Augustine, De Ideis, from 83 Different Questions

46. On Ideas.

1. Plato is said to have been the first to have given the ideas that name. Nevertheless, it is not the case that, if this name did not exist before he introduced it, then the things themselves which he called ideas either were not in existence or were not known by anyone, but rather they were perhaps called by other names by different people.  For it is quite proper for anyone to imposed any name at all upon a [previously] unknown thing which has no [traditional and] customary name.

Indeed, it is unlikely that either there were no wisemen before Plato or that those things which Plato, as was said, called ideas — whatever they be — were not known since the power constituted in these is so great that no one can be wise unless these have been known.  It is also likely that there were wisemen in other nations besides Greece: Plato himself not only bears sufficient witness to this by his journeying for the sake of perfecting his wisdom, but also mentions it in his books.  Therefore, these wisemen, if there were any, should not be thought to have been ignorant of the ideas, although they perhaps called them by another name. But regarding the name, let this much be said: let us regard the thing which is above all to be considered and known in such a way that each person names the thing which he has come to know whatever he wishes, using the words which are in his power.

2. Therefore, we can call the ideas forms or species in a word for word translation. However, if we call them intelligible principles (rationes), we deviate from literal translation. For rationes are called in Greek logoi, not ideas.  But nevertheless whoever wishes to use this word will not stray far from the thing itself.  For the ideas are certain principal forms or fixed and unchangeable formulae (rationes) of things, which are not themselves informed [by other forms] — and because of this both eternal and always unchangeably the same (semper eodem modo sese habentes) — and which are contained in the Divine Intelligence.  Moreover, although these neither come into being nor pass out of being, everything which is able to come into being and pass out of being, and everything which does [in fact] come into being and pass out of being is nevertheless said to be formed in accordance with these.

How they are known.  The soul, however, is said to be unable to see these (eas intueri) unless it be rational, [and then it does so only] by that part of it by which it excels, that is, by mind itself and reason, as if by a certain facing or by its interior and intelligible eye. And this rational soul itself — not every and any [soul] whatsoever but the one which is holy and pure — is asserted to be fit for that vision, that is, the one which will possess that very eye by which those things are seen, an eye healthy, unspoiled, clear and similar to these things which it endeavors to see.

But who [is there], devout and trained in true religion although not yet able to contemplate these things, [who] would nevertheless dare to deny, rather, not even to acknowledge that all existing things — that is, whatever things are contained within their own kind by a certain nature of their own so that they may exist — have been produced by God the Creator, that all that live have life from this Creator and that the universal well-being of things (atque universalem rerum incolumitatem) and the very order by which those subject to change run their temporal courses with sure guidance are encompassed and governed by the laws of the Highest God?

With this established and conceded, who would dare to say that God has created all things without a rational plan (irrationalibiliter)?  But if this cannot rightly be said or believed, then clearly (restat ut) all things have been created in accordance with reason (ratione). [But this does] not [mean] that man was created with the same specific formula (ratione) as the horse, for it is absurd to think [this].

Therefore, individual [species] of things are created with their own specific formulae (propriis rationibus).  And where should these formulae (rationes) be thought to be if not in the mind of the Creator?   For He did not look to anything existing outside Himself so that according to that thing [existing outside Himself] He might constitute what He constituted / created: indeed to hold this opinion is sacrilege.  And if these formulae (rationes) of all things to be created or [already] created are contained in the Divine Mind, and nothing can be in the Divine Mind unless it be eternal and unchanging — and Plato names these primary formulae (rationes) of things ideas — then not only are they ideas, but they are themselves true because they are eternal, and they remain unchangingly the same: whatever exists, in whatever way it exists, comes to exist by the participation of these.

But among all the things created by God, the rational soul surpasses all.  It is near to God when it is pure and, to the extent that it clings to Him in love, it also contemplates those formulae being filled and illuminated by Him in some way with that intellectual light — not through corporeal eyes, but rather through the source of its very self by which it rises high / excels, that is, through its intelligence — and in the vision of these it finds its supreme happiness.

As was said above, it is quite permissible to call these rationes ideas or forms or species or formulae. And, while it is allowed to the many to call them what they will, it is allowed to very few to see the reality.