Chapter 13 — That there is only one Son in God

Since God understands all other things by understanding himself, as we proved in the first book; (Cc. 49-50.) and since he understands himself in one simple glance, for his act of understanding is his being, it follows of necessity that there is only one Word of God. And as in God the generation of the Son is nothing else but the conception of the Word, it follows that there is but one generation in God, and but one Son begotten of the Father. Hence it is said: We have beheld his glory, glory as of the only Son from the Father (John 1:14), and again: The only Son, who is in the bosom of the Father, he has made him known (John 1:18).

It would seem, however, to follow from the foregoing that there is yet another word of the divine Word, and another son proceeding from the Son. For we proved that the Word of God is true God: consequently whatever belongs to God belongs to the Word of God. Now God of necessity understands himself: therefore the Word of God also understands himself. If then, because God understands himself, there is in God the Word begotten of him, it would seem to follow that we must ascribe to the Word also yet another word, inasmuch as he understands himself. Thus there will be a word of the Word, and a son of the Son. And this other word, if it be God, will also understand himself, and will have another word, so that there will be an infinite process of divine generations.

This objection may be solved from what has already been said. For while we have proved that the Word of God is God, we have also shown that he is not another God distinct from the God whose Word he is, but is wholly one with him, and distinct only as the Word proceeding from him. Now as the Word is not another God, so neither is he another intellect, nor consequently has he another act of understanding. And yet it does not follow that the Word has his own word by reason of his understanding himself, because, as stated above, the Word is distinct from the speaker solely in that he proceeds from him. Therefore, all other things must be ascribed in common to God who speaks—that is, the Father—and to the Word who is the Son, because the Word also is God. This alone is to be ascribed to the Father exclusively: the Word proceeds from him. And this alone is to be ascribed to the Son exclusively: he proceeds from God speaking.

Hence we gather that the Son is not impotent, though unable to beget a son, while the Father nevertheless does beget a Son. For Father and Son have the same power, even as they have the same divinity. And since in God generation is the intelligible conception of the Word, according as God understands himself, it follows that in God the power of begetting is identical with his power of understanding himself. And since in God the act of understanding himself is one and simple, it follows that also his power of understanding himself, which is identical with his act, is but one. By the same power, therefore, both the Word is conceived and the speaker of the Word conceives; consequently, by the same power the Father begets and the Son is begotten. Therefore, the Father has no power that the Son has not, yet the Father has the generative power for the purpose of begetting, but the Son for the purpose of being begotten. These differ but relatively, as already explained.

Seeing, however, that the Apostle ascribes a word to the Son, from which it would seem to follow that the Son has a son, and that the Word has a word, we must inquire into the meaning of the Apostle when he makes this statement. For he says that God in these last days has spoken to us by a Son (Heb 1:2), and afterwards: He reflects the glory of God and bears the very stamp of his nature, upholding the universe by his word of power (Heb 1:3). Now we must gather the meaning of this passage from what we have been saying. For we said that the concept of wisdom (namely, the word) is rightly called wisdom. We may go yet further so as to see that even the external effect, which results from the concept of wisdom, may itself be called wisdom in the same way as an effect may assume the name of its cause. Thus we call it wisdom not only when a man thinks wisely, but also when he works wisely: therefore, the manifestation of Divine Wisdom in creatures is called the Wisdom of God, according to Sirach: he created her—that is, Wisdom—in the Holy Spirit (Sir 1:9); and afterwards adds: and he poured her out upon all his works (Sir 1:10). Accordingly, the effect of the Word receives the name of word, for even with us the vocal expression of the inward word is called a word, being as it were the word of a word, because it indicates the inward word. Therefore, not only is the concept of the divine intellect called the Word, which is the Son, but also the revelation of the divine concept in visible works is called the Word’s word. In this way are we to understand that the Son upholds the universe by his word of power (Heb 1:3), as also the passage in the Psalm*:* Fire and hail, snow and frost, stormy wind fulfilling his word (Ps 148:8); namely, because the effects of the divine concept are accomplished in the world by created forces.

Now, since God understands all other things in understanding himself, as stated above, it follows that the Word conceived in God through his understanding himself is the only word expressing all things. Yet he is not the Word of God in the same way as of other things, because he is the Word of God as proceeding from God, whereas he is the word of other things not as proceeding from them (because God does not acquire knowledge from things), but rather brings things into being by his knowledge, (Bk. 2, ch. 24.) as we have proved above. Consequently, the Word of God must be the perfect type of all the things that have been made. In what way he can be the proper type of each single thing is plain from our treatise in the first book, (Ch. 65.) where it was shown that God has proper knowledge of all things.

Now whoever makes a thing with intelligence works by means of the idea which he has of that thing as made: thus the material house is made by the builder from the idea of a house that is in his mind. And we have shown above that God brings things into being not by natural necessity, but as an intellectual and voluntary agent. Therefore, God made all things by his Word, who is the type of things made by him. Hence it is said: All things were made through him (John 1:3); also in accord with this, Moses in his account of the creation uses such expressions of each of the works as: God said: ‘Let there be light,’ and there was light (Gen 1:3); and: God said: ‘Let there be a firmament’ (Gen 1:6), and so on. All this is expressed in the words of the Psalmist: He spoke, and they were made (Ps 148:5). For to speak is to utter a word. Accordingly, the statement that God spoke, and they were made means that he spoke the Word, by whom he brought things into being as by the perfect idea of them.

And since the same cause conserves and brings things into being, as all things were made by the Word, so are they conserved in being by God’s Word. Therefore, the Psalmist says: By the word of the Lord the heavens were made (Ps 33[32]:6), and the Apostle says that the Son upholds the universe by his word of power (Heb 1:3). We have already stated how this is to be understood.

There is, however, a difference to be noted between the Word of God and the idea in the mind of the craftsman. The Word of God is God subsistent, whereas the craftsman’s idea of his handiwork is not a subsistent thing, but merely an intelligible form. Now a non-subsistent form is not, properly speaking, competent to act (since to act belongs to that which is perfect and subsistent), but is competent to be acted by, since it is a principle of action whereby the agents act. Hence the craftsman’s idea of the house does not make the house, but the craftsman makes the house by it. On the other hand, since God’s Word, who is the idea of things made by God, is subsistent, he acts and is not merely something acted by. Therefore, the Wisdom of God says: I was with him forming all things (Prov 8:30), and our Lord said: My Father is working still, and I am working (John 5:17).

It must also be observed that the thing made with the intelligence preexists in the mind even before it exists in itself: thus the house exists in the builder’s mind before it is actually built. Now, the Word of God is the type of all things made by God, as we have proved. Therefore, all things made by God must have preexisted in the Word of God before existing in their own nature. Now, the mode of existence of that which is in another follows the mode of that in which it is, and not its own mode: thus the house in the mind of the builder has an ideal and immaterial existence. Hence things must have preexisted in the Word of God according to the mode of the Word. And the mode of the Word is that he is one, simple, immaterial; and not merely living, but life itself, since he is his own being. Consequently, things made by God preexisted in the Word from eternity, in a mode wholly devoid of matter and composition, since in him they were nothing else but the Word himself who is life. Hence it is said: That which was made was life in him (John 1:3–4), namely, in the Word.

Now, as he who works by intelligence and the idea that is in him brings things into being, so too the teacher, by the knowledge that is in him, produces knowledge in his disciple, for the disciple’s knowledge is drawn from the knowledge of his teacher as a copy of it. Now, God by his intelligence is the cause not only of all things that subsist in nature, but also of all intellectual knowledge, as proved above. (Bk. 3, ch. 76.) It follows, therefore, that the Word of God, who is the idea of the divine intellect, must be the cause of all intellectual knowledge. Hence it is said: The life was the light of men (John 1:4), because like a light the Word, who is life, and in whom all things are life, reveals the truth to men. Nor is it the fault of the Word that all men do not attain to the knowledge of the truth, but some remain in the dark. This is due to the fault of men who are not converted to the Word, and are unable to comprehend him fully: therefore, darkness remains in them more or less according as they are more or less converted to the Word and comprehend him. Hence John, in order to remove all deficiency from the Word’s manifestive power, after saying that he is the light of men (John 1:4), adds that the light shines in the darkness, and the darkness has not overcome it (John 1:5), because darkness is due not to the light not shining, but to the fact that some do not comprehend the light of the Word. Even so when the material sun is shining throughout the world, there is no darkness, save to one whose eyes are shut or weak.

This, then, is what to some extent we are able to learn from Sacred Scripture concerning the divine generation and power of the only-begotten Son of God.