmāʿ is the agreement of all legally responsible members of the community of Muhammad… to the end of his definition.”
I add: al-Āmidī’s view that ijmāʿ is not confined to religious matters is shared by al-Shawkānī, who states in Irshād al-Fuḥūl (p. 132), “It encompasses legal, rational, and linguistic questions.”
The same position is taken by al-Subkī, as recorded in Jamʿ al-Jawāmiʿ, and by al-Zarkashī in al-Baḥr al-Muḥīṭ.