d substances are above us in the order of nature;
hence man can have happiness of a kind by knowing the separated
substances, although his perfect happiness consists in knowing the
first substance, namely, God. But it is quite natural for one
separate substance to know another; as it is natural for us to know
sensible natures. Hence, as man's happiness does not consist in
knowing sensible natures; so neither does the angel's happiness
consist in knowing separated substances.

Reply Obj. 2: What is most manifest in its nature is hidden from us
by its surpassing the bounds of our intellect; and not merely because
our intellect draws knowledge from phantasms. Now the Divine
substance surpasses the proportion not only of the human intellect,
but even of the angelic. Consequently, not even an angel can of his
own nature know God's substance. Yet on account of the perfection of
his intellect he can of his nature have a higher knowledge of God
than man can have. Such knowledge of God remains also in the demons.
Although they do not possess the purity which comes with grace,
nevertheless they have purity of nature; and this suffices for the
knowledge of God which belongs to them from their nature.

Reply Obj. 3: The creature is darkness in comparison with the
excellence of the Divine light; and therefore the creature's
knowledge in its own nature is called "evening" knowledge. For the
evening is akin to darkness, yet it possesses some light: but when
the light fails utterly, then it is night. So then the knowledge of
things in their own nature, when referred to the praise of the
Creator, as it is in the good angels, has something of the Divine
light, and can be called evening knowledge; but if it be not referred
to God, as is the case with the demons, it is not called evening, but
"nocturnal" knowledge. Accordingly we read in Gen. 1:5 that the
darkness, which God separated from the light, "He called night."

Reply Obj. 4: All the angels had some knowledge from the very
beginning respecting the mystery of God's kingdom, which found its
completion in Christ; and most of all from the moment when they were
beatified by the vision of the Word, which vision the demons never
had. Yet all the angels did not fully and equally apprehend it; hence
the demons much less fully understood the mystery of the Incarnation,
when Christ was in the world. For, as Augustine observes (De Civ. Dei
ix, 21), "It was not manifested to them as it was t