DIADOCO of FOTICEA, saint. — The life of St. D., bishop of Foticca, in ancient Epirus, has come down to us only through three texts: a mention by Photius, who names D. among the opponents of the Monophysites at the Council of Chalcedon (451); the letter addressed to the emperor Leo I on the occasion of the death of Proterius of Alexandria (458), a letter of which D. is one of the signatories, perhaps even the author; finally, the prologue to the Historia persecutionis Africanae Provinciae written by Victor of Vita in 486, where D. is praised for his defense of Catholic doctrine.
The latter text has recently led to the supposition that he was torn from his episcopal city by the Vandals (identified, on the basis of two inscriptions, with Limboni, northwest of Paranythia, today Adonat, in Thesprotia) and taken to Carthage; did he die in Africa? In any case, his work reflects the life of the monasteries of the East; in the fifth century there were still cenobites, hermits, and solitaries in Greece; but it was above all in Egypt that he was able to encounter monasticism: his teacher, Evagrius Ponticus, had lived in the desert of Scetis.
The following works of D. survive: Capita centum de perfectione spirituali or Capita gnostica centum, a kind of spiritual guide, a path to perfection. Principal themes: God and Grace; the discernment of spirits, the spiritual life; Visio, a collection of aporiae concerning a conversation of St. John the Baptist: praise of the desert, and discussion of the nature of divine apparitions; Sermo de ascensione D. N. Iesu Christi, in which he ultimately rejects Monophysitism.
The polemic, thus represented at the end of the Sermon, is even more evident in the Capita centum, in which D. constantly attacks the Messalianism of the Pseudo-Macarian homilies. This heresy, a crude materialism of historical origin, regarded continual prayer as the only means of exorcising the presence of Satan, cohabiting with Grace in the Christian’s soul. D. does not deny the efficacy of prayer; on the contrary, he recommends the repeated invocation of the name of Jesus (monologist prayer); but he prohibits the repetition of Baptism, which fills the soul with grace and drives out its demon. Such a polemic, however, did not by itself explain the success of the Capita centum; the influence they exerted upon the monasteries of Greece and the East derives from the balance of their spiritual doctrine; moreover, with the sections devoted to the discernment of spirits, they prepared the teaching of St. Ignatius of Loyola and St. Thérèse of the Child Jesus.