BARLAAM of SEMINARA. — Theologian and scientist of the 14th century, born around 1290 at Seminara (Calabria) and died in 1350 as bishop of Gerace. Contrary to common opinion down to our own day, B. was not born into the Catholic Church, but within the schism (cf. his testimony in one of his pamphlets against the dogma of the procession of the Holy Spirit *ab utroque*, the 7th in the series, in the codex Parisinus graecus 1218, fol. 506 of the 15th century).
As a young man he received a thorough education in one of the Calabrian monasteries nominally dependent on some Catholic bishop of the Byzantine rite, but in fact loyal to the dissident patriarchate of Byzantium. Moving to Constantinople in 1326–27 as a teacher of sciences in the monastery of St. Saviour, he soon became its abbot. He was also appointed professor of theology and patristic exegesis at the Imperial University, thereby arousing the jealousy of Nicephorus Gregoras, who challenged him to a public scientific debate. Gregoras himself reports this, having published his *Florentios* to demonstrate that he had defeated the Calabrian. After a sojourn in Thessalonica, B. was recalled to Constantinople to discuss union with the legates of Pope John XXII.
It was then that he composed his 21 pamphlets against the Latins (PG 151, 1249–53: the titles and incipits of the treatises).
Some of these pamphlets were criticized by Gregory Palamas. Perhaps for this reason B., shortly afterwards, wrote against the method of prayer of the Hesychasts (v.) of Mount Athos, which was tainted with illuminism, and against the new theology of Palamism. Thereupon (1341) the dissident Byzantine patriarch intervened, and B., having confessed, was forced to recant. Humiliated, B. returned to the West, where in 1339 he had been summoned to the papal court at Avignon as legate of Andronicus III, who demanded from the Pope a crusade against the Turk. Nothing was achieved because the Pope made preliminary union with the Roman See a condition. B.’s ideas on this question are known to us from two discourses composed at that time and recently published (C. Giannelli, in *Miscellanea Giovanni Mercati*, III [Studi e Testi, 123], p. 52, under the title: *Un progetto di B. Calabro per l'unione delle Chiese*), not to be confused with the minutes of the session held at Avignon of which Allatius gives extracts (PG 151, 1331–43).
At Avignon B. formed a friendship with Petrarch, who received from him lessons in Platonic philosophy. These contacts and his studies on the dogmatic discrepancies between East and West induced B. to become a Catholic. It was Petrarch who urged him to take this step in 1342, still at Avignon, where B. had returned once more. Thanks to his influential friend, B. obtained from the papal court a pension and somewhat later the Byzantine-rite bishopric of Gerace near his native Seminara. Consecrated at Avignon by Cardinal Bertrand du Pouget, he was again summoned to the court in 1346 for a mission to the Byzantine empress Anna of Savoy, then regent. It was doubtless a matter of religious union, but the triumph of John Cantacuzenus in 1347 brought everything to naught. B. returned to Gerace, where he died.
Numerous works of his survive, many still unpublished, and almost always brief though of dense content. Among the lost books should be mentioned his *Against the Messalians*, i.e. against the Palamites. Having become a Catholic, B. refuted his own earlier views on the primacy of the Pope and the procession of the Holy Spirit. Three of his pamphlets (PG 151, 1255 sqq.) are a notable defence of Catholicism. Among the published works we may also note: 1) *Two books on ethics according to the Stoics*, in Latin (PG 151, 1341–64); 2) *Αὐγύστικη*, i.e. reasoned arithmetic in 6 books (Strasbourg 1572); 3) *Commentarius arithmeticus secundi libri Euclidis* (published among the *Opera omnia* of Euclid in the *Bibliotheca classica graecorum et latinorum* Teubneriana, of Leipzig); 4) *Seven letters on the beginnings of the Hesychast controversy* (ed. G. Schirò in *Archivio storico per la Calabria*, 1–8 [1931–38]; the edition is unfortunately defective).