eds be some proportion between the object
and the faculty of knowledge; such as of the active to the passive,
and of perfection to the perfectible. Hence that sensible objects of
great power are not grasped by the senses, is due not merely to the
fact that they corrupt the organ, but also to their being
improportionate to the sensitive power. And thus it is that
immaterial substances are improportionate to our intellect, in our
present state of life, so that it cannot understand them.

Reply Obj. 4: This argument of the Commentator fails in several ways.
First, because if separate substances are not understood by us, it
does not follow that they are not understood by any intellect; for
they are understood by themselves, and by one another.

Secondly, to be understood by us is not the end of separate
substances: while only that is vain and purposeless, which fails
to attain its end. It does not follow, therefore, that immaterial
substances are purposeless, even if they are not understood by us
at all.

Reply Obj. 5: Sense knows bodies, whether superior or inferior, in
the same way, that is, by the sensible acting on the organ. But we do
not understand material and immaterial substances in the same way.
The former we understand by a process of abstraction, which is
impossible in the case of the latter, for there are no phantasms of
what is immaterial.
_______________________

SECOND ARTICLE [I, Q. 88, Art. 2]

Whether Our Intellect Can Understand Immaterial Substances Through Its
Knowledge of Material Things?

Objection 1: It would seem that our intellect can know immaterial
substances through the knowledge of material things. For Dionysius
says (Coel. Hier. i) that "the human mind cannot be raised up to
immaterial contemplation of the heavenly hierarchies, unless it is
led thereto by material guidance according to its own nature."
Therefore we can be led by material things to know immaterial
substances.

Obj. 2: Further, science resides in the intellect. But there are
sciences and definitions of immaterial substances; for Damascene
defines an angel (De Fide Orth. ii, 3); and we find angels treated of
both in theology and philosophy. Therefore immaterial substances can
be understood by us.

Obj. 3: Further, the human soul belongs to the genus of immaterial
substances. But it can be understood by us through its act by which
it understands material things. Therefore also other material
substances can be underst