our faith, is God Himself, Who is the
soul's Creator, and only beatitude; as will be shown later on (Q. 90,
A. 3; I-II, Q. 3, A. 7). Wherefore the human soul derives its
intellectual light from Him, according to Ps. 4:7, "The light of Thy
countenance, O Lord, is signed upon us."

Reply Obj. 1: That true light enlightens as a universal cause, from
which the human soul derives a particular power, as we have explained.

Reply Obj. 2: The Philosopher says those words not of the active
intellect, but of the intellect in act: of which he had already said:
"Knowledge in act is the same as the thing." Or, if we refer those
words to the active intellect, then they are said because it is not
owing to the active intellect that sometimes we do, and sometimes we
do not understand, but to the intellect which is in potentiality.

Reply Obj. 3: If the relation of the active intellect to the passive
were that of the active object to a power, as, for instance, of the
visible in act to the sight; it would follow that we could understand
all things instantly, since the active intellect is that which makes
all things (in act). But now the active intellect is not an object,
rather is it that whereby the objects are made to be in act: for
which, besides the presence of the active intellect, we require the
presence of phantasms, the good disposition of the sensitive powers,
and practice in this sort of operation; since through one thing
understood, other things come to be understood, as from terms are
made propositions, and from first principles, conclusions. From this
point of view it matters not whether the active intellect is
something belonging to the soul, or something separate from the soul.

Reply Obj. 4: The intellectual soul is indeed actually immaterial,
but it is in potentiality to determinate species. On the contrary,
phantasms are actual images of certain species, but are immaterial in
potentiality. Wherefore nothing prevents one and the same soul,
inasmuch as it is actually immaterial, having one power by which it
makes things actually immaterial, by abstraction from the conditions
of individual matter: which power is called the "active intellect";
and another power, receptive of such species, which is called the
"passive intellect" by reason of its being in potentiality to such
species.

Reply Obj. 5: Since the essence of the soul is immaterial, created by
the supreme intellect, nothing prevents that power which it derives