This is further made clear by the fact that affirming knowledge and negating it are contradictory. If affirming it amounts to nonexistence, then negating it amounts to existence. It would therefore follow that, when we say, “He does not know,” we are affirming something. Clearly, this turns realities upside down.

As for his statement:

“What indicates that this much is sufficient is that seeing consists merely in the relation whereby a thing is manifest to the one who sees it, with no veil intervening.”

The reply is: If you claim that seeing—which is the manifestation of the object seen to sight—is a relation amounting to sheer nonexistence, then this premise is subject to the same objection as the claim itself. For when a person sees, he senses within himself something positive, different from his state when he does not see, just as he finds within himself something positive when he knows.

Thus, claiming that seeing amounts to nonexistence is like claiming that knowledge amounts to nonexistence. Both claims imply that sense perception and reason amount to nonexistence, and that observing sensible things and knowing intelligible things amount to nonexistence.

It is well known that someone who has neither seen something nor known it lacks both sight and knowledge of it. If, after seeing and knowing it, he has acquired nothing but nonexistence, then there is no difference between seeing and knowing, on the one hand, and neither seeing nor knowing, on the other. This equates the blind with the seeing, and the knowledgeable with the ignorant.