DIADOCUS OF PHOTICEA, St. — The life of St. D., bishop of Photicea 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 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 its author; and finally, the prologue of the Historia persecutionis Africanae Provinciae written by Victor of Vita in 486, in which D. is praised for his defense of the Catholic faith.
This last text has recently led to the supposition that he may have been torn from his episcopal city by the Vandals (identified, on the basis of two inscriptions, with Limboni, to the northwest of Paranythia, today Adonat, in the region of Tesprotia) and taken to Carthage, where he may have died in Africa. In any case, his work reflects the life of the monasteries of the East; in the 5th century there were still cenobites, hermits, and solitaries in Greece, but above all in Egypt he could have become acquainted with monasticism: his teacher, Evagrius of Pontus, had lived in the desert of Scete.
Of D. the following works remain: Capita centum de perfectione spirituali or Capita gnosticum centum, a kind of spiritual guide, a path to perfection. Main themes: God and Grace; the discernment of spirits, spiritual life; Visio, a collection of aporias on a conversation with St. John the Baptist: praise of the desert, and discussion on the nature of divine apparitions; Sermo de ascensione D. N. Iesu Christi in which, at the end, he rejects Monophysitism.
The polemic, thus represented at the end of the Sermon, is even more evident in the Capitani centum, in which D. constantly attacks the messianism of the pseudo-Macarian homilies. This heresy, a crude materialism of historical origin, considered continuous prayer as the only way to exorcise the presence of Satan, who cohabits with Grace in the soul of the Christian. D. did not deny the efficacy of prayer; on the contrary, he recommends the repeated invocation of the name of Jesus (the monologist prayer); but he forbids the repeated administration of Baptism, which fills the soul with grace and drives out the demon. Such a polemic, however, does not by itself explain the success of the Capitani centum; the influence they exerted on the monasteries of Greece and the East derives from the balance of their spiritual doctrine; moreover, with the parts devoted to the discernment of spirits, they prepared the teaching of St. Ignatius of Loyola and St. Thérèse of the Child Jesus.