The Tome of Leo

On 13 June 449 Pope St. Leo the Great sent to Flavian of Constantinople the dogmatic letter (Ep. 28) that the Church calls the Tome: a lucid confession of two complete and undiminished natures united in the one Person of the Word, each retaining its properties and its proper activity. Suppressed at Ephesus II, it was read and scrutinized at Chalcedon against Cyril’s letters, acclaimed, and received into the Definition. It is a document of the Fourth Ecumenical Council and therefore of the Church’s faith — and it is also the single text that gave the rejecters of Chalcedon their sharpest grievance.

Tradition: Pan-Orthodox

Occasion

The Tome was occasioned, not theorized. Eutyches, deposed by Flavian’s Home Synod in November 448, appealed to Rome; Flavian sent Leo a full record of the proceedings. By spring 449 the bishop of Rome had before him both the appellant’s complaint and the patriarch’s account, and the dispute that had begun in a monastery of the capital had become a matter on which Rome was asked to pronounce (Leo, Epp. 20–21, 22, 23; trans. Hunt, FOTC 34). Leo answered on 13 June 449 with the letter addressed Dilectissimo fratri Flaviano Leo episcopus (Leo, Ep. 28; PL 54:755–782; trans. Feltoe, NPNF, Second Series, vol. 12). He intended it to be read into the record of the general council Theodosius II had summoned to Ephesus. It was not.

The letter is short, lucid, and pastoral, organized less as a syllogism than as a rule of faith expounded against a specific error. Leo first rebukes Eutyches for “unskilfulness” — for not knowing the very Creed he claimed to defend — and then walks through the Christology of the baptismal creed phrase by phrase, showing that the catholic confession already contains everything Eutyches had abandoned (Leo, Ep. 28.1–2; trans. Feltoe, NPNF, Second Series, vol. 12).

The Two Natures in One Person

The doctrinal core is a confession of two complete natures in the one Person of the Word. Against Eutyches’ single nature, Leo insists that the Son of God, remaining in the form of God and equal to the Father, “took the form of a slave without stain of sin, increasing the human and not diminishing the divine” (Ep. 28.3; trans. Feltoe). The Incarnation is addition, not subtraction or fusion: the Godhead lost nothing, the manhood was real and entire. The two natures are not two persons but one and the same Son, in whom each nature is preserved whole — “complete in what was His own, complete in what was ours” (Ep. 28.3–4; trans. Feltoe).

Leo’s grammar is precise and deliberately Latin. The single subject is the one persona of the Word; the naturae are what is doubled. Because there is one persona, the properties of both natures may be predicated of the one Christ — the communicatio idiomatum, by which it is true to say that the Son of God was crucified and that the Son of Man came down from heaven, the title given according to one nature while the act belongs to the other (Ep. 28.5; trans. Feltoe; Grillmeier, Christ in Christian Tradition, vol. 1, 2nd ed., London: Mowbray, 1975, 534–539). This is the same conviction the Greek tradition guarded with the Theotokos.

The Hinge Sentence

The single sentence over which Chalcedon, and the schism that followed it, would turn comes in the third section. In the Latin: “Agit enim utraque forma cum alterius communione quod proprium est: Verbo scilicet operante quod Verbi est, et carne exsequente quod carnis est” (Ep. 28.4; PL 54:767). In the NPNF rendering: “For each form does what is proper to it with the co-operation of the other; that is the Word performing what appertains to the Word, and the flesh carrying out what appertains to the flesh” (trans. Feltoe, NPNF, Second Series, vol. 12).

The sentence does two things at once, and both must be held together to read it rightly.

First, it affirms the distinct proper operation of each nature: the Word works what is the Word’s — the miracles, the divine majesty — and the flesh undergoes what is the flesh’s — hunger, weariness, suffering, death. The integrity of the humanity, which Eutyches denied, is thereby guarded at the level of activity: a nature that does nothing of its own is no real nature at all. This is precisely the insight that St. Maximus the Confessor would develop two centuries later into the doctrine of the two natural energies and the two natural wills (see Sophronius and Maximus).

Second, and decisively, the phrase cum alterius communione — “in communion with the other” — binds the two operations into a single concrete agency. The two forms never act in isolation, as though two subjects took turns; each acts always in communion with the other, because there is only one persona who acts in and through both. Leo immediately illustrates: one of these “shines out in miracles,” the other “succumbs to injuries” — yet it is the same Christ who raises the dead and weeps at the tomb (Ep. 28.4; trans. Feltoe). The clause that guarantees the two is held in the same breath as the clause that guarantees the one.

The Western Sources

The Tome is not an ad hoc composition but the deposit of a long Latin tradition, and its idiom — natura, forma, persona, substantia — is the inheritance of the Western Fathers rather than of the Alexandrian school. Behind Leo’s two-natures language and his communicatio idiomatum stands Tertullian, who first fixed for the Latin Church the formula of one person in two substances (Adversus Praxean 27; Grillmeier, vol. 1, 528–529; Wessel, Leo the Great and the Spiritual Rebuilding of a Universal Rome, Leiden: Brill, 2008, 220–238); behind it stand Hilary of Poitiers, Ambrose, and above all Augustine, whose teaching on the one Person and the integrity of the assumed humanity supplies the letter’s deep structure (Augustine, Enchiridion 35–40; Wessel, 222–230). Leo signals this rootedness by appealing not to a theologian’s argument but to the regula fidei confessed in baptism: the Tome presents itself as the catholic tradition speaking (Leo, Ep. 28.1, 5; trans. Feltoe).

Convergence and Difference with Cyril

Here lies the fact that governs the Tome’s whole reception. In substance Leo and Cyril confess one Christ: a single subject, true God and true man, the Virgin truly Theotokos, the humanity real and entire; both reject Nestorius’ two sons and both reject the absorption of the manhood. But in vocabulary the two differ sharply. Cyril’s governing formula was mia physis tou Theou Logou sesarkōmenē, using physis and hypostasis nearly as synonyms for the one concrete subject; Leo’s is two natures in one person, natura naming exactly what is doubled and persona what is single (Meyendorff, Christ in Eastern Christian Thought, Crestwood, NY: SVS Press, 1975, 23–46; Grillmeier, vol. 1, 543–550). The Tome makes no use of Cyril’s mia physis and does not move within his terminology at all; it reaches its dyophysite confession by the independent road of the Latin tradition.

This is why some Eastern bishops at Chalcedon — from Palestine and Illyricum — hesitated when the Tome was read, and why the council appointed a committee to test it against the standard of Cyril’s letters before ratifying it (ACO II.1.2; Price and Gaddis, The Acts of the Council of Chalcedon, Liverpool: Liverpool University Press, 2005, vol. 2, 9–25). That the council examined the Tome and did not simply impose it is itself dogmatically significant: Chalcedon received a Roman document because it was shown to agree with the Alexandrian Father whom the whole East revered. When the scrutiny was satisfied the acclamation was unreserved: “Peter has spoken through Leo; this is the faith of the Fathers; Leo and Cyril teach alike” (ACO II.1.2; Price and Gaddis, vol. 2, 24–25).

Why the Tome Gave Special Offense

The Tome is, for the Orthodox Church, a document received by an Ecumenical Council as a standard of the faith. It is also the text that drew the sharpest animus from those who rejected the council, and the reason is precise and should be stated without caricature.

To a strict Cyrilline reader, “each form does what is proper to it” distributed the acts of Christ between two operating subjects — the Word doing the miracles, the flesh doing the suffering — and so reintroduced, under cover of orthodoxy, the two acting agents of Nestorius that the whole Alexandrian tradition had fought to exclude. Severus of Antioch made this the center of his case, insisting against Leo on the one composite activity of the one incarnate Word, whose every act is the act of the single subject who is God made flesh (see Severus, Jacob Baradaeus, and the Parallel Hierarchies; Lebon, Le monophysisme sévérien, Louvain, 1909; Allen and Hayward, Severus of Antioch, London: Routledge, 2004; Meyendorff, Christ in Eastern Christian Thought, 1975, 32–46).

The objection is intelligible, and it is not an objection to the humanity of Christ. It rests, however, on a misreading that the Tome’s own text refutes: Leo wrote cum alterius communione, and a reading which drops that clause is not reading Leo. What the council saw, and what the Church has confessed since, is that the two proper operations are the two operations of one who acts, and that a Christ whose humanity performs nothing human is not a Christ with a human nature at all. The Sixth Ecumenical Council would make this explicit, defining two natural energies and two natural wills “which undergo no division, no change, no partition, no confusion” (Constantinople III, Exposition of Faith, 681; trans. Tanner, Decrees of the Ecumenical Councils) — a definition that is the Tome’s hinge sentence raised to dogma.

References

Leo the Great. Epistle 28 (the Tome to Flavian), 13 June 449; PL 54:755–782. Trans. Charles Lett Feltoe, NPNF, Second Series, vol. 12; also Edmund Hunt, FOTC 34.
Leo the Great. Epistles 20–23. Trans. Hunt, FOTC 34.
Council of Chalcedon (451). Acts, sessions 2 and 4 (the reading and scrutiny of the Tome), in Acta Conciliorum Oecumenicorum II.1.2, ed. Eduard Schwartz; trans. in Price and Gaddis (below), vol. 2, 9–25.
Council of Constantinople III (680–681). Exposition of Faith. In Tanner, ed., Decrees of the Ecumenical Councils, and Percival, ed., NPNF, Second Series, vol. 14.
Tertullian. Adversus Praxean 27. Augustine. Enchiridion 35–40.
Price, Richard, and Michael Gaddis. The Acts of the Council of Chalcedon. 3 vols. Liverpool: Liverpool University Press, 2005.
Grillmeier, Aloys. Christ in Christian Tradition. Vol. 1, 2nd ed. Trans. John Bowden. London: Mowbray, 1975.
Wessel, Susan. Leo the Great and the Spiritual Rebuilding of a Universal Rome. Leiden: Brill, 2008.
Meyendorff, John. Christ in Eastern Christian Thought. Crestwood, NY: St. Vladimir’s Seminary Press, 1975.
Lebon, Joseph. Le monophysisme sévérien. Louvain: Van Linthout, 1909.
Allen, Pauline, and C. T. R. Hayward. Severus of Antioch. London: Routledge, 2004.
Tanner, Norman P., ed. Decrees of the Ecumenical Councils. 2 vols. Washington, DC: Georgetown University Press, 1990.