BONOSUS, bishop of Nais(s)us. — He is more commonly known as bishop of Sardica, but this is a mistake by Marius Mercator. It is not certain when he was elected to the episcopal see; he was certainly bishop in 391, since the synod held that year at Capua dealt with his two doctrines.
A letter from Pope Siricius shows that B., like Helvidius and Jovinian, denied the perpetual virginity of Mary, affirming that she had other children by St Joseph; Gennadius then attests that B. also followed the error of Photinus, denying the divinity of Jesus Christ. The Synod of Capua did not pass judgment on B.’s doctrines, but decreed that an inquiry be made by the bishops of Illyricum under the presidency of Anysius (Anysius) of Thessalonica. The inquiry must have gone against B., since he was forbidden to exercise his episcopal functions. Instead of submitting, B.—even after appealing to St Ambrose, who advised him to obey—continued to exercise his office, even ordaining clerics. When B. died, probably before 414, a controversy arose over the validity of those irregularly performed ordinations. The bishops of Illyricum recognized them, and even Innocent I, while approving the decisions of the synod presided over by Anysius, ordered Marcian, B.’s successor, to admit two clerics ordained by him to communion. Later, however, on receiving further evidence, Innocent distinguished between ordinations performed before or after B.’s condemnation, forbidding admission to the latter.
B. later had followers, especially on the Christological doctrine, more or less openly tending to adoptionism; but they were always few and confined to the Danubian provinces, where they lingered on until the 6th century.