The dogma that the Holy Spirit proceeds from the Father is explained by the fact that even if the Spirit is perceived as a personal, free, and rational entity, his eternal origin has a unique character, distinct from the Son’s conception.

Distinct Origins in the Trinity: Understanding the Procession of the H

The dogma that the Holy Spirit proceeds from the Father is explained by the fact that even if the Spirit is perceived as a personal, free, and rational entity, his eternal origin has a unique character, distinct from the Son’s conception. Unlike the Son, who is begotten of the Father, the Spirit is not "born" but eternally proceeds from the Father; this procession underscores that only the Father is the original source of the Holy Spirit’s hypostasis. As noted in one of the sources, "The Son is begotten of the Father, and the Spirit proceeds from the Father" ( link txt), thereby emphasizing the fundamental difference between the action through which the personal characteristics of the Son and the Spirit are manifested.

Another text indicates that when the Church affirms that the Holy Spirit proceeds from the Father, it thereby emphasizes His eternal, primary origin precisely from the Father, as stated: "The Spirit of Truth, who proceeds from the Father..." (John 15:26). At the same time, the personal properties of the Spirit remain unchanged and essential—He is a free being, acting with self-consciousness, as the author observes that "the personal or hypostatic property of the Holy Spirit is His procession from the Father" ( link txt).

Thus, the distinction between the "birth" of the Son and the "procession" of the Spirit allows for the preservation of both the inner unity and the distinction of the persons within the Trinity: the Spirit maintains His personality, even though His being has its own intrinsic, eternal origin solely from the Father. This avoids any mixing of roles within the Trinity and ensures that, while possessing personal qualities, the Spirit holds his unique place as the immediate flow (procession) of divine life from the source—the Father.

Supporting citation(s):
"The Son is begotten of the Father, and the Spirit proceeds from the Father." (source: link txt)

"Therefore, when the Church concisely expresses that the Holy Spirit proceeds from the Father, it always means the words of Christ: 'The Spirit of Truth, who proceeds from the Father...'" (source: link txt, page: 39)

"The hypostatic property cannot be lost or become the attribute of another Person... Scripture clearly testifies that only the Father is the Source of the Holy Spirit." (source: link txt)