speech in the true sense, you are thereby unable to establish its existence or to assert that it constitutes genuine speech. For they argue for the necessity of truthfulness for Allah by saying that inner speech cannot admit falsehood, since knowledge is obligatory for Him and ignorance impossible.(1) This proof is cited by all of their leading authorities; even Fakhr al-Dīn al-Rāzī mentions it, though he adds that it proves only the truthfulness of the inner speech, not the truthfulness of the letters that give expression to it.

And if it were admissible for a living being to possess a mental judgment of which he is unaware, does not affirm, does not even suppose, but rather knows the very opposite, then it would be impossible to say that this mental judgment necessarily entails knowledge, or that it must accord with knowledge so that it cannot be false.(2) What they have said is an intrinsic contradiction, not merely a contradiction in what follows from it. For when they maintained that the meaning of a report is not knowledge, they thereby posited a mental judgment that contradicts knowledge, making it liable to be false and to exist alongside the absence of knowledge. Yet when they affirmed truthfulness they said: “The meaning of a report—that is, this mental judgment—cannot be realised without knowledge or in opposition to it; therefore it cannot be false.”(3)

Abū al-Qāsim al-Anṣārī,(4) the teacher of al-Shahrastānī and disciple of Abū al-Maʿālī, says in his commentary on the Irshād:

Section: The speech of Allah is true, and the proof of that is the consensus of the Muslims; and falsehood