This was the deliberate purpose of Hilary, and he had certainly counted its cost in immediate popularity and success. For though, as we have seen, the work did produce, as it deserved, a considerable effect at the time of its publication, it has remained ever since, in spite of all its merits, in a certain obscurity. There can be no doubt that this is largely due to the Mezentian union with such a document as Arius’ Epistle to Alexander of the decisively important section of the De Trinitate. The books in which that Epistle is controverted were those of vital interest for the age; and the method which Hilary’s plan constrained him to adopt was such as to invite younger theologians to compete with him. Future generations could not be satisfied with his presentation of the case. And again, his plan of refuting the Arian document point by point v. 6., contrasting as it does with the free course of his thought in the earlier and later books, tends to repel the reader. The fourth book proves from certain texts that the Son is God; the fifth from the same texts that He is true God. Hence this part of the treatise is pervaded by a certain monotony; a cumulative impression is produced by our being led forward again and again along successive lines of argument to the same point, beyond which we make no progress till the last proof is stated. The work is admirably and convincingly done, but we are glad to hear the last of the Epistle of Arius to Alexander, and accompany Hilary in a less embarrassed enquiry.