le, whoever knows a man, knows an animal by proper knowledge; and
whoever knows the number six, knows the number three also by proper
knowledge.

As therefore the essence of God contains in itself all the perfection
contained in the essence of any other being, and far more, God can
know in Himself all of them with proper knowledge. For the nature
proper to each thing consists in some degree of participation in the
divine perfection. Now God could not be said to know Himself perfectly
unless He knew all the ways in which His own perfection can be shared
by others. Neither could He know the very nature of being perfectly,
unless He knew all modes of being. Hence it is manifest that God knows
all things with proper knowledge, in their distinction from each
other.

Reply Obj. 1: So to know a thing as it is in the knower, may be
understood in two ways. In one way this adverb "so" imports the mode
of knowledge on the part of the thing known; and in that sense it is
false. For the knower does not always know the object known according
to the existence it has in the knower; since the eye does not know a
stone according to the existence it has in the eye; but by the image
of the stone which is in the eye, the eye knows the stone according
to its existence outside the eye. And if any knower has a knowledge
of the object known according to the (mode of) existence it has in
the knower, the knower nevertheless knows it according to its (mode
of) existence outside the knower; thus the intellect knows a stone
according to the intelligible existence it has in the intellect,
inasmuch as it knows that it understands; while nevertheless it knows
what a stone is in its own nature. If however the adverb 'so' be
understood to import the mode (of knowledge) on the part of the
knower, in that sense it is true that only the knower has knowledge
of the object known as it is in the knower; for the more perfectly
the thing known is in the knower, the more perfect is the mode of
knowledge.

We must say therefore that God not only knows that all things are in
Himself; but by the fact that they are in Him, He knows them in their
own nature and all the more perfectly, the more perfectly each one is
in Him.

Reply Obj. 2: The created essence is compared to the essence of God
as the imperfect to the perfect act. Therefore the created essence
cannot sufficiently lead us to the knowledge of the divine essence,
but rather the converse.

Reply Obj.