37 He ever paid submissive homage to the Church, our supreme teacher through the Roman Pontiffs. Thus, with a view to putting an end to the controversy raging in the East concerning the mystery of the Holy Trinity, he submitted the question to the Roman See for settlement, and wrote from the Syrian desert to Pope Damasus as follows: I decided, therefore, to consult the Chair of Peter and that Roman faith which the Apostle praised; I ask for my soul's food from that city wherein I first put on the garment of Christ. . .I, who follow no other leader save Christ, associate myself with Your Blessedness, in communion, that is, with the Chair of Peter. For I know the Church was built upon that Rock. . . I beg you to settle this dispute. If you desire it I shall not be afraid to say there are Three Hypostases. If it is your wish let them draw up a Symbol of faith subsequent to that of Nicaea, and let us orthodox praise God in the same form of words as the Arians employ.
Source: Spiritus Paraclitus (Vatican.va)