VATICAN CITY, AUG. 30, 2007 (Zenit) - Here is a translation of the address Benedict XVI delivered today at the general audience in St. Peter's Square. The reflection focused on St. Gregory of Nyssa.

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Dear Brothers and Sisters!

In the last few catecheses I spoke about two great doctors of the Church of the fourth century, Basil and Gregory Nazianzen, bishop of Cappadocia, in present-day Turkey. Today we add a third, Basil's brother, St. Gregory of Nyssa, who showed himself to be a man of meditative character, with a great capacity for reflection, and a vivacious intellect, open to the culture of his time. He showed himself in this way to be an original and deep thinker in Christian history.

Born in 335, his Christian formation was carried out largely by his brother Basil -- whom he defined as "father and teacher" (Ep 13,4: SC 363, 198) -- and by his sister Macrina. He completed his studies, with a particular appreciation for philosophy and rhetoric. At the beginning, he dedicated himself to teaching and got married. Then he too, like his brother and sister, dedicated himself entirely to the aesthetic life. Later he was elected bishop of Nyssa, and showed himself to be a zealous pastor, earning the esteem of the community. Accused of economic embezzlements by heretical adversaries, he had to abandon his episcopal see for a brief time, but then made a triumphant return (cf. Ep. 6: SC 363, 164-170), and continued to commit himself to the defense of the true faith.

Especially after Basil's death, almost garnering his spiritual legacy, Gregory cooperated in the triumph of orthodoxy. He participated in various synods; he tried to settle divisions between the Churches; he took an active part in the Church's reorganization; and, as "a pillar of orthodoxy," he was a protagonist at the Council of Constantinople in 381, which defined the divinity of the Holy Spirit. He received various official appointments from Emperor Theodosius, he gave important homilies and eulogies, and dedicated himself to writing various theological works. In 394, he participated yet again in a synod held in Constantinople. The date of his death is unknown.

Gregory expresses with clarity the scope of his studies, the supreme goal for which he aims in his theological work: to not engage one's life in vane pursuits, but to find the light that enables one to discern that which is truly useful (cf. "In Ecclesiasten Hom" 1: SC 416, 106-146).

He found this supreme good in Christianity, thanks to which "imitation of the divine nature" is possible ("De Professione Christiana": PG 46, 244C). With his acute intelligence and his vast knowledge of philosophy and theology, he defended the Christian faith against heretics, who negated the divinity of the Son and the Holy Spirit (like Eunomios and the Macedonians), or negated Christ's perfect humanity (like Apollinaris).

He commented on sacred Scripture, concentrating on the creation of man. For him the essential theme was creation. He saw the reflection of the Creator in the creature and therein found the path to God. But he also wrote an important book on the life of Moses, which shows him as a man on the path toward God. This hill leading to Mt. Sinai becomes for him an image of our own hill in human life toward true life, toward the meeting with God. He also interpreted the Lord's prayer, the Our Father, and the beatitudes. In his "Great Catechetical Discourse" ("Oratio Catechetica Magna") he laid out the fundamental points of theology, not for an academic theology closed in on itself, but to offer catechists a system of reference to keep in mind in their teaching, a sort of framework within which a pedagogic interpretation of the faith could move.

Gregory is also outstanding because of his spiritual doctrine. His theology was not an academic reflection, but an expression of a spiritual life, of a lived life of faith. His reputation as a "father of mysticism" can be seen in various treatises -- like "De Professione Christiana" and "De Perfectione Christiana" -- the path that Christians must take to reach true life, perfection. He exalted consecrated virginity ("De Virginitate"), and likewise offered his sister Macrina as an outstanding model of life, who remained a guide for him always, an example (cf. "Vita Macrinae").

He gave various discourses and homilies, and wrote numerous letters. In commenting on the creation of man, Gregory highlights the fact that God, "the best artist, forges our nature so as to make it suitable for the exercise of royalty. Through the superiority given by the soul, and through the very make-up of the body, he arranges things in such a way that man is truly fit for regal power" ("De Hominis Opificio" 4: PG 44, 136B).

But we see how man, in the web of sins, often abusive of creation, does not act in a ...