his opponent has cited as necessary knowledge, by means of an inferential argument. For he says that reason allows this possibility, and allowing this possibility entails allowing that one. Yet challenging necessary knowledge by means of inferential arguments is unacceptable, because necessary knowledge is the foundation of inferential knowledge. If inferential arguments could validly undermine necessary knowledge, this would undermine the very foundation of inferential knowledge; and undermining a thing’s foundation undermines the thing itself. Thus, challenging necessary knowledge by means of inferential arguments entails undermining both necessary and inferential knowledge. Since, on this supposition, neither necessary nor inferential knowledge would be valid, this would be neither knowledge nor sound discourse, and so could not undermine anything.

This is the kind of discourse that the early generations of the Muslim community and its leading scholars unanimously condemned. As has been said:

Arguments that shatter like glass—you think them true,
Yet each breaks another and is itself broken.

If challenging necessary knowledge by means of inferential arguments entails that neither constitutes knowledge and that neither is established as true and sound, then the critic’s argument