The Petrine Theology

In his sermons — above all those preached on the anniversary of his own consecration and on the feast of the Apostles Peter and Paul — Pope Leo I set out the most developed doctrine of the Roman primacy of the patristic age: Christ’s commission to Peter as the rock (Tu es Petrus), Peter’s enduring principalitas, and the pope as the heres beati Petri, the “heir of blessed Peter,” through whom Peter himself still governs his see. This file — governed by Methodology §4 — presents Leo’s theology as his own genuine teaching, then sets side by side the divergent readings it has received: the Roman reading of a jurisdictional primacy by divine right, and the Orthodox reading of a primacy of honour within a synodal Church in which every bishop sits on Peter’s chair. Both are sourced; the jurisdictional reading is reported accurately as what it is — a later development the Orthodox Church has examined and not received.

Tradition: Pan-Orthodox (Church Father / Latin)

The Sermons and Their Setting

Leo’s doctrine of Peter is not found in a single treatise but is worked out across his preaching, and its native setting is liturgical. The richest texts are the anniversary-of-consecration sermons (Sermones in natali ipsius), preached each year on the day Leo was raised to the see of Rome — Sermons 2, 3, 4, and 5 — and the sermons on the feast of the Apostles Peter and Paul (29 June), Sermons 82 and 83 (Leo, Sermones; PL 54; trans. Feltoe, NPNF 2nd ser., vol. 12). That the theology is preached on his own anniversary is itself part of the argument: Leo reads his elevation not as the start of a new tenure but as a fresh manifestation of Peter’s continuing presence in the Roman see. The doctrine is therefore doxological before it is juridical — it is offered as a confession of what the day means — and only on that basis does it become the most articulate claim to Roman primacy the early Church produced.

Tu Es Petrus: Peter the Rock

The foundation is the dominical word of Matthew 16:18–19. Leo takes Christ’s “You are Peter (Petrus), and upon this rock (petra) I will build my Church,” together with the gift of the keys and the power of binding and loosing, as a commission given to Peter personally and pre-eminently:

“You are Peter, and upon this rock will I build My Church, and the gates of hell shall not prevail against it: and I will give to you the keys of the kingdom of heaven” (Matt 16:18–19, in Leo, Sermon 3.2; trans. Feltoe, NPNF 2nd ser., vol. 12).

For Leo the rock is Christ, but the name Petrus is given to Simon so that the apostle shares, by participation, in the stability that is Christ’s own: Peter is made “rock” because he is joined to the Rock. The strength (firmitas, soliditas) Peter receives is not his by nature but is “poured over” onto him — and, crucially for Leo, onto those who hold his seat after him (Leo, Sermon 3.2–3; Sermon 4.2; trans. Feltoe). The keys are real and the power to bind and loose is real, and they are entrusted in a singular way to one.

Principalitas: Given to One for All

Leo holds together two claims that he is careful never to let fall apart: the apostolic authority is given to all the apostles, yet it is entrusted in a special way to one. This is the doctrine of Peter’s principalitas — his pre-eminence or headship.

“The authority vested in this power passed also to the other apostles… but it is not without good reason that what is bestowed on all is entrusted to one. For Peter received it separately because he is the prototype set before all the rulers of the Church” (Leo, Sermon 4.2–3; PL 54:149–151; trans. Feltoe, NPNF 2nd ser., vol. 12).

The episcopate is one and shared, but Peter is its principle and pattern — the forma, the source from which the others’ authority is, as it were, distributed. The Church is built on all the apostles, but it is built on them through Peter; the unity of the many bishops is referred to the one seat. In Leo’s compressed formula, “the care of the universal Church should converge towards Peter’s one seat, and nothing anywhere should be separated from its head” (Leo, Sermon 4.4; trans. Feltoe). This principalitas is the conceptual bridge from Peter the apostle to the Roman bishop.

Heres Beati Petri: The Heir of Blessed Peter

The bridge is crossed by Leo’s central and most distinctive idea: the heir (heres). Peter does not merely have successors who hold his office; Peter himself lives and judges and presides in his see, and the bishop of Rome acts as his heir — receiving, but never owning, what is Peter’s. Leo presses the point to the edge of paradox by calling himself the unworthy or undeserving heir:

“the blessed Peter persevering in the strength of the Rock which he received does not abandon the helm of the Church which he undertook… and if anything is rightly done and rightly decreed by us… it is of his work and merits whose power lives and whose authority prevails in his See” (Leo, Sermon 3.3; trans. Feltoe).

Leo speaks of himself as the heir who must not, “even in so unworthy an heir,” cause the see to grow lukewarm in its love for “so great a shepherd” (Leo, Sermon 3.4; Sermon 2.2; trans. Feltoe).

The structure is exact: whatever authority Leo exercises is Peter’s, exercised through him; the dignity is the apostle’s, the heir merely its present bearer. This is why, in the matter of Canon 28, Leo could annul a conciliar act “by the authority of blessed Peter” rather than in his own name (see Leo and Canon 28). It is also why his sermons on Peter and Paul can say that Rome was made the “head of the world” more truly through Peter’s holy See than through the empire — the city’s true greatness is apostolic, not imperial (Leo, Sermon 82.1, 3; PL 54; trans. Feltoe). That precise inversion — apostolic over imperial — is the theological engine behind his rejection of the imperial-city rationale of Canon 28.

The Most Developed Patristic Doctrine of Roman Primacy

Scholars across the traditions agree on one point: Leo’s is the most fully developed doctrine of Roman primacy in the patristic era. He gathered the scattered materials of earlier Roman self-understanding — the Petrine texts, the language of the cathedra Petri, the Roman appeal to Nicaea — and forged them into a coherent theology in which the living Peter governs the universal Church through the Roman bishop. Whatever one makes of its truth, its historical primacy as a doctrine is not in dispute (Ullmann, Gelasius I, and A Short History of the Papacy in the Middle Ages, 5–30; Wessel, Leo the Great and the Spiritual Rebuilding of a Universal Rome, 285–321; Meyendorff, Imperial Unity and Christian Divisions, 148–152). What is in dispute is what kind of authority this theology actually establishes — and here the readings part.

The Roman Reading: Jurisdictional Primacy by Divine Right

On the Roman Catholic reading, Leo articulates a primacy that is jurisdictional and held by divine right (iure divino). The commission to Peter in Matthew 16 conferred a real governing authority over the whole Church; that authority passes by succession to the bishops of Rome; and Leo’s language of the principalitas and the heres expresses exactly the office the First Vatican Council (1870) would later define — a universal and immediate jurisdiction, not merely a primacy of honour. Leo’s acts confirm the theory: his confirmation of Chalcedon’s faith, his annulment of Canon 28, his interventions in Gaul and Illyricum, all show a Roman bishop exercising the office his sermons describe. On this reading Leo is the patristic witness par excellence to the Catholic doctrine of the papacy (Vatican I, Pastor Aeternus, 1870; Ullmann, A Short History of the Papacy, 20–30; Wessel, Leo the Great, 285–321; Catholic Encyclopedia, “Pope St. Leo I”).

The Orthodox Reading: Primacy of Honour in a Synodal Church

On the Orthodox reading, Leo’s preaching is received as a genuine and lofty witness to the honour of the see of Rome and the dignity of Peter, but not as evidence of a universal jurisdiction by divine right. Several distinctions carry the reading.

First, the Orthodox tradition holds that every bishop sits on the chair of Peter, because every bishop makes Peter’s confession (“You are the Christ, the Son of the living God,” Matt 16:16) and on that confession the Church is built. This is the Cyprianic background: for St. Cyprian of Carthage the cathedra Petri is the principle of the one episcopate held in solidum by all bishops, not the prerogative of a single see (Cyprian, De unitate ecclesiae 4–5; Ep. 33; see St. Cyprian of Carthage). Read against Cyprian, Leo’s “Peter speaks through his heir” is one local instance of what is true of the whole episcopate.

Second, the Orthodox tradition reads the primacy that does belong to Rome as a primacy of honour within a synodal Church — a first place in taxis among equal sees, exercised in council and answerable to the consensus of the Church, not a power above councils. The primacy is real but relational; it does not make its holder the source of the other bishops’ authority (Meyendorff, The Primacy of Peter: Essays in Ecclesiology and the Early Church, esp. the essays by Meyendorff and Afanasiev; Schmemann, in the same volume, “The Idea of Primacy in Orthodox Ecclesiology”).

Third, Orthodox writers distinguish Leo’s theology of Peter — much of which they can affirm — from the later juridical development read back into it. That the Roman see honours Peter, that Peter is the rock of confession, that the see of the martyr-apostles holds the first place — these are not the points at issue; the issue is whether Leo’s principalitas entails the universal, immediate jurisdiction of Vatican I, and the Orthodox answer is that it does not, and that to read it so is anachronism (Meyendorff, Imperial Unity and Christian Divisions, 148–152; Zizioulas, Eucharist, Bishop, Church; the continuity of this reading into the ninth century is treated in the St. Photius collection).

[Disputed: Roman position — Leo’s doctrine of the heres beati Petri and the principalitas witnesses to a primacy of universal jurisdiction by divine right, the patristic seed of the dogma defined at Vatican I (Pastor Aeternus, 1870; Ullmann, A Short History of the Papacy, 20–30; Wessel, Leo the Great, 285–321). Orthodox position — Leo witnesses to the honour of Rome and the Petrine confession shared by every bishop, but his primacy is a primacy of honour within a synodal Church, not a jurisdiction over it; the jurisdictional reading is a later development projected back upon him (Meyendorff, The Primacy of Peter; L’Huillier, The Church of the Ancient Councils, 267–296; Schmemann, The Historical Road of Eastern Orthodoxy, 119–125).]

Why the Two Readings Diverge

The divergence is not over the words of Leo, which both traditions can quote with respect, but over what theology of the Church those words presuppose. The Roman reading sets Leo’s Peter at the apex of a Church ordered from one centre; the Orthodox reading sets the same Peter within a Church ordered as a communion of sees, each itself Peter’s seat, gathered in council. Leo’s own practice — confirming the faith of Chalcedon while voiding its Canon 28 “by the authority of blessed Peter” — is read by Rome as the primacy operating and by the Orthodox as the early, visible parting of two ecclesiologies (treated in Leo and Canon 28).

Leo’s Petrine theology is genuinely his, genuinely the most developed of its age, and it has in fact been received in two ways; the choice between those receptions is not a choice about Leo’s sentences but about the shape of the Church itself. That choice the Orthodox Church has made: she venerates Leo as saint and Father, receives his witness to the honour of Peter’s see and confession, and does not receive the universal jurisdiction later read out of it — a judgment rendered not by this file but by the Church whose faith it documents.

References

Leo I, Sermones 2, 3, 4, 5 (in natali ipsius) and 82, 83 (in natali apostolorum Petri et Pauli) [PL 54; Sermon 4 at PL 54:149–151]; trans. Charles Lett Feltoe, Nicene and Post-Nicene Fathers, 2nd ser., vol. 12 (Buffalo, NY: Christian Literature, 1895).
Cyprian of Carthage, De catholicae ecclesiae unitate 4–5; Epistula 33; trans. ANF vol. 5.
Pastor Aeternus (First Vatican Council, 1870), Dogmatic Constitution on the Church of Christ.
Susan Wessel, Leo the Great and the Spiritual Rebuilding of a Universal Rome, Supplements to Vigiliae Christianae 93 (Leiden: Brill, 2008), 285–321.
Walter Ullmann, A Short History of the Papacy in the Middle Ages (London: Methuen, 1972), 5–30; and Gelasius I (492–496): das Papsttum an der Wende der Spätantike zum Mittelalter (Stuttgart: Hiersemann, 1981).
John Meyendorff et al., The Primacy of Peter: Essays in Ecclesiology and the Early Church, rev. ed. (Crestwood, NY: SVS Press, 1992).
John Meyendorff, Imperial Unity and Christian Divisions: The Church 450–680 A.D. (Crestwood, NY: SVS Press, 1989), 148–152.
Peter L’Huillier, The Church of the Ancient Councils (Crestwood, NY: SVS Press, 1996), 267–296.
Alexander Schmemann, The Historical Road of Eastern Orthodoxy, trans. Lydia Kesich (Crestwood, NY: SVS Press, 1977), 119–125.
John D. Zizioulas, Eucharist, Bishop, Church: The Unity of the Church in the Divine Eucharist and the Bishop During the First Three Centuries, trans. E. Theokritoff (Brookline, MA: Holy Cross Orthodox Press, 2001).
The Catholic Encyclopedia, s.v. “Pope St. Leo I” (New York: Robert Appleton, 1910).