MESARITES, GIOVANNI and NICOLAO. — These two brothers distinguished themselves in the religious controversies during the time of the Latin Empire of Constantinople. Giovanni (d. 1207) embraced the monastic state and was appointed by Alessio III professor of exegesis at the Constantinopolitan school. His brother Nicolao (d. ca. 1216–22), initially a deacon of S. Sofia, became in 1208 referendary of the patriarch of Nicaea and was called in 1212 to occupy the metropolitan see of Ephesus.
G. is the author of a commentary on the Psalms, now lost. To N. belong several synodal letters and other writings published by A. Heisenberg, concerning the disputes of December 1204 between the papal legate Pietro di Capua and G. M.; that of August 1206 between the Latin patriarch of Constantinople, Toma Morosini, and N. M.; and finally the controversy of December 1212 between the representative of Cardinal Pelagius—probably Ponzio d’Ilerda—and N. himself. These disputes concerned the Roman primacy, against which the M. adopted a position of complete intransigence, even denying the primacy of the apostle s. Pietro, and the procession of the Holy Spirit from the Son. On this subject the M. adhere to the doctrine of Fazio, to his explanations of Holy Scripture, and repeat the well-known dialectical argument against the Filioque.