St. Photios the Great ca. 810-893
Leo the Great, whilst bishop of [Old] Rome, carefully demonstrated divine matters in his inspired and dogmatic Tome. In this, he was confirmed by the Fourth Synod. He confirmed its decree, and was praised by the sacred, and God-inspired assembly. He…thus radiates the very same light of Orthodoxy, not only upon the entire West, but also to the ends of the East through his God-inspired and dogmatic epistles, through the legates who exercised his authority, and through the peace with which he illumined that great assembly collected by God. Moreover, he also said that if anyone set up or teach another doctrine other than that taught by the Synod, that person should be deposed if he were of the dignity of the priesthood or anathematized if he were a layperson or even a monastic, religious or ascetic. Whatever that God-inspired Synod decreed, Leo, similarly inspired by God, openly confirmed through the holy men Paschasinus, Lucentius and Boniface (as one may hear many times from them, indeed not only from them, but from him who sent them). Dispatching synodical letters, Leo himself testifies and confirms that the speeches, spirit, and decisions of his delegates are not theirs, but his own. Still, even if there were nothing of this, it is sufficient that they were his representatives at the Synod and that when the Synod ended, he professed to abide by its decisions. (Mystagogy, 79)
