The function of the rational soul is to think, but she does not limit
herself to thinking. Otherwise there would be no difference between her
and intelligence. Besides her intellectual characteristics, the soul's
characteristic nature, by virtue of which she does not remain mere
intelligence, has a further individual function, such as is possessed
by every other being. By raising her glance to what is superior to her,
she thinks; by bringing them down to herself, she preserves herself; by
lowering them to what is inferior to her, she adorns it, administers
it, and governs it. All these things were not to remain immovable in
the intelligible world, to permit of a successive issue of varied
beings, which no doubt are less perfect than that which preceded them,
but which, nevertheless, exist necessarily during the persistence of
the Principle from which they proceed.