Augustine in His Own Words (continued)
material spring or river or drinking water. In these instances, the water from the spring now flows out into the river and has no fixed resting place; when it flows from the river or the spring and becomes drinking water, it does not remain in the same place where it is drawn from. In this way it is possible for water to be labeled now as "spring," now as "river," now as "drinking water." But we have stated that in the Trinity it is impossible for the Father to be at any time the Son, or for the Son to be at any time the Father. . . . These material illustrations have been given, not because of a similarity to that divine nature, but because of a oneness that is discernible even in sense objects. In this way we are able to see how three objects can have, not only individually but even simultaneously, one single name. Nor should anyone think it strange or absurd that we call the Father "God," the Son "God," and the Holy Spirit "God," yet say that in this Trinity there are not three gods but one God and one Substance.25
Equality of Father and Son
Here Augustine takes on the question of the equality of the Father and Son. The passage is interesting because it illustrates Augustine's awareness of favorite prooftexts used by Homoians to argue for the inequality of the Father and Son. Augustine, like other pro Nicenes, insists on the "absolute equality" of Father and Son. Yet he does acknowledge one element of subordination: the Father is the source of the Son's existence and, paradoxically, of the Son's equality with the Father. From On Faith and the Creed:
(9.18) Learned and religious men have dealt with the subject of the Father and the Son in numerous books. As far as humanly possible, they have tried to show in these writings how the Father and the Son are not one Person (unus), but one reality (unum), and tried to work out what is proper to the Father and what is proper to the Son; how the Father is the Begetter, and the Son, the Begotten; how the Father is not from the Son, but the Son is from the Father; how the Father is the origin (principium) of the Son, for which reason He is also called the "Head of Christ" (1 Cor 11:3); but Christ, too, is called the beginning (principium), but not of the Father; the Son is called the Father's Image (Col 1:5), though He differs in no respect and enjoys absolute equality. These matters are treated at greater length by those who do not aim at presenting so brief an exposition of the whole Christian faith as I do.
25. De fide et symbolo 9.16–9.17 (CSEL 41:18–19); my trans., based on Russell, FOTC 27:331–34. Gregory of Nazianzus, in his fifth Theological Oration (Oratio 31.31; SC 250:338), delivered just a little more than a decade earlier, expresses a similar uneasiness with the analogy.