In the language of that time, the "Three Chapters" were called:

1. All the works of Theodore of Mopsuestia;

2. Works of Blazh. Theodoret of Cyrus, in which he attacks the anathematisms of St. Cyril of Alexandria and the Council of Ephesus (431) and rejects any form of theopaschism;

3. The letter of Iva to Marius Perse, in which the reconciliation of 433 between St. Cyril and the Easterners is explained; Iva presented this reconciliation as the capitulation of the Bishop of Alexandria.

In 544, Justinian issued an edict pronouncing the anathema of each of these chapters (kejalaia). Bl. Theodoret and Iva were not personally condemned, since they were rehabilitated in Chalcedon, where they unequivocally anathematized Nestorius. It was believed that by doing so they renounced all the Nestorian views that had taken place in their previous works. Justinian's decree contributed to the development of political processes and the dogmatic movement, and led to the Council of 553.

The Confession of Faith (omologia pistews) compiled by Justinian in 551 and addressed to the fullness of the Catholic Church contains the draft and the main motives for the decisions of 553.40 The emperor stubbornly defended the orthodoxy of the theopaschist formulas, which became for him the criterion of Orthodoxy. But he does not do this to the detriment of the Chalcedonian creed; resolutely rejecting the idea of the union (sugcusis) of the Godhead and humanity in Christ, Justinian firmly insists on the need to recognize the two natures, condemning the reluctance of the Monophysites to "count the number (ariqmos) of natures." The unity of Christ is expressed by the concept of hypostasis, not nature; thus, Justinian (following Leontius of Jerusalem) is fully aware of the difference between nature and hypostasis, remaining a convinced adherent of Chalcedon. Not fully accepting the terminology of Leontius, Justinian assimilated its main idea: nature can exist only in hypostasis; otherwise it remains only an indefinite abstraction (aoriston). Thanks to the Hypostasis of the Logos, the humanity of Christ receives in the womb of Mary the fullness of its being. Thus it is possible for the hypostasis to become complex (upostasis sunqetos) because, as the source of existence, the hypostasis cannot lose its self-identity (to idion), while the components of a complex nature (jusis sunqetos) are deprived of their independent existence. If Christ had a complex nature, as Severus asserted, He would not have been God or man, but a new nature; whereas in reality He is both God and man in His complex Hypostasis. In trying to define this unity, Leontius of Byzantium used the image of a human individual consisting of soul and body, two different natures united in one hypostasis. Justinian understood the inadequacy of this image, which the Monophysites, who did not share the Origenist views of Leontius, immediately interpreted in their favor, since the body and the soul constitute one human nature. The emperor argued that this image could only be used to describe the hypostatic unity of Christ itself, but not its complex character, since the two natures in Christ were neither complementary, like soul and body, nor simultaneously created, since the uncreated Godhead existed before the Incarnation.

Justinian openly opposed Monophysitism, defending a single understanding of hypostasis and waging a polemical battle with Severus on the question of the "number" of natures. Nevertheless, he made a number of significant terminological concessions to Severus. In particular, Justinian believed that the two natures in Christ could be distinguished only "verbally or contemplatively, and not as two different things" (logw monw kai qewria, ou mhn autwn twn pragmatwn ecei thn diaresin). It was in this sense that Severus understood the two natures (duo juseis en qewria). In addition, the imperial confession of faith proclaimed the true Orthodox formula of St. Cyril (mia jusis tou Qeou Logou sesarkwmenh). After a brief exposition of the Diphysite Christology, the Emperor continues: "In professing this teaching, we at the same time accept the expression of St. Cyril, who taught only about the incarnate nature of God the Word..., since whenever the Holy Father said mia jusis tou Qeou Logou sesarkwmenh), he used the word "nature" in the sense of "hypostasis."

Justinian further cites excerpts from the "Epistle to Suxens" of St. Cyril, trying to prove that only the terminology of St. Cyril is colored by Monophysitism, while the essence of his teaching agrees with the definition of the Council of Chalcedon.

Justinian met the Monophysites halfway as far as his loyalty to Chalcedon allowed. Many Orthodox, such as Hypatius of Ephesus at the conference of 532, unconditionally accepted only those works of St. Cyril that had been officially approved in Ephesus and Chalcedon. Justinian's religious policy, on the contrary, was to fully restore the authority of St. Cyril among the Orthodox, and to lead the Monophysites to accept the Council of Chalcedon. There was only one way to achieve unity of faith: it was necessary to show both sides that the contradictions between St. Cyril and Chalcedon were no more than terminological in nature. In 553, this policy was officially adopted as a result of the posthumous condemnation of those who, of course, could no longer defend themselves, but whose writings represented a serious obstacle to the final triumph of Alexandrian theology.

Justinian's "Confession of Faith" contained 14 anathemas, which the Council of 553 simply reworked without changing the content. The significance of the anathemas is clear: by submitting them for the approval of the Council, Justinian sought to remove from Chalcedon the accusations of Nestorianism (see especially anathemas 5, 6 and 14). The repeated condemnation of the Nestorianism of the Three Chapters, as it is contained therein, is expressed in the repeated affirmation of the unity of the subject of the incarnate Word (anathemas 2, 3, 4 and 5), in addition, in the solemn proclamation of theopaschism (anathema 10) and, in addition, in the prohibition (anathema 13 concerning the works of Theodoret) to express any disagreement with the works of St. Cyril, in particular with the "Twelve Chapters" against Nestorius, which were not officially accepted at the Councils of Ephesus and Chalcedon. There remained only one obstacle to the triumph of Cyril's theology. The Council declared that the expression mia jusis ("one nature") could and should, under the threat of anathema, be understood only in the meaning of mia upostasis (anathema 8). Thus, St. Cyril is recognized as Orthodox, but his Orthodoxy should be understood in the light of the Chalcedonian definition of faith, and, conversely, Chalcedon should not be considered as a renunciation of St. Cyril. Of course, for the Monophysites this was a stumbling block, although the Council met them halfway, accepting the expression of Justinian, according to which the difference between the natures in Christ is only contemplative (en qewria, anathema 7). And indeed, did not Severus of Antioch say the same thing?

A direct condemnation of the "Three Chapters" was included in the last three anathemas. Only Theodore of Mopsuestia was personally condemned. The names of Iva and Theodoret were formally protected by the authority of the Fourth Ecumenical Council. The latter continued to be read and quoted along with the other great teachers of the Greek Church; as for Iva, the text in which he is mentioned cast doubt on the authenticity of his letter to Marius, and thus his personal authority was not affected.

Nevertheless, it is clear that the significance of the theological decisions of 553 is broader than the problems associated with individuals. Even if Theodore's theology could indeed be interpreted in the Orthodox sense (which, however, is doubtful), the proclamation of St. Cyril of Alexandria as an absolute regula fidei in Christological matters, undertaken by Justinian and his Council, was an extremely important event both for the East, where it determined the further development of theology, and for the West, where it was accepted only after long hesitation.

The Fifth Ecumenical Council did not resolve all the problems connected with the mystery of the Incarnation, but by rehabilitating Cyril's teaching on the unity of the subject in Christ, it actualized the enormous significance of the concept of the hypostatic unity of the incarnate Word. Against Apollinarius, the Council affirmed that human nature, hypostasized by the Word, was flesh animated by the rational soul (sarka emyucwmen yuch logikh kai noera, anathema 4), and consequently the humanity of Christ was true humanity, and Christ, as affirmed at Chalcedon, was completely consubstantial with us in His humanity, but the hypostasis of His humanity was the Hypostasis of the Eternal Word. This decision of the Council, which was an expression of New Alexandrian theology, made it impossible to identify hypostasis with the concept of self-consciousness or mind. As a man, Christ possessed everything that is inherent in man, but He was not a human person. Birth, temptations, suffering, and death were all truly human in Him. But His Self, the source and subject (agent) of all these necessary states of freely perceived human nature, was the Word, which is also the basis both for the communicatio idiomatum and for the final deification of human nature. All this is possible only if the hypostasis retains its "open character," i.e., it is thought of as the source and foundation, and not as the content of a concrete being, or as one of the aspects of natural, divine, or human existence. The energies and actions of human nature have not ceased to be truly human because it has been "hypostasized in the Word."

It was the concept of hypostasis that allowed Byzantine theology to preserve in its understanding of the Incarnation the positive content of Antiochian thought and the fundamental meaning of the Tomos of Pope Leo, according to which each nature "acts as it is peculiar to it."