… The self-revelation of the Father in the Word, Truth, is dyadically united with self-revelation in the Spirit of the Truth, the hypostatic Life of Divinity, which properly is the Love of God for Himself in His ousia as Sophia, or for His own being. This third aspect of the self-revelation, not only in knowledge (ideally) but also in life (really), is the living connection (the copula between the subject and the predicate), the life of Divinity in Its Own and in Itself. The Father, as the initial hypostasis, is not only revealed in His Ousia-Sophia through the Son, but also lives in her by the Holy Spirit. And the Son not only reveals the Father through Himself in His Ousia-Sophia, but also lives in her by the Holy Spirit. And this life in reality, Ousia, as the divine reality of the Truth, or Beauty, actualizes in itself the mutual being of the Father for the Son and of the Son for the Father, not only in the statics of ideal self-definition but also in the dynamics of the life of the one hypostasis through the other. But this dynamics of life is, once again, not only a state and in this sense a given of external self-definition, for which there is in general no place in the absolute subject. It is also a hypostasis.

This Life of the Father and of the Son has as its source, naturally, the Initial hypostasis of the Father, Who reveals Himself in the Son. This life exists for the Father hypostatically as the Holy Spirit, Who is not generated but "proceeds" from the Father. This distinction between generation and procession is, according to the general testimony of the Church Fathers, a mystery of the Divine life inaccessible to human comprehension. "Procession" expresses a mode of relation to the Father that is different from the Son's relation to Him. The starting point here too is the self-revelation of the Father, which is realized in the Son, but is not exhausted by this. Rather, it is completed by the procession of the Holy Spirit from the very same Father, from the Father of the Son, and therefore with the Son, in the Son, through the Son.

In other words, the relation of the Holy Spirit to the Father is not only a dyadic one. If it were, the Holy Trinity would then be divided into two parallel dyads: Father-Son and Father-Spirit, which would not be connected and would be united in the Father only by the unity of "origination." One can therefore say that the Father has two different functions: He engenders the Son and He is the Spirator of the Spirit, Who proceeds from Him. There may even arise the question: Is the First hypostasis the Father only in relation to the Son, while being the Spirator in relation to the Spirit, the one from whom the Spirit proceeds? In reality, this relation is a triadic one, because the Holy Spirit is the Life of the Father and of the Son, of the Father in the Son and of the Son in the Father; while for Himself the Holy Spirit is this And (or Is, the copula of the subject and the predicate).

In other words, in His very being, as the ontologically Third hypostasis, not in a dyad but in the Holy Trinity, consubstantial and without separation, the Holy Spirit already presupposes fatherhood and sonhood. This hypostasis completes the self-revelation of the Divine Spirit by definitively overcoming in Him all givenness; not only the content of His self-revelation but also His life acquires a hypostatically transparent character, is a hypostasis. Therefore, a complete adequacy between hypostasis and ousia is achieved; all of God's being is personal as well as natural; there is no extrahypostatic nature and no extranatural hypostatizedness. The subject is exhaustively defined by the predicate; and between them there exists just as exhaustive a connection. Natural being is hypostatized in all these elements. There exist three hypostases, not more and not less; and these are not three abstract hypostases, but the First, Second, and Third, the trihypostatic interrelationship, the Holy Trinity, the Absolute Spirit.

The Third Hypostasis completes the self-revelation of the Divine, Holy Spirit. This hypostasis is in fact the Holy Spirit in the Spirit of God. Among other meanings, this name attests precisely to such a completing significance of the Holy Spirit in the self-revelation of the Divine Spirit. And although, of course, both the Father and the Son are Spirit, inasmuch as God is, in general, Spirit, the Third hypostasis is the Holy Spirit par excellence, as the self-revealing spirituality of the Spirit. The Holy Spirit in the Divine Spirit is the Third hypostasis because, in a certain sense, He is also the Final hypostasis.