Book V. Hilary now points out (§ 1) the controversial strength of the Arian position. If he is silent in face of their assertion, they will claim that he agrees with them that the Son is God only in some inferior sense. On the other hand, if he opposes them, he will seem to be contradicting the Mosaic revelation of the Divine unity. In § 2 he recapitulates the argument of Book IV., that the witness of Scripture proves that God is not a solitary Person; that, as he says, there is God and God. But the Arians had a further loophole; their creed asserted (§ 3) one true God. They might argue that Christ is indeed God, but of a nature different from that of the Father. In refutation of this Hilary goes once more through the history of creation (§§ 4–10), proving that the narrative reveals not only the Son’s share in that work, but also His equality and oneness of nature with the Father; in other words, that He is not only God but true God. The same truth is demonstrated from the life of Abraham (§§ 11–16). Moreover, these self-revelations of the Son (as the Angel, on various occasions) are anticipations of the Incarnation. He was first seen in flesh, afterwards born in flesh. The Arians concentrate their attention on the humble conditions of Christ’s human life, and so, from want of a comprehensive view, fail to discern His true Godhead. But Hilary will not anticipate the evidence of the Gospels (§§ 17, 18). He returns to the Old Testament, and proves his point from Jacob’s visions (§§ 19, 20), and by the revelations made to Moses (§§ 21–23). After a summary and an enforcement of the preceding arguments (§§ 24, 25), he proceeds to prove from certain passages of Isaiah that the Prophet recognised the Son as true God (§§ 26–31), and that St. Paul understood him in that sense (§§ 32, 33). Then, in §§ 34, 35, the result which has been attained is dwelt upon. Hilary shews that it is the Arians who fail to recognise the one true God; for Christ is true God, yet not a second God. Finally, in §§ 36–39, Moses, Isaiah, and Jeremiah are adduced as testifying that Christ is God from God, and God in God.