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

I say:
they are therefore two things, whereas the existence of its
essence without the existence of its essence cannot be
imagined, and if the knowledge of all things formed a unity, it
would be impossible to imagine this duality. Therefore all
those philosophers who acknowledge that the First knows
something besides its own essence have undoubtedly at the
same time acknowledged a plurality.
The summary of this objection to the proposition that the First knows
both itself and something else is that knowing one’s self is different from
knowing something else. But Ghazali falls here into confusion. For this can
be understood in two ways: first, that Zaid’s knowledge of his own
individuality is identical with his knowledge of other things, and this is not
true; secondly, that man’s knowledge of other things, namely of existents,
is identical with the knowledge of his own essence, and this is true. ‘ And
the proof is that his essence is nothing but his knowledge of the existents.
z For if man like all other beings knows only the quiddity which
characterizes him, and if his quiddity is the knowledge of things, then
man’s self-knowledge is necessarily the knowledge of all other things, for
if they were different his essence would be different from his knowledge of
things. This is clear in the case of the artisan, for his essence, through
which he is called an artisan, is nothing but his knowledge of the products
of art. ; And as to Ghazali’s words, that if his self-knowledge were identical
with his knowledge of other things, then the negation of the one would be
the negation of the other and the affirmation of the one the affirmation of
the other, he means that if the self-consciousness of man were identical
with his knowledge of other things, he could not know his own self without
knowing the other things; that is, if he were ignorant of other things, he
would not know his own self, and this proposition is in part true, in part
false. For the quiddity of man is knowledge, and knowledge is the thing
known in one respect and is something different in another. And if he is
ignorant of a certain object of knowledge, he is ignorant of a part of his
essence, and if he is ignorant of all knowables, he is ignorant of his
essence; and to deny man this knowledge is absolutely the same as to
deny man’s selfconsciousness, for if the thing known is denied to the
knower in so far as the thing known and knowledge are one, man’s self-
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