“Whoever claims to have the Ijmaa’ of the Muslim scholars of his age on a given religious issue has made a gross claim (‘athama ad-da’wa) and asserted its existence with something which does not obtain. The feasibility of this is impossible, even If one assumes that it is possible to have such agreement, without investigation and knowledge of the opinions of each man or group of men. The truth is that this is impossible (mamnoo’). This is because the consensus of all the scholars of all the regions on an issue is impossible given the [existence of] different schools, temperaments, and differences in understanding, contradictory dispositions and the love of contradiction. This is with regards to a scholar speaking about the consensus of his generation. If he is claiming an ijmaa’ about a generation which he did not know after the age of the companions then the claim, is too impossible… The one who claims that ijmaa’ constitutes proof is not correct, for such [a claim] constitutes mere conjecture on the part of an individual from the community of Muslims. No believer can worship Allaah on the basis of this… In my works, when I report a consensus from others I do this in order to prove my point to the one who accepts that Ijmaa’ constitutes proof.”

[Wabl Al Ghamaan ‘alaa Shifaa’ Al-Uwaam in Kitaab Shifaa’ Al Uwaam 3 vols]