ur very essence is characterized by reason, this our summit
is rational, and though it subsists in energy, yet it has a remitted union
with things themselves. Though too it energizes from itself, and contains
intelligibles in its essence, yet from its alliance to the discursive
nature of soul, and its inclination to that which is divisible, it falls
short of the perfection of an intellectual essence and energy profoundly
indivisible and united, and the intelligibles which it contains degenerate
from the transcendently fulged and self-luminous nature of first
intelligibles. Hence, in obtaining a perfectly indivisible knowledge, it
requires to be perfected by an intellect whose energy is ever vigilant
and unremitted; and it's intelligibles, that they may become perfect,
are indigent of the light which proceeds from separate intelligibles.
Aristotle, therefore, very properly compares the intelligibles of our
intellect to colors, because these require the splendour of the sun, and
denominates an intellect of this kind, intellect in capacity, both on
account of its subordination to an essential intellect, and because it is
from a separate intellect that it receives the full perfection of its
nature. The middle part of the rational soul is called by Plato, dianoia,
and is that power which, as we have already said, reasons scientifically,
deriving the principles of its reasoning, which are axioms from intellect.
And the extremity of the rational soul is opinion, which in his Sophista
he defines to be that power which knows the conclusion of dianoia. This
power also knows the universal in sensible particulars, as that every man
is a biped, but it knows only the oti, or that a thing is, but is ignorant
of the dioti, or why it is: knowledge of the latter kind being the province
of the dianoetic power.

And such is Plato's division of the rational part of our nature, which he
very justly considers as the true man; the essence of every thing
consisting in its most excellent part.

After this follows the irrational nature, the summit of which is the
phantasy, or that power which perceives every thing accompanied with
figure and interval; and on this account it may be called a figured
intelligence ([Greek: morphotike noesis]). This power, as Jamblichus
beautifully observes, groups upon, as it were, and fashions all the
powers of the soul; exciting in opinion the illuminations from the
senses, and fixing in that life which is extended