The Angelic Doctor Against the Errors of the Greeks - Chapter 1

How the Son is understood to be related to the Father as something caused to its cause.

Doubt may trouble some persons on discovering that in many passages of these authorities the Father is said to be the cause of the Son, and the Father and Son the cause of the Holy Spirit. And this occurs first in the words which Athanasius isDoubt may trouble some persons on discovering that in many passages of these authorities the Father is said to be the cause of the Son, and the Father and Son the cause of the Holy Spirit. And this occurs first in the words which Athanasius is reported  to have spoken at the Council of Nicaea: “Whatever the Son has from the Father, he has a word from the heart, as brightness from the sun, a stream from its source, or an effect from its cause. He who insults or denies what is caused quite certainly also denies its cause. The begotten Son who is caused says: He who rejects me rejects Him who sent me” (Lk. 10:16).  Elsewhere Athanasius says: “The Spirit is not unoriginated, that is, without any principle or cause, but rather he shows himself to be true God, originated, however, not in time, but from the cause of true origin.”  And Basil says: “The Holy Spirit, sent by God himself, has a cause.” And Theodoret commenting on the Epistle to the Hebrews says: “The cause of the Son is the Father.” 

Among the Latins,  however, the Father is not usually called the cause of the Son or of the Holy Spirit, but only their principle or origin, for this there are three reasons. reported to have spoken at the Council of Nicaea: “Whatever the Son has from the Father, he has a word from the heart, as brightness from the sun, a stream from its source, or an effect from its cause. He who insults or denies what is caused quite certainly also denies its cause. The begotten Son who is caused says: He who rejects me rejects Him who sent me” (Lk. 10:16).  Elsewhere Athanasius says: “The Spirit is not unoriginated, that is, without any principle or cause, but rather he shows himself to be true God, originated, however, not in time, but from the cause of true origin.”  And Basil says: “The Holy Spirit, sent by God himself, has a cause.”  And Theodoret commenting on the Epistle to the Hebrews says: “The cause of the Son is the Father.” 

Among the Latins,  however, the Father is not usually called the cause of the Son or of the Holy Spirit, but only their principle or origin, for this there are three reasons.

First, because the Father cannot be understood as a cause of the Son in the manner of a formal or material or final cause, but only after that of an originating cause, to wit an efficient cause. But we find that an efficient cause is always diverse in essence from that of which it is the cause. Therefore, to exclude the notion that the Son has an essence diverse from that of the Father, we are not accustomed to speak of the Father as cause of the Son, but prefer to use words connoting origin jointly with consubstantiality, such as fount, head, and the like.

Second, because for us cause and effect are correlative terms. Hence we do not say the Father causes, lest someone take this to mean that the Son was made. And even with the philosophers God is called prime cause; whatever is caused is included by them in the universe of creatures. And so, if the Son could be said to have a cause, he could be understood as being included within the universe of caused beings or creatures.

Third, because when speaking of God man should not lightly depart from the scriptural mode. Sacred Scripture, however, calls the Father the beginning (or principle) of the Word, as is clear from John 1:1. “In the beginning was the Word.”  Nowhere does it say that the Father is a cause or that the Son is caused. Therefore, since cause says more than principle, we do not presume to say that the Father is a cause or the Son is caused.

No word, however, connoting origin is more aptly used when speaking of God than this word principle. Because what is in God is incomprehensible and cannot be defined by us, in speaking of God we more fittingly use general terms rather than proper terms: hence his most proper name is said to be “Who Is”, which is as a term most general, as is evident in Exodus 3:14. And as cause is more general  than element, so principle is more general than cause. Therefore, in speaking of God we very appropriately use the term principle.

This is not to be interpreted, however, as if the aforementioned saints who used such terms as cause and caused meant to imply that the divine persons did not have the same nature, or that the Son was a creature. They wished to indicate merely the origin of the persons, as we do when we use the term principle. Hence Gregory of Nyssa states: “When we say cause and caused, we do not mean by these terms natures. For we do not employ these terms as substitutes for essence or nature; rather we illustrate how precisely Father and Son differ, namely we show how the Son is not begotten of anyone.”  Similarly, Basil says: “Because unbegotten the Holy Spirit, I say, has not a Father; nor is he a creature, because he is not created, but has God as his cause; God of whom he is truly the spirit, and from whom he proceeds.”