HILA'RIUS, SAINT, was born at Poitiers, of which place he was afterwards made bishop about 350. He is distinguished in occlesiais tied history by the active part which ho took against the Arians during the reign of Constantims. Ile was banished by this emperor to Phrygia, shortly after he had been elected Bishop of Poitiers, on accouut of his defence of Athanasius, in the council of 136ziers, against Saturninus, bishop of Aries. In the East he continued hie exertions in favour of the Catholic faith. In 359 be attended the council of Seleucia iu Isanria, which had been summoned by order of Constantine, and boldly defended the doctrine of the Trinity against the Arian bishops, who formed the majority of the council. He afterwards followed the deputies of the council to the emperoie court, and presented a petition to Constantine, in which he desired permission to dispute publicly with the Arians in the emperor. presence. In order to get rid of so formidable an opponent, the Arians, it is said, induced the emperor to °end him away from the court; but previous to his departure, llilarius wrote an invective against Constantius, in which he denounced him as Anti-Christ, and described him as a person who had only professed Christianity in order that he might deny Christ. After the Catholic bishops had recovered their liberty under Julian, Hilarius assembled several councils in Gaul for the re-establishment of the Catholic faith and the condemnation of Arian bishops. He also travelled in Italy for the same purpose, and used every exertion to purify the churches of that country from all Arian heresies. When Auxentius was appointed Bishop of Milan by the Emperor Valentinian in 364, Hilarius presented a petition to the emperor, in which he denounced Auxentius as a heretic. Though this charge was denied by Auxentius,
Hilarius still continued his attacks upon his orthodoxy, and created so much confusion in the city that he was at length ordered to retire to his own diocese, where he died shortly afterwards, in the year 367.
The most important of Hilarius's works are :-1, ' Twelve Books concerning the Trinity ;' 2, A Treatise on Synods,' addressed to the bishops of France and Britain, in which he gives an accouut of the creeds which had been adopted by the Eastern churches since the Council of Nice ; 3, ' Three Discourses addressed to Constantius; on the Arian controversy ; 4, 'A Commentary on St. Matthew ; 5, 'A Commentary on the Psalms' (these commentaries are entirely takeu from the commentaries of St,. Augustine); 6, ' A Book of Fragments,' which contains extracts from several of the last works of The writings of Hilarius are very obscure, and ofteu unintelligible, I which ie owing owin to his fondness for antithesis and metaphorical expressions, and to the length and intricacy of his periods. Though he was very severe in condemning the erroneous opinions of others, he differed in many particulars from the doctrines of the Catholic Church, especially in respect to the person of Christ ; he held also that the souls of men are material.
The works) of Hilarius have been published by 31irmue, Paris, 1544; Erasmus, Basel, 1523, reprinted 1526, 1535, 1550, 1570; Gillet, Paris, 1572, reprinted with several improvements 1605, 1631, 1652; by the Benedictinea, Paris, 1693; the Marquis de Maffei, Verona, 1730; and Oberthiir, 4 vols. 8vo, 1781-33.
(Du Piu, Ecclesiastical fliatory, vol. ii., pp. 64-79, English translation; Lardoer, Credibility, Works, vol. iv., pp. 178, 179.)