"The acts of madmen...are beyond that which a sane man can envision."
And concerning both universals and individuals it is true of [God] that He knows them and does not know them. This is the conclusion to which the principles of the ancient philosophers led.--Averroës The Incoherence of Incoherence, Ch. 11.
Averroës, who had written his commentary on the Republic, might have said that the mother of the Book is similar, in a way, to the Platonic Idea, but he could see that theology was one subject utterly beyond the grasp of abu-alHasan.--Borges (translated by Andrew Hurley).
In the third quote above, Borges shows us the self-command of the great Spanish philosopher, whose silence, paradoxically, keeps conversation going (the essence of civilization) with those less capable of first philosophy. In so showing Borges refutes, so to speak, the claim of one of the speakers in his tale, La Busca de Averroes -- commonly translated as Averroës's Search but there is something to be said, too, for Averroës's Hunt --, who had said, "A single speaker could tell anything, no matter how complex it might be." (Emphasis in original.) In context, the speaker is offering an efficiency claim: rather than showing things by way of multiple characters, it is more efficient and less confusing to tell things in proper order. It is worth noting that the speaker (a traveller) endorses, perhaps without fully grasping it, the doctrine of Rationalism--all can be articulated. There is no denying that Rationalism is a useful heuristic, but it does not follow that it is true even if we grant the speaker and his agreeable interlocuters (who show that a symposium does not require wine) that Rationalism does not flounder on complexity as such (nor does it flounder on the fact that some things are beyond the grasp of most speakers). Earlier in the tale, Borges gives more instances of the same point: for example, he describes feeling as beyond, in some sense, the working of the intellect ("the shaping of syllogisms and linking together of vast paragraphs did not keep him from feeling.")
In the story, Borges, lets a very Humean Averroës distinguish between nature and art; accordingly, grasping natural essences is easier than grasping linguistic meaning ("both birds and the fruit of trees belong to the natural world, while writing is an art. To move from leaves to birds is easier than to move from roses to letters.") For, texts generate multiplicity if you wait long enough and apply imagination and belief. The character, Averroës tells us this poetically, "Time widens the circle of the verses, and I myself know some verses that are, like music, all things to all men." Rather than treating this as an indictment of poetry, or the Quran, Borges lets his philosopher say that the poetic is the only enterprise capable of true profit over time: "then time, which ravages fortresses and great cities, only enriches poetry." (Emphasis added.)
There is an ironic alternative, of course: poetic madness is required to grasp what is previously unsayable. This would entail that Rationalism's Principle of Sufficient Reason is not founded on necessity, but on -- to use an old-fashioned word -- inspiration.*
* "Interpreting Aristotle's works, in the same way the ulemas interpret the Qur'an, was the hard task that Averroës had set himself."