Today’s Catechism sections address the human nature and attributes of Christ. Supporting material comes from St. Thomas Aquinas’ “Summa Theologica”.

IV. HOW IS THE SON OF GOD MAN?

470 Because "human nature was assumed, not absorbed",97 in the mysterious union of the Incarnation, the Church was led over the course of centuries to confess the full reality of Christ's human soul, with its operations of intellect and will, and of his human body. In parallel fashion, she had to recall on each occasion that Christ's human nature belongs, as his own, to the divine person of the Son of God, who assumed it. Everything that Christ is and does in this nature derives from "one of the Trinity".

The Son of God therefore communicates to his humanity his own personal mode of existence in the Trinity. In his soul as in his body, Christ thus expresses humanly the divine ways of the Trinity:98

The Son of God. . . worked with human hands; he thought with a human mind. He acted with a human will, and with a human heart he loved. Born of the Virgin Mary, he has truly been made one of us, like to us in all things except sin.99

Christ's soul and his human knowledge

471 Apollinarius of Laodicaea asserted that in Christ the divine Word had replaced the soul or spirit. Against this error the Church confessed that the eternal Son also assumed a rational, human soul.100

472 This human soul that the Son of God assumed is endowed with a true human knowledge. As such, this knowledge could not in itself be unlimited: it was exercised in the historical conditions of his existence in space and time. This is why the Son of God could, when he became man, "increase in wisdom and in stature, and in favour with God and man",101 and would even have to inquire for himself about what one in the human condition can learn only from experience.102 This corresponded to the reality of his voluntary emptying of himself, taking "the form of a slave".103

473 But at the same time, this truly human knowledge of God's Son expressed the divine life of his person.104 "The human nature of God's Son, not by itself but by its union with the Word, knew and showed forth in itself everything that pertains to God."105 Such is first of all the case with the intimate and immediate knowledge that the Son of God made man has of his Father.106 The Son in his human knowledge also showed the divine penetration he had into the secret thoughts of human hearts.107

474 By its union to the divine wisdom in the person of the Word incarnate, Christ enjoyed in his human knowledge the fullness of understanding of the eternal plans he had come to reveal.108 What he admitted to not knowing in this area, he elsewhere declared himself not sent to reveal.109

Christ's human will

475 Similarly, at the sixth ecumenical council, Constantinople III in 681, the Church confessed that Christ possesses two wills and two natural operations, divine and human. They are not opposed to each other, but co-operate in such a way that the Word made flesh willed humanly in obedience to his Father all that he had decided divinely with the Father and the Holy Spirit for our salvation.110 Christ's human will "does not resist or oppose but rather submits to his divine and almighty will."111

Christ's true body

476 Since the Word became flesh in assuming a true humanity, Christ's body was finite.112 Therefore the human face of Jesus can be portrayed; at the seventh ecumenical council (Nicaea II in 787) the Church recognized its representation in holy images to be legitimate.113

477 At the same time the Church has always acknowledged that in the body of Jesus "we see our God made visible and so are caught up in love of the God we cannot see."114 The individual characteristics of Christ's body express the divine person of God's Son. He has made the features of his human body his own, to the point that they can be venerated when portrayed in a holy image, for the believer "who venerates the icon is venerating in it the person of the one depicted".115

The heart of the Incarnate Word

478 Jesus knew and loved us each and all during his life, his agony and his Passion, and gave himself up for each one of us: "The Son of God. . . loved me and gave himself for me."116 He has loved us all with a human heart. For this reason, the Sacred Heart of Jesus, pierced by our sins and for our salvation,117 "is quite rightly considered the chief sign and symbol of that. . . love with which the divine Redeemer continually loves the eternal Father and all human beings" without exception.118

IN BRIEF

482 Christ, being true God and true man, has a human intellect and will, perfectly attuned and subject to his divine intellect and divine will, which he has in common with the Father and the Holy Spirit.

483 The Incarnation is therefore the mystery of the wonderful union of the divine and human natures in the one person of the Word.

In his “Summa Theologica” (3, 14), St. Thomas Aquinas addresses the “Defects” of Christ’s human body:

Article 1. Whether the Son of God in human nature ought to have assumed defects of body?

Objection 1. It would seem that the Son of God ought not to have assumed human nature with defects of body. For as His soul is personally united to the Word of God, so also is His body. But the soul of Christ had every perfection, both of grace and truth, as was said above (7, 9; 9, seqq.). Hence, His body also ought to have been in every way perfect, not having any imperfection in it.

Objection 2. Further, the soul of Christ saw the Word of God by the vision wherein the blessed see, as was said above (Question 9, Article 2), and thus the soul of Christ was blessed. Now by the beatification of the soul the body is glorified; since, as Augustine says (Ep. ad Dios. cxviii), "God made the soul of a nature so strong that from the fullness of its blessedness there pours over even into the lower nature" (i.e. the body), "not indeed the bliss proper to the beatific fruition and vision, but the fullness of health" (i.e. the vigor of incorruptibility). Therefore the body of Christ was incorruptible and without any defect.

Objection 3. Further, penalty is the consequence of fault. But there was no fault in Christ, according to 1 Peter 2:22: "Who did no guile." Therefore defects of body, which are penalties, ought not to have been in Him.

Objection 4. Further, no reasonable man assumes what keeps him from his proper end. But by such like bodily defects, the end of Incarnation seems to be hindered in many ways. First, because by these infirmities men were kept back from knowing Him, according to Isaiah 53:2-3: "[There was no sightliness] that we should be desirous of Him. Despised and the most abject of men, a man of sorrows and acquainted with infirmity, and His look was, as it were, hidden and despised, whereupon we esteemed Him not." Secondly, because the de. sire of the Fathers would not seem to be fulfilled, in whose person it is written (Isaiah 51:9): "Arise, arise, put on Thy strength, O Thou Arm of the Lord." Thirdly, because it would seem more fitting for the devil's power to be overcome and man's weakness healed, by strength than by weakness. Therefore it does not seem to have been fitting that the Son of God assumed human nature with infirmities or defects of body.

On the contrary, It is written (Hebrews 2:18): "For in that, wherein He Himself hath suffered and been tempted, He is able to succor them also that are tempted." Now He came to succor us. hence David said of Him (Psalm 120:1): "I have lifted up my eyes to the mountains, from whence help shall come to me." Therefore it was fitting for the Son of God to assume flesh subject to human infirmities, in order to suffer and be tempted in it and so bring succor to us.

I answer that, It was fitting for the body assumed by the Son of God to be subject to human infirmities and defects; and especially for three reasons. First, because it was in order to satisfy for the sin of the human race that the Son of God, having taken flesh, came into the world. Now one satisfies for another's sin by taking on himself the punishment due to the sin of the other. But these bodily defects, to wit, death, hunger, thirst, and the like, are the punishment of sin, which was brought into the world by Adam, according to Romans 5:12: "By one man sin entered into this world, and by sin death." Hence it was useful for the end of Incarnation that He should assume these penalties in our flesh and in our stead, according to Isaiah 53:4, "Surely He hath borne our infirmities." Secondly, in order to cause belief in Incarnation. For since human nature is known to men only as it is subject to these defects, if the Son of God had assumed human nature without these defects, He would not have seemed to be true man, nor to have true, but imaginary, flesh, as the Manicheans held. And so, as is said, Philippians 2:7: "He . . . emptied Himself, taking the form of a servant, being made in the likeness of men, and in habit found as a man." Hence, Thomas, by the sight of His wounds, was recalled to the faith, as related John 20:26. Thirdly, in order to show us an example of patience by valiantly bearing up against human passibility and defects. Hence it is said (Hebrews 12:3) that He "endured such opposition from sinners against Himself, that you be not wearied. fainting in your minds."

Reply to Objection 1. The penalties one suffers for another's sin are the matter, as it were, of the satisfaction for that sin; but the principle is the habit of soul, whereby one is inclined to wish to satisfy for another, and from which the satisfaction has its efficacy, for satisfaction would not be efficacious unless it proceeded from charity, as will be explained (XP, 14, 2). Hence, it behooved the soul of Christ to be perfect as regards the habit of knowledge and virtue, in order to have the power of satisfying; but His body was subject to infirmities, that the matter of satisfaction should not be wanting.

Reply to Objection 2. From the natural relationship which is between the soul and the body, glory flows into the body from the soul's glory. Yet this natural relationship in Christ was subject to the will of His Godhead, and thereby it came to pass that the beatitude remained in the soul, and did not flow into the body; but the flesh suffered what belongs to a passible nature; thus Damascene says (De Fide Orth. iii, 15) that, "it was by the consent of the Divine will that the flesh was allowed to suffer and do what belonged to it."

Reply to Objection 3. Punishment always follows sin actual or original, sometimes of the one punished, sometimes of the one for whom he who suffers the punishment satisfies. And so it was with Christ, according to Isaiah 53:5: "He was wounded for our iniquities, He was bruised for our sins."

Reply to Objection 4. The infirmity assumed by Christ did not impede, but greatly furthered the end of Incarnation, as above stated. And although these infirmities concealed His Godhead, they made known His Manhood, which is the way of coming to the Godhead, according to Romans 5:1-2: "By Jesus Christ we have access to God." Moreover, the ancient Fathers did not desire bodily strength in Christ, but spiritual strength, wherewith He vanquished the devil and healed human weakness.

Footnotes

97 GS 22 # 2.
98 Cf. ⇒ Jn 14:9-10.
99 GS 22 # 2.
100 Cf. Damasus 1: DS 149.
101 ⇒ Lk 2:52.
102 Cf. ⇒ Mk 6 38; ⇒ 8 27; ⇒ Jn 11:34; etc.
103 ⇒ Phil 2:7.
104 Cf. St. Gregory the Great, "Sicut aqua" ad Eulogium, Epist. Lib. 10, 39 PL 77, 1097 Aff.; DS 475.
105 St. Maximus the Confessor, Qu. et dub. 66 PG 90, 840A.
106 Cf. ⇒ Mk 14:36; ⇒ Mt 11:27; ⇒ Jn 1:18; 8:55; etc.
107 Cf. ⇒ Mk 2:8; ⇒ Jn 2 25; ⇒ 6:61; etc.
108 Cf. ⇒ Mk 8:31; ⇒ 9:31; ⇒ 10:33-34; ⇒ 14:18-20, ⇒ 26-30.
109 Cf. ⇒ Mk 13:32, ⇒ Acts 1:7.
110 Cf. Council of Constantinople III (681): DS 556-559.
111 Council of Constantinople III: DS 556.
112 Cf. Council of the Lateran (649): DS 504.
113 Cf. Cal 3:1; cf. Council of Nicaea II (787): DS 600-603.
114 Roman Missal, Preface of Christmas I.
115 Council of Nicaea II: DS 601.
116 Cal 2:20.
117 Cf. ⇒ Jn 19:34.
118 Pius XII, Enc. Haurietis aquas (1956): DS 3924; cf. DS 3812.