Council of Toledo XI, 675

Trinity. In the relative names of persons, however, the Father refers to the Son, the Son to the Father, and the Holy Spirit to both, in that while relatively three persons are asserted, we yet believe they are one nature or substance. Neither as three persons, so do we predicate three substances, but one substance, however three persons. For, as He is Father, not to Himself, but to the Son; and as He is Son not to Himself but to the Father, similarly also the Holy Spirit refers in a relative sense not to Himself, but to the Father and to the Son, in that He is proclaimed the Spirit of the Father and the Son.

279. Likewise when we say “God,” no relationship is expressed, as the Father to the Son, or the Son to the Father, or the Holy Ghost to the Father and the Son, but God applies especially to Himself. For, if we are asked concerning the individual persons, we must confess that each is God. Therefore, we say that the Father is God, the Son is God, and the Holy Spirit is God each singly; yet there are not three Gods, but there is one God. Likewise also we say that the Father is omnipotent, the Son is omnipotent, and the Holy Spirit is omnipotent, each singly; not, however, three omnipotent Gods, but one omnipotent God, as also we predicate one light and one principle. We confess and believe, therefore, that singly each person is wholly God and that all three persons are one God; they have one indivisible and equal Godhead, majesty or power, neither is it lessened in the single person, nor increased in the three persons, because it does not have anything less when each person of God is spoken of singly,

280. nor more when all three persons are called one God.—Therefore, this Holy Trinity, which is the one and true God, neither excludes number nor is it contained in number.—For in the relation of persons number appears, but in the substance of divinity, what might be enumerated is not understood. Therefore, in this alone they imply number, that they are related to each other; and in this, that they are to themselves, they lack number. For natural unity is so suitable to this Holy Trinity that there cannot be a plurality in the three persons. For this reason, then, we believe that saying in Sacred Scripture: “Great is our Lord and great is his power; and of his Wisdom there is no number” [Ps. 146:5]. Neither because we have said that these three persons are one God, are we able to say that the same one is the Father who is the Son, or that He is the Son who is the Father, or that He who is the Holy Spirit is either the Father or the Son. For He is not the Father who is the Son, nor is He the Son who is the Father, nor is the Holy Spirit He who is either the Father or the Son, even though the Father is the same as the Son, the Son the same as the Father, the Father and the Son the same as the Holy Spirit; that is, in nature one God. For, when we say that the same one is not the Father as the Son, we refer to the distinction of persons. When, however, we say that the Father is the same