Summa contra Gentiles1.53 Chapter LIII. Solution of the foregoing doubt

The foregoing doubt may be easily solved if we examine carefully how things understood are in the understanding. And in order that, as far as possible, we may proceed from our intellect to the knowledge of the divine intellect, it must be observed that the external objects which we understand do not exist in our intellect according to their own nature, but it is necessary that our intellect contain their species whereby it becomes intellect in act. And being in act by this species as by its proper form, it understands the object itself. And yet the act of understanding is not an act passing into the intellect, as heating passes into the object heated, but it remains in the one who understands: although it bears a relation to the object understood, for the very reason that the aforesaid species, which is the formal principle of intellectual operation, is the image of that object.

It must furthermore be observed that the intellect informed by the species of the object, by understanding produces in itself a kind of intention of the object understood, which intention reflects the nature of that object and is expressed in the definition thereof. This indeed is necessary: since the intellect understands indifferently a thing absent or present, and in this point agrees with the imagination: yet the intellect has this besides, that it understands a thing as separate from material conditions, without which it does not exist in reality; and this is impossible unless the intellect forms for itself the aforesaid intention.

Now this understood intention, since it is the term, so to speak, of the intellectual operation, is distinct from the intelligible species which makes the intellect in act, and which we must look upon as the principle of the intellectual operation; albeit each is an image of the object understood: since it is because the intelligible species, which is the form of the intellect and the principle of understanding, is the image of. the external object, that the intellect in consequence forms an intention like that object: for such as a thing is, such is the effect of its operation. And since the understood intention is like a particular thing, it follows that the intellect by forming this intention understands that thing. On the other hand the divine intellect understands by no species other than His essence, as we have proved. And yet His essence is the likeness of all things. 1 Ch. xlvi. 2 Ch. xxix.

Wherefore it follows from this that the concept of the divine intellect, according as He understands Himself, which concept is His Word, is the likeness not only of God Himself understood, but also of all things of which the divine essence is the likeness. Accordingly many things can be understood by God, by one intelligible species which is the divine essence, and by one understood intention which is the divine Word.