On Reconciliation & Penance:

It has been asked what is to be done about those who, after Baptism, have given themselves on every occasion to the pleasures of incontinence, and at the very end of their lives ask for Penance and at the same time the reconciliation of Communion. [6] The former rule in their regard was more difficult, the recent more lenient, because mercy has intervened. For the former custom held that Penance was to be granted but Communion denied. For in times when there were cruel persecutions, lest the ease with which Communion was granted might not restrain men, confident of reconciliation, from a lapse, Communion was rightly denied; but Penance was granted, lest the whole be entirely denied; and by reason of the times, forgiveness was made more difficult. But after our Lord restored peace to His Churches, terror having now been removed, it was decided that Communion should be given the dying, as a Viaticum for those about to set forth, both on account of the mercy of the Lord and lest we seem to be following the harshness and rigor of the Novatianist heretic in refusing forgiveness. With Penance, therefore, a last Communion will be given, so that men of this sort or in their final extremities, our Savior permitting, may be delivered from eternal ruin.” –Letter to Exsuperius, bishop of Toulouse 6,2,5. (A.D. 405)

On Church Authority in Determining Biblical Canon:

“Which books really are received in the canon, this brief addition shows. These therefore are the things of which you desired to be informed. Five books of Moses, that is, Genesis, Exodus, Leviticus, Numbers, and Deuteronomy, and Joshua the son of Nun, and Judges, and the four books of Kings together with Ruth, sixteen books of the Prophets, five books of Solomon, and the Psalms. Also of the historical books, one book of Job, one of Tobit, one of Esther, one of Judith, two of Maccabees, two of Ezra, two of Chronicles. And of the New Testament: of the Gospels four. Epistles of the apostle Paul fourteen. Epistles of John three. Epistles of Peter two. Epistle of Jude. Epistle of James. Acts of the Apostles. John’s Apocalypse. But the rest of the books, which appear under the name of Matthias or of James the Less, or under the name of Peter and John (which were written by a certain Leucius), or under the name of Andrew (which were written by the philosophers Xenocharides and Leonidas), or under the name of Thomas, and whatever others there may be, you should know they are not only to be rejected but also condemned.” –Letter to Exsuperius, bishop of Toulouse. (A.D. 405) B.F. Westcott, A General Survey of the History of the Canon of the New Testament (5th ed. Edinburgh, 1881), pp. 570

On Church Hierarchy & Heresy:

“To presbyters and deacons, and all the clergy and people of the Church of Constantinople, the brethren beloved who are subject to the bishop John (Chrysostom), greetings. . . From the letters of your love which you have sent by the hands of Germanus the presbyter, and Casianus the deacon, I have studied with anxious care the scene of calamity which you have placed before my eyes. . . Not only therefore do we say that these ought not to be followed, but rather that they should be condemned among heretical and schismatic decrees, as was formerly done in the Council of Sardica by the bishops who were before us.” –The Letter of Pope Innocent I to John Chrysostom (Written ca 416 A.D.)

On Church Authority:

“In regards to the observance of the canons we lay it down that we ought to follow those, which were defined at Nicæa, to which alone the Catholic Church is bound to pay obedience and recognition. And if others are brought forward by certain men, which are at variance with the canons framed at Nicæa, and are proved to have been composed by heretics, let them be rejected by the Catholic bishops. For the inventions of heretics ought not to be appended to the Catholic canons. . .”  –The Letter of Pope Innocent I to John Chrysostom (Written ca 416  A.D.)

On Church Councils & Apostolic Tradition:

“In making inquiry with respect to those things that should be treated with all solicitude by bishops, and especially by a true and just and Catholic Council, by preserving, as you have done, the example of ancient tradition, and by being mindful of ecclesiastical discipline, you have truly strengthened the vigour of our Faith, no less now in consulting us than before in passing sentence.”  –Epistle 29, to the Council of Carthage (In requirendis). Jan 27, 417 AD. Patrologia Latina 33.780)

On Papal Authority:

For you decided that it was proper to refer to our judgement, knowing what is due to the Apostolic See, since all we who are set in this place, desire to follow the Apostle (Peter) from whom the very episcopate and whole authority of this name is derived. Following in his steps, we know how to condemn the evil and to approve the good. So also, you have by your sacerdotal office preserved the customs of the Fathers, and have not spurned that which they decreed by a divine and not human sentence, that whatsoever is done, even though it be in distant provinces, should not be ended without being brought to the knowledge of this See, [39] that by its authority the whole just pronouncement should be strengthened, and that from it all other Churches (like waters flowing from their natal source and flowing through the different regions of the world, the pure streams of one incorrupt head), should receive what they ought to enjoin, whom they ought to wash, and whom that water, worthy of pure bodies, should avoid as defiled with uncleansable filth. ” –Epistle 29, to the Council of Carthage (In requirendis). Jan 27, 417 AD. Patrologia Latina 33.780)

On Confirmation & Infant Baptism:

“In regard to the confirming of infants, however, it is clear that it is not permitted to be done by any other than the bishop. For the presbyters, granted they be secondary priests, do not, however, possess the summit of the pontificate. This pontifical power by which they confirm or confer the Spirit, is shown to belong only to bishops, not only by ecclesiastical custom but also by that passage of the Acts of the Apostles which declares that Peter and John were directed to give the Holy Spirit to persons already baptized. For it is permitted presbyters, when they baptize either without a bishop or in the presence of a bishop, to anoint the baptized with chrism, but with chrism which has been consecrated by a bishop; they are not permitted, however, to sign the forehead with that same oil, which signing pertains to bishops only, when they confer the Spirit Paraclete.” -Letter to Decentius, Bishop of Gubbio 25,3,6 (Written March 19, 416 A.D.)