On the Christian Faith (De fide)

⁹⁰ What room here, then, for one to sit in judgment upon the Godhead, to call in question the Father and the Son—the One for begetting, the Other for not begetting. No man condemns his servant or handmaid for begetting (or bearing) offspring; but those Arians condemn Christ for not begetting— they do condemn Him, for they privately pass sentence of condemnation upon Him, when they take from His glory and dignity. The question, why they have not begotten offspring, does not lead those who are joined in marriage into loss of their love, or denial of each other's merits, but the Arians, because Christ has not begotten a Son, make light of His sovereignty.

91. Why, ask they, is the Son not a Father? Because, on the other side, the Father is not a Son. Why has not Christ begotten? Even because the Father is not begotten. Yet the Son stands none the lower, because He is not a Father; nor the Father, because He is not a Son, for the Son said: “All things that the Father has are Mine” — so truly is generation involved in the Father's personal attributes, and comes not by mere right of sovereignty.

92. The Substance of the Trinity is, so to say, a common Essence in that which is distinct, an incomprehensible, ineffable Substance. We hold the distinction, not the confusion of Father, Son, and Holy Spirit; a distinction without separation; a distinction without plurality; and thus we believe in Father, Son, and Holy Spirit as each existing from and to eternity in this divine and wonderful Mystery: not in two Fathers, nor in two Sons, nor in two Spirits. For “there is one God, the Father, of Whom are all things, and we in Him; and one Lord, Jesus Christ, by Whom are all things, and we by Him.” There is One born of the Father, the Lord Jesus, and therefore He is the Only-begotten. “There is also One Holy Spirit,” as the same Apostle has said. So we believe, so we read, so we hold. We know the fact of distinction, we know nothing of the hidden mysteries; we pry not into the causes, but keep the outward signs vouchsafed unto us.

93. O monstrous wickedness, that they who have no power over their own procreation should claim and usurp power to enquire into the Divine Generation! Let them deny, them, that the Son is equal to the Father, forasmuch as He has not begotten; let them deny that the Son is equal to the Father, because He has a Father! But if they talked after this fashion about men, who sometimes desire to beget sons, yet cannot, we should call it an insult, just as we should so call it, if of two men, one having sons and the other childless, the latter were said to be inferior to the former on that ground. So monstrous also, I say, does it seem, in regard simply to men, that one should therefore be esteemed the more lightly because he has a father. Peradventure, indeed, the Arians suppose that Christ is in the position of one in a family, and frets because He is not set free and independent of His Father's authority, and is not empowered to administer the estate. But Christ is not under tutelage; nay, rather has He abolished all tutelage.

94. How then, let them tell us, would they have these things to be?— a true generation, the true Son begotten of God the Father, that is, of the Substance of the Father, or of another substance? If they say “begotten of the Father, that is, of the Substance of God,” well and good, for then they acknowledge the Son as begotten of the Substance of the Father. If, then, they are of one Substance, surely they are also of one sovereign Power. Whereas, if the Son is begotten of another substance, how can the Father be Almighty, and the Son not Almighty? For what advantage has God, if He have made His Son of another substance, when confessedly the Son, on His part, has of another substance made us sons of God? The Son, therefore, is either of one Substance with the Father, or of one sovereign Power.

95. Our adversaries' question, then, falls flat, because they cannot judge Christ— or rather, because He is clear, when He is judged. They are worthy, however, to be condemned upon their own sentence, who raise this question against us, for if the Son be therefore not equal to the Father, because He has not begotten a Son, then by all means let them who sow discussions of this kind confess, if they have not children, that their very servants are to be preferred before themselves, inasmuch as they cannot be the equals of those who have children— whereas, if they have children, let them regard the merit thereof as due not to themselves, but of right to their sons.

96. The objection, then, holds not together, that the Son cannot be equal to the Father, by reason of the Father having begotten the Son, while the Son has begotten no Son of Himself, for the spring begets the stream, though the stream begets no spring out of itself, and light begets radiance, and not radiance light, yet the nature of radiance and light is one.