Since the isthmus is something that separates the known from the unknown, between the non-existent and the existing, between the negated and the affirmed, and between the intelligible and the intelligible, it is called an isthmus by terminology, and it is intelligible in itself and is nothing but imagination. If you realize it and you are rational, you know that you have realized something existentially that your sight has fallen upon and you have never known what it is, with evidence that it is nothing and then something. First and foremost, what is this thing that has been proven to have existential objectivity and you have denied it in the event that you prove it ? There is neither known nor unknown ]

Imagination is neither existent nor non-existent nor known nor unknown nor negated nor affirmed. How much a person perceives his image in the mirror, he knows with certainty that he perceived his image with a face, and he knows with certainty that he did not perceive his image with a face because of the accuracy he sees in it. If the body of the mirror is small and he knows that his image is larger than the one he saw by an infinitesimal degree, and if the body of the mirror is large and he sees his image extremely large, he is certain that his image is smaller than what he saw, and he cannot deny that he saw his image and he knows that his image is not in the mirror, nor is it between him and the mirror, nor It is the reflection of the rays of Basra into the image visible in it from outside, whether it was his image or something else, since if it were like that, he would perceive the image in its magnitude and what it is, and in seeing it in the sword from length or width, what we mentioned will become clear to you, with his knowledge that he saw his image.