This may be seen still more clearly by considering how this double
nature shows itself in all that thinks in a clearer manner. We assert
that all essences, as such, that all things that are by themselves, and
that possess true existence, are located in the intelligible world.
This happens not only because they always remain the same, while
sense-objects are in a perpetual flow and change[13]--although, indeed,
there are sense-objects (such as the stars[14]), that remain the
same--but rather because they, by themselves, possess the perfection
of their existence. The so-called primary "being" must possess an
existence which is more than an adumbration of existence, and which is
complete existence. Now existence is complete when its form is thought
and life. Primary "being," therefore, will simultaneously contain
thought, existence and life. Thus the existence of essence will imply
that of intelligence; and that of intelligence, that of essence; so
that thought is inseparable from existence, and is manifold instead of
being one. That which is not manifold (the One), cannot, therefore,
think. In the intelligible world, we find Man, and the thought of
man, Horse and the thought of horse, the Just Man and the thought of
the just man; everything in it is duality; even the unity within it
is duality, and in it duality passes into unity. The First is neither
all things that imply duality, nor any of them; it contains no duality
whatever.