Byzantine humanist and theologian. b. Nicomedia, c. 1260; d. Constantinople, c. 1310. Born of a family that migrated from Nicomedia to Constantinople after 1261, Planudes attempted a civil career, but because of religiopolitical difficulties entered a monastery (1283) and changed his name from Manuel to Maximus. He was appointed hegumen, or director, of the monastery of the Five Saints on Mt. Auxentius in Bithynia by the metropolitan of Chalcedon, but soon returned to Constantinople. Despite the opposition of the Patriarch Athanasius I, he founded a monastery for laymen and opened a school close to the Emperor's palace with access to the imperial library. Grammar, mathematics, and science, as well as Latin, were the main subjects taught. The success of this novel enterprise in Constantinople was guaranteed when the children of the imperial family were sent there.
Possessing an excellent knowledge of Latin, Planudes had consistently favored a rapprochement with the Roman Church, and he strove to defend the orthodoxy of the Western theology under the Palaeologi Emperors michael viii and andronicus ii; under pressure the latter forced him to reconsider his opinions. Planudes was sent on diplomatic mission to Venice in 1295; but since it proved a failure, he refused a similar assignment to Cilicia somewhat later.
Among his numerous writings was a defense of the Western doctrine on the procession of the Holy Spirit that has not been preserved. Later he wrote, evidently under the pressure from Andronicus II, a De Spiritu Sancto adversus Latinos, published first by Arcudius (Rome 1630), which, in manuscript played an important part in the 15th-century polemics between bessarion, Gemistos plethon, and George metochites. Of his correspondence, some 121 letters have been preserved, and they have importance for the history of his epoch. He translated St. Augustine's De Trinitate into Greek, as well as works of Cicero, Ovid, Boethius, and Caesar. He also wrote hagiographical tracts, including an encomium of SS. Peter and Paul and another of St. Diomedes, discourses, and poetry. He was a figure of importance in the debates surrounding john xi beccus from 1282 to 1297.
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