Book IX. After a summary (§ 1) of the results already obtained, Hilary returns, in § 2, to certain of the Arian proof-texts, and warns his readers that their life depends on the recognition in Christ of true God and true man, for it is this twofold nature which makes Him the Mediator (§ 3). Universal analogy and our consciousness of the capacity to rise to the life in God convince us of these two natures in Him, Who makes this rise possible (§ 4). But heresy lays hold of words spoken by Christ Incarnate, appropriate to His humility as Man, and assigns them to Him in His previous state; thus they make Him deny His true Godhead. But His utterances before the Incarnation, during His life on earth, and after His return to glory, must be carefully distinguished (§§ 5, 6). Hilary now examines the aims and achievements of Christ Incarnate, and shews that His work for men was a Divine work, accomplished by Him for us only because He was throughout both God and Man, the two natures in Him being inseparable (§§ 7–14). After reaching this conclusion from a general survey of Christ’s life on earth, he examines in the light of it the Arian arguments from isolated words. They assert that Christ refused to be called Good or Master. He refused neither title, and yet declared that both belong to God only (§§ 15–18). And, indeed, He could not have associated Himself more closely than He did with the Father, while yet He kept His Person distinct (§ 19). The Father Himself bears witness to the Son; and the sin and loss of the Jews is this, that, seeing the Father’s works done by Christ, they did not see in Him the Son (§§ 20, 21). The honour and glory of Christ is inseparable from that of God (§§ 22, 23). The Scribe did well to confess the Divine unity, but was still outside the Kingdom because He did not believe in Christ as God (§§ 24–27). Next, the Arian argument from the words, This is life eternal, that they may know Thee, the only true God, and Jesus Christ Whom Thou hast sent, is refuted by comparison with cognate passages (§§ 28–35). For, indeed, if the Father be the only true God, the Son must also be the only true God (§ 36). That Divine nature which is common to Father and Son is subject to no limitations, and the eternal generation can be illustrated by no analogy of created things (§ 37). Christ took humanity, and, since the Father’s nature did not share in this, the unity was so far impaired. But humanity has been raised in Christ to God; and this could only be because His unity in the Divine nature with the Father was perfect. Otherwise the flesh which Christ took could not have entered into the Divine glory (§ 38). There is but one glory of Father and of Son; the Son sought in the Incarnation not glory for the Word but for the flesh (§§ 39, 40). The glory of Father and Son is one; in that unity the Son bestows, as well as receives, glory (§§ 41, 42), and this glory, common to Both, is evidence that the Divine nature also is common to Both (§ 42). Again, the Arians allege the words, The Son can do nothing of Himself, which Hilary shews, by an examination of the context, to be a support of the Catholic cause (§§ 43–46). The Son does the Father’s work, not under compulsion as an inferior, but because They are One. His will is free, yet in perfect harmony with that of the Father, because of their unity of nature (§§ 47–50). The Arians also appeal to the text, The Father is greater than I. The Father is, in fact, greater, first as being the Unbegotten, and secondly inasmuch as the Son has condescended to the state of man, yet without forfeiting His Godhead (§ 51). But He is not greater in nature than the Son, Who is His Image; or rather, the Begetter is the greater, while the Son, as the Begotten, is not less than He, for, although begotten, He had no beginning of existence (§§ 52–57). Next, the allegation of ignorance, based on St. Mark xiii. 32, and therefore of difference in nature from God Omniscient is refuted (§§ 58–62), both by express statements of Scripture and by a consideration of the Divine character. It is only in figurative senses that God is stated in the Old Testament sometimes to come to know, sometimes to be ignorant of, particular facts (§§ 63, 64). And so it is with Christ; His ignorance is but a wise and merciful concealment of knowledge (§§ 65–67). Yet the Arians, though they admit that Christ, being superior to man, knows all the secrets of humanity, assert that He cannot penetrate the mysteries of God (§ 68). But Christ expressly declares that He can and does, for Each is in the Other and is mirrored in the Other (§ 69). The ignorance can be nothing but concealment. Only the Father knows, i.e. He has told none but the Son; the Son does not know, i.e. He wills not to reveal His knowledge (§§ 70, 71). God is unlimited; unlimited therefore in knowledge. The nature of Father and Son being one, it is impossible that the Son should be ignorant of what the Father knows. As in will, so in knowledge, They are One (§§ 72–74). And the Apostles, by repeating their question after the Resurrection, shew that they were aware that His ignorance meant reserve. And Christ did not, this time, speak of ignorance, though He withheld the knowledge which they asked (§ 75).