Early Trinitarianism

Athanasius of Alexandria (c. 296-373) was the primary opposition to Arius during the Arian controversy. He is the first systematic Trinitarian theologian in my estimation, and thus occupies a unique position in Church history. Athanasius and Hosius of Cordoba (c. 256-359) were the de facto leaders of the Homoousion (ομοούσιον) party and argued that the Son shared the same essence as the Father—while the two remained individual hypostases. There were several analogies used by Athanasius to illustrate his Christology. Often he says that all humanity shares the same essence and yet remains distinct in personhood and individuality. Just as the human family shares the same humanity, God and his Son share the same deity. Later the same kind of language was used in the Chalcedonian Symbol (451), describing Christ as homoousios with us in humanity, but homoousios with the Father in deity. 

"Even this is sufficient to dissuade you from condemning those who have said that the Son was consubstantial with the Father, and yet let us examine the very term consubstantial, in itself, by way of seeing whether we ought to use it at all, and whether it be a proper term, and is suitable to apply to the Son. For you know yourselves, and no one can dispute it, that Like is not predicated of essence, but of habits, and qualities; for in the case of essences we speak, not of likeness, but of identity. Man, for instance, is said to be like man, not in essence, but according to habit and character; for in essence men are of one nature. And again, man is not said to be unlike dog, but to be of different nature. Accordingly while the former are of one nature and coessential, the latter are different in both." (De Synodis 53.)

Note carefully his statement that "in essence men are of one nature," which is to say that all men are consubstantial. St. Paul and Barnabas were consubstantial with respect to their humanity. It ought to be noted that there was no firm distinction between hypostasis and ousia in this period. The Nicenes occasionally spoke of the Father, the Son and the Spirit as three ousiai or three hypostases interchangeably. This is seen even in the 325 creed and the anathema which condemns those “who assert that the Son of God is from a different hypostasis or substance,” η εξ ετέρας υποστάσεως η ουσιάς φάσκοντας είναι, the converse assertion being, that the Son is from the same hypostasis or substance. Which is to say that there was some fluidity between the terms which has usually been lost in modern colloquial discussions. For Athanasius, then, the persons of the Trinity are three beings who share the same generic essence just as three humans might share humanity, Schaff explains,

"The term homoousion, in its strict grammatical sense, differs from monoousion or toutoousion, as well as from heteroousion, and signifies not numerical identity, but equality of essence or community of nature among several beings. It is clearly used thus in the Chalcedonian symbol, where it is said that Christ is "consubstantial (homoousios) with the Father as touching the Godhead, and consubstantial with us (and yet individually, distinct from us) as touching the manhood." (Philip Schaff, History of the Christian Church, Vol. III, p. 130.)

It was not until the Cappadocians that the Trinitarian language becomes more precise. All humans are coessential (ομοούσιος) but they are still numerically distinct beings. This sharing of essence is generic, not necessarily numeric, consubstantialem and not unius substantiae as Hosius would later translate in his later Latin version of the Nicene Creed. Eusebius of Caesarea, who defended Arius and taught a form of Homoian Arianism, signed onto the Nicene Creed because of the vagueness of the term "coessential (ομοούσιος)." He understood the phrase to be "indicative of the Son's being indeed from the Father, yet without being a part of him." (Epistle on the Nicene Council, 5.) Athanasius attempted to avoid the charge of Tritheism by appealing to the Monarchy of the Father, hence in our day this position has come to be known as Monarchical Trinitarianism by modern scholars. This same defense was used by the later Cappadocians, who did not attempt to ground monotheism solely in the unity of the essence, but rather, in the monarchy of God the Father. Therefore, Gregory Nazienzen says,

"Three Infinite Ones, Each God when considered in Himself; as the Father so the Son, as the Son so the Holy Ghost; the Three One God when contemplated together; Each God because Consubstantial; One God because of the Monarchia." (Oration. 40.41.) 

The Son was eternally begotten, and thereby, he participates in divinity because of this relation to the Father, similarly, the Holy Spirit eternally proceeds from the Father. The Father alone was unbegotten or asei, αυτόθεος or αυτοθεότης, and therefore, there was only one God in the strict sense, hence the Nicene Creed begins, "we believe in one God, the Father almighty." Monotheism was grounded primarily upon the monarchy of the Father and only secondarily upon the unity of the divine essence, Athanasius argued,

"Nor again, in confessing three realities and three Persons, of the Father and the Son and the Holy Ghost according to the Scriptures, do we therefore make Gods three; since we acknowledge the Self-complete and Ingenerate and without beginning and Invisible God to be one only, the God and Father of the Only-begotten, who alone has being from Himself, and alone vouchsafes this to all others bountifully." (De Synodis 26.)

On the original Nicene model, the Father is not greater to the Son in nature, or in time, but he is greater inasmuch as Christ is generated from him. This was the standard interpretation of St. John 14:28 given by the ancient Fathers and apologists. Alexander of Alexandria wrote in his epistle on the Arian controversy, "We must say that to the Father alone belongs the property of being unbegotten, for the Savior Himself said, 'My Father is greater than I.'" (Epistles on Arianism, 1.12.)

Alexander says elsewhere, "we have learned; in this alone is He inferior to the Father, that He is not unbegotten." (Ibid.) It is noteworthy that the Nicene Creed of 325 does not even expound  the Holy Spirit as a third divine person. The Spirit is only mentioned in one terse statement, "in the Holy Spirit." It does not say whether the Holy Ghost is a person, whether it proceeds from the Father alone, or whether it is coessential and worthy of worship. The revised Niceno-Constantinopolitan Creed of 381 is careful to articulate the personhood and coessential deity of the Holy Spirit but still did not assert a numerical unity among the persons directly. This was done in the later Ecumenical councils.