Chapter 43 — That in God the Word differs from the Father neither in time, nor in species, nor in nature

Among things that are not different in essence, there can be no difference according to time, species, or nature. Therefore, since the Word is consubstantial with the Father, he cannot differ from the Father in any of these respects.

There can be no difference according to time. For the divine Word is present in God because God understands himself by conceiving his intelligible Word. Hence, it is necessary that if at any time there were no Word of God, during that time God would not understand himself. But God always understood himself during his whole existence, for his understanding is his existence. Therefore, his Word also existed always. And so in the rule of the Catholic faith we say that the Son of God is born of the Father before all ages.

According to species, too, it is impossible for the Word of God to differ from God, as though he were inferior; for God does not understand himself as less than he is. The Word has a perfect likeness to the Father, because that of which he is the Word is perfectly understood. Therefore, the Word of God must be absolutely perfect according to the species of divinity.

Some beings, it is true, that proceed from others are found not to inherit the perfect species of those from whom they proceed. One way in which this can happen is in equivocal generations: for the sun does not generate a sun, but an animal of some kind. To exclude imperfection of this sort from divine generation, we confess that the Word is born God from God.

What is generated or proceeds from another can fall short of it in another way due to a defect in purity, namely, when from what is simple and pure in itself something proceeds through an application to extraneous matter, and so turns out to be inferior to the original species. Thus, from a house that is in the architect’s mind, a house is fashioned in various materials; and from light received in the surface of a body, color results; and from fire, by adding other elements, a mixed body arises; and from a beam of light, by interposing an opaque body, a shadow is caused. To exclude any imperfection of this kind from divine generation, we add: Light from Light.

In yet a third way, what proceeds from another can fail to equal the latter’s species due to a deficiency in truth. That is, it does not truly receive the nature of its original, but only a certain likeness thereof: for example, the image of a man in a mirror or in a picture or in a statue, or even the likeness of a thing in the intellect or in one of our senses. For the image of a man is not said to be a true man, but is a likeness of a man; and a stone is not in the soul, as the Philosopher notes, but a likeness of the stone. To exclude this from the divine generation, we add: true God from true God.

Lastly, it is impossible for the Word to differ from God according to nature, since it is natural for God to understand himself. Every intellect has some things which it naturally understands, as our intellect naturally understands first principles. Much more does God, whose act of understanding is his existence, naturally understand himself. Therefore, his Word proceeds from him naturally, not in the way that things proceed otherwise than by natural origin; that is, not in the way that the artificial objects we are said to make proceed from us. What proceeds from us naturally, such as a son, we are said to generate. Accordingly, lest it be thought that the Word of God proceeds by the power of his will and not naturally, the phrase is added: begotten, not made.