Objection 1. It would seem that the intellectual soul does not know material things in the eternal types. For that in which anything is known must itself be known more and previously. But the intellectual soul of man, in the present state of life, does not know the eternal types: for it does not know God in Whom the eternal types exist, but is "united to God as to the unknown," as Dionysius says (Myst. Theolog. i). Therefore the soul does not know all in the eternal types.
Objection 2. Further, it is written (Romans 1:20) that "the invisible things of God are clearly seen... by the things that are made." But among the invisible things of God are the eternal types. Therefore the eternal types are known through creatures and not the converse.
Objection 3. Further, the eternal types are nothing else but ideas, for Augustine says (QQ. 83, qu. 46) that "ideas are permanent types existing in the Divine mind." If therefore we say that the intellectual soul knows all things in the eternal types, we come back to the opinion of Plato who said that all knowledge is derived from them.
On the contrary, Augustine says (Confess. xii, 25): "If we both see that what you say is true, and if we both see that what I say is true, where do we see this, I pray? Neither do I see it in you, nor do you see it in me: but we both see it in the unchangeable truth which is above our minds." Now the unchangeable truth is contained in the eternal types. Therefore the intellectual soul knows all true things in the eternal types.
I answer that, As Augustine says (De Doctr. Christ. ii, 11): "If those who are called philosophers said by chance anything that was true and consistent with our faith, we must claim it from them as from unjust possessors. For some of the doctrines of the heathens are spurious imitations or superstitious inventions, which we must be careful to avoid when we renounce the society of the heathens." Consequently whenever Augustine, who was imbued with the doctrines of the Platonists, found in their teaching anything consistent with faith, he adopted it: and those thing which he found contrary to faith he amended. Now Plato held, as we have said above (Article 4), that the forms of things subsist of themselves apart from matter; and these he called ideas, by participation of which he said that our intellect knows all things: so that just as corporeal matter by participating the idea of a stone becomes a stone, so our intellect, by participating the same idea, has knowledge of a stone. But since it seems contrary to faith that forms of things themselves, outside the things themselves and apart from matter, as the Platonists held, asserting that "per se" life or "per se" wisdom are creative substances, as Dionysius relates (Div. Nom. xi); therefore Augustine (QQ. 83, qu. 46), for the ideas defended by Plato, substituted the types of all creatures existing in the Divine mind, according to which types all things are made in themselves, and are known to the human soul.
When, therefore, the question is asked: Does the human soul know all things in the eternal types? we must reply that one thing is said to be known in another in two ways.
First, as in an object itself known; as one may see in a mirror the images of things reflected therein. In this way the soul, in the present state of life, cannot see all things in the eternal types; but the blessed who see God, and all things in Him, thus know all things in the eternal types.
Secondly, on thing is said to be known in another as in a principle of knowledge: thus we might say that we see in the sun what we see by the sun. And thus we must needs say that the human soul knows all things in the eternal types, since by participation of these types we know all things. For the intellectual light itself which is in us, is nothing else than a participated likeness of the uncreated light, in which are contained the eternal types. Whence it is written (Psalm 4:6-7), "Many say: Who showeth us good things?" which question the Psalmist answers, "The light of Thy countenance, O Lord, is signed upon us," as though he were to say: By the seal of the Divine light in us, all things are made known to us.
But since besides the intellectual light which is in us, intelligible species, which are derived from things, are required in order for us to have knowledge of material things; therefore this same knowledge is not due merely to a participation of the eternal types, as the Platonists held, maintaining that the mere participation of ideas sufficed for knowledge. Wherefore Augustine says (De Trin. iv, 16): "Although the philosophers prove by convincing arguments that all things occur in time according to the eternal types, were they able to see in the eternal types, or to find out from them how many kinds of animals there are and the origin of each? Did they not seek for this information from the story of times and places?"
But that Augustine did not understand all things to be known in their "eternal types" or in the "unchangeable truth," as though the eternal types themselves were seen, is clear from what he says (QQ. 83, qu. 46)--viz. that "not each and every rational soul can be said to be worthy of that vision," namely, of the eternal types, "but only those that are holy and pure," such as the souls of the blessed.
From what has been said the objections are easily solved.
Source: Summa Theologica (New Advent)