The Principatus of the Father is a great Catholic truth, and was taught in the Church after the Nicene Council as well as before it; but on the other hand, it might easily be perverted into a shape favourable to Semi-Arianism. This danger is so obvious, that I shall have chiefly to employ myself in this Section in defending the doctrine, not in showing its capability of perversion. Let us consider the place it holds in the Catholic system.
No subject was more constantly and directly before the Christian intellect in the first centuries of the Church than the doctrine of the Monarchia 1.That there was but one First Principle of all things was a fundamental doctrine of all Catholics, orthodox and heterodox alike; and it was the starting-point of heterodox as well as of orthodox speculation. To the orthodox believer, however, it brought with it a perplexity, which it did not occasion to the adherents of those shallow systems which led to heresy. Christianity began its teaching by denouncing polytheism as absurd and wicked; but the retort on the part of the polytheist was obvious:—Christianity taught a Divine Trinity: how was this consistent with its profession of a Monarchy? on the other hand, if there was a Divine Monarchia, how was not Sabellius right in denying the distinction of Persons in the Divine Essence? or, if not Sabellius, then Arius, who degraded Son and Spirit to the condition of creatures? Polytheists, Sabellians, Arians, it might be objected, had more to say for themselves in this matter than Catholics.
Catholic theologians met this difficulty, both before and after the Nicene Council, by insisting on the unity of origin, which they taught as existing in the Divine Triad, the Son and Spirit having a communicated divinity from the Father, and a personal unity with Him; the Three Persons being internal to the Divine Essence, unlike the polytheism of the Greeks and Romans, the tritheism of Marcion and the Manichees, and the Archical Hypostases of Plotinus. Thus Hippolytus says: “I say, ‘Another,’ not two Gods, but as light from light, as water from a spring, or a ray from the sun.” And Hilary, in the fourth century, confirms him, saying, “The Father does not lose His attribute of being the One God, because the Son also is God, for the Son is God from God, One from One, therefore One God, because God from Himself.” De Trin. iv. 15. And Athanasius, “We preserve One Origin of Divinity, and not two Origins, whence there is properly a Monarchy.” Orat. iv. 1.
It was for the same reason that the Father was called God absolutely, while the Second and Third Persons were designated by Their personal names of “the Son,” or “the Word,” and “the Holy Ghost;” viz. because they are to be regarded, not as separated from, but as inherent in the Father.
In this enunciation of the august Mystery they were supported by the usage of Scripture, and by the nature of the case; since the very notion of a Father carries with it a claim to priority and precedence in the order of our ideas, even when in no other respect he has any superiority over those on whom he has this claim. There is One God then, they would say, “not only because the Three Persons are in one usia, or substance (though this reason is good too), but because the Second and Third stand to the First in the relation of derivation, and therefore are included in their Origin as soon as named; so that, in confessing One Father or Origin, we are not omitting, but including, those Persons whom the very name of the One Father or Origin necessarily implies.” At the same time it is plain, that this method of viewing the Unity as centered in its Origin, and the Monarchia as equivalent to the Monas, might be perverted into a Semi-Arian denial of the proper divinity of Son and Spirit, if ever They were supposed, by reason of Their derivation, to be emanations, and therefore external to the Essence of the Father.
Nor is this all that has to be said upon this point. St. John translates our Lord’s words (for the vernacular in which He spoke can only be conjectured), “I and the Father are one,” by the neuter “Unum;” and he himself, if the passage be his, says: “These Three are one (unum).” In like manner Tertullian says: “They are all one (unum), by unity of substance.” Other Fathers say the same. But this use of the neuter had this inconvenience, that it seemed to imply a fourth reality in the Divine Being, over and above the Three Persons, of which the Three Persons partook; as if the Divine Unity were a physical whole; or, if not that, a logical species, which implies Tritheism. This is what the Antiochene Fathers, in the case of Paulus, seem to have feared would follow from the use of the word homoüsion, which in consequence they put aside; and we may understand their feeling on the subject, from the harshness with which Eusebius’s statement falls upon the ear, when, in the passage quoted above, p. 157, he speaks of the Triad as attached or belonging to ([exertemene]) One Divine Nature.