And whatever means is envisaged—gestures, speech, writing, or otherwise—it belongs to the category of knowledge gained through hearing and transmission, for what unites all these means is that they convey another person’s intent. If someone denies this by advancing a rational argument that he considers to conflict with it, anyone who affirms what he knows through communication must offer him an answer. An analogous answer can then be given by those who affirm what they know the Messenger, may Allah bless him and grant him peace, intended. This has been discussed at length elsewhere.

[The Ninth Answer]

It may be said:

We are not content to answer you as you answered the deniers.

For you fall short in debating those who deny what you affirm on the basis of reason and transmitted teachings. In many of your debates with them, you resort to obstinate denial and claims whose opposite they know to be true. This is what you do concerning seeing Allah, His speech, and affirming His attributes without affirming their necessary implications. You often affirm something without its necessary implications, or while also affirming something incompatible with it.

This is how the Qarmatians, the philosophers, the Muʿtazilah, and other such deniers gained the upper hand over you. Your leading scholars’ arguments against them are inadequate, and their inadequacy is apparent to anyone well versed in rational arguments.

The reason is that they fell short in debating them: they conceded rational premises that they thought sound but that were unsound. They therefore had to affirm the necessary implications of those premises and were forced either to agree with them in falsehood, to fall into contradictions that exposed the unsoundness of their position, or to prove unable to respond, thereby exposing their shortcomings and inability to sustain their argument.