Tahafut_al-Tahafut-transl-Engl-van-den-Bergh

I say:
as sight differs from touch through the fact that touch, like
taste, can only come to perceive by being in contact with the
object touched, whereas separation from the object is a
condition of sight, so that when the eyelids cover the eye it
does not see the colour of the eyelid, ‘ not being at a
distance from it. , But this difference does not necessitate
that they should differ in their need to be in a body, and it is
not impossible that there should be among the senses
something called intellect that differs from the others in that it
perceives itself.
The first objection, that the usual course of events might be interrupted
so that sight might see itself, is an argument of the utmost sophistry and
imposture, and we have discussed it already. As to the second objection,
that it is not impossible that a bodily perception should perceive itself, this
has a certain plausibility, but when the motive is known which led the
philosophers to their assertion, then the impossibility of this supposition
becomes clear, for perception is something which exists between the
agent and the patient, and it consists of the perceiver and the perceived. It
is impossible that a sense should be in one and the same respect its own
agent and patient, and the duality of agent and patient in sense arises, as
concerns its act, from the side of the form and, as concerns its passivity,
from the side of the matter. But no composite can think itself, because if
this were so, its essence would be different from that by which it thinks, for
it would think only with a part of its essence; and since intellect and
intelligible are identical, I if the composite thought its essence, the
composite would become a simple, and the whole the part, and all this is
impossible. When this is established here in this way, it is only a dialectical
proof; but in the proper demonstrative order, i. e. preceded by the
conclusions which ought to precede it, it can become a necessary one.
Ghazali says:
The sixth proof is that they say that, if the intellect
perceived through a bodily organ like sight, it would be just
as incapable of perceiving its own organ as the other
senses; but it perceives the brain and the heart and what is
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