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

And that one and the same existent can have different degrees of
existence can be shown from what occurs with colour . For we find that
colour has different degrees of existence, some higher than others; the
lowest degree is its existence in matter, a higher degree is its existence in
sight, for it exists in such a way that the colour becomes conscious of
itself, whereas existence in matter is an inorganic existence without
consciousness; further, it has been proved in the science of psychology
that colour has also an existence in the imaginative faculty, and this is a
superior existence to its existence in the faculty of sight; it has equally
been shown that it has an existence in the remembering faculty superior to
that in the imaginative faculty,s and, finally, it has in the intellect an
existence superior to all these existences. Now, in the same way, we are
convinced that it has in the essence of the First Knowledge an existence
superior to all its other existences, and that this is the highest degree of
existence possible.
As for what Ghazali mentions concerning the philosophical theory of the
order in the emanation of these separate principles and of the number of
entities which emanate out of each of them, there is no proof that this
really takes place and that this happens exactly in this way; and the form
in which Ghazali relates it is therefore not to be found in the works of the
ancient philosophers. But these philosophers all agree on the theory that
the principles, both separate and nonseparate, all emanate from the First
Principle, and that through the emanation of this unique power the world in
its totality becomes a unity, and that through this power all its parts are
connected, so that the universe aims at one act, as happens with the one
body of an animal; which, however, has different potencies, members, and
acts; and indeed the world is according to the learned one and the same
existent only because of this one power which emanates from the First
Principle. And they agree about all this, because according to them the
heavens are like a single animal and the daily movement which is
common to all the heavens is like the animal’s general movement in
space, and the particular movements which the different parts of heaven
have are like the particular movements of the members of the animal. And
the philosophers had already proved that there is one power in the animal
through which it becomes one and through which all the potencies which it
possesses tend towards one act, that is, towards the preservation of the
animal,’ and all these potencies are connected with the potency which
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