Introduction
Hilary had taken no part in the Synod held at Ancyra in the spring of a.d. 358, but he had been made acquainted with its decisions and even with the anathemas which the legates of that Synod concealed at Sirmium. He saw that these decisions marked an approach. The horror which was felt at the Sirmian Blasphemia by those Eusebians whose only objection to the Nicene faith was that they did not understand it, augured well for the future. At the same time the majority of the Eastern bishops were deliberately heretical. It was natural that Hilary should be anxious about the episcopate of the West.
He had been in exile about three years and had corresponded with the Western bishops. From several quarters letters had now ceased to arrive, and the fear came that the bishops did not care to write to one whose convictions were different to their own. Great was his joy when, at the end of the year 358, he received a letter which not only explained that the innocent cause of their silence was ignorance of his address, but also that they had persistently refused communion with Saturninus and condemned the Blasphemia.
Early in 359 he dispatched to them the Liber de Synodis. It is a double letter, addressed to Western bishops, but containing passages intended for Orientals, into whose hands the letter would doubtless come in time. Hilary had recognized that the orthodox of the West had kept aloof from the orthodox of the East, firstly from ignorance of events, secondly from misunderstanding of the word ὁμοούσιος, and thirdly from the feelings of distrust then prevalent. These facts determined the contents of his letter.
He begins with an expression of the delight he experienced on receiving the news that the Gallican bishops had condemned the notorious Sirmian formula. He praises the constancy of their faith.
He then mentions that he has received from certain of their number a request that he would furnish them with an account of the creeds which had been composed in the East. He modestly accedes to this request beseeching his readers not to criticise his letter until they have read the whole letter and mastered the complete argument. His aim throughout is to frustrate the heretic and assist the Catholic.
In the first or historical division of the letter he promises a transcription, with explanations, of all the creeds drawn up since the Council of Νιχiα. He protests that he is not responsible for any statement contained in these creeds, and leaves his readers to judge of their orthodoxy.
The Greek confessions had already been translated into Latin, but Hilary considered it necessary to give his own independent translations, the previous versions having been half-unintelligible on account of their slavish adherence to the original.
The historical part of the book consists of fifty-four chapters (c. 10-63). It begins with the second Sirmian formula, and the opposing formula promulgated at Ancyra in a.d. 358. The Sirmian creed being given in c. 10, Hilary, before proceeding to give the twelve anathemas directed against its teaching by the bishops who assembled at Ancyra, explains the meaning of essentia and substantia. Concerning the former he says, Essentia est res quæ est, vel ex quibus est, et quæ in eo quod maneat subsistit. This essentia is therefore identical with substantia, quia res quæ est necesse est subsistat in sese. The Ancyran anathemas are then appended, with notes and a summary.
In the second division (c. 29-33) of the historical part, Hilary considers the Dedication creed drawn up at Antioch in a.d. 341. He interprets it somewhat favourably. After stating that the creed is perhaps not sufficiently explicit in declaring the exact likeness of the Father and the Son, he excuses this inadequacy by pointing out that the Synod was not held to contradict Anomœan teaching, but teaching of a Sabellian tendency. The complete similarity of the Son’s essence to that of the Father appears to him to be guarded by the phrase Deum de Deo, totum ex toto.
The third division (c. 34-37) contains the creed drawn up by the Synod, or Cabal Synod, which met at Philippopolis in a.d. 343. Hilary does not discuss the authority of the Synod; it was enough for his purpose that it was composed of Orientals, and that its language emphatically condemns genuine Arianism and asserts the Son is God of God. The anathema which the creed pronounces on those who declare the Son to have been begotten without the Father’s will, is interpreted by Hilary as an assertion that the eternal Birth was not conditioned by those passions which affect human generation.
The fourth division (c. 38-61) contains the long formula drawn up at Sirmium in a.d. 351 against Photinus. The twenty-seven anathemas are then separately considered and commended. The two remaining chapters of the historical part of the work include a reflection on the many-sided character of these creeds both in their positive and negative aspects. God is infinitus et immensus, and therefore short statements concerning His nature may often prove misleading. The bishops have used many definitions and phrases because clearness will remove a danger. These frequent definitions would have been quite unnecessary if it had not been for the prevalence of heresy. Asia as a whole is ignorant of God, presenting a piteous contrast to the fidelity of the Western bishops.