Thomas Aquinas, Disputed Questions on Truth (De Veritate)

1. The Apostle in writing to the Colossians (1:19) places the headship in Christ "because in him, it hath well pleased the Father that all fullness should dwell," as appears in the passage quoted above. But all the fullness of the divinity dwells in Christ from the union. Besides the union, then, no grace is required for Him to be the head.

2. Christ is the head of the Church in so far as He works for our salvation. But, as Damascene says, the action of His humanity conferred salvation upon us inasmuch as the humanity was in a way "the instrument of the divinity." Now since an instrument does not require any habit but moves only when moved by the principal agent, it seems that Christ did not require habitual grace in order to be the head.

3. The action of one man can contribute to the salvation of another in two ways: (1) Inasmuch as he acts as an individual person. Then grace is required in order that his action may be meritorious for himself or for another. (2) As a person representing the community. This applies to the ministers of the Church, who work for the salvation of others by administering the sacraments and pouring forth prayers to God in the name of the Church. No grace is needed for this but only a power or state, for such actions are performed not only by good but also by wicked men. Now Christ as head of the Church is considered as a person representing the community, and all the ministers of the Church are His vicars. He therefore had no need of habitual grace in order to be the head.

4. Christ was the head of the Church because His merit was infinite. Thus He was able to exercise an influence upon all the members of the Church and wipe out their sins. But He did not get the infinity of His merit from habitual grace, which was finite. Christ was therefore not the head by reason of any habitual grace.

5. Christ is the head of the Church inasmuch as He is the "mediator of God and man" (I Timothy 2:5). But He is the mediator of God and man inasmuch as He is intermediate between God and men, having divinity with God and humanity with men. Now this comes from the union. Consequently the union alone without habitual grace is enough for the headship.

6. One subject has one life. But grace is the life of the soul. In one soul there is therefore one grace; and so in Christ besides the grace which is His as an individual person there is not required any other habitual grace by which He is the head.

7. Christ is the head because He influences the members of the Church. But no matter how much grace He had, He could not influence them unless He were God and man. Consequently no habitual grace by which He is the head is required, but He has this position from the union alone.

To the Contrary:

1'. There are the words of John (1:16): "Of His fullness we all have received: and grace for grace." Thus He had some grace by which He in turn poured out grace upon us.

2'. The head of the Mystical Body has some resemblance to the head of a physical body. But for the perfection of a physical body it is required that the power of sensation be in the head most fully in order that it can communicate sensation to the members. In Christ too, then, for Him to be the head the fullness of grace is required.

3'. Dionysius says that those who have the office of enlightening, perfecting, and cleansing others first have light, cleanness, and perfection themselves. But as head of the Church Christ cleanses, enlightens, and perfects. In order to be the head, therefore, He must have the fullness of grace, by which He is pure, full of light, and perfect.

REPLY:

As Damascene says, the humanity of Christ in some sense "was the instrument of the divinity"; and for this reason His actions could be salutary for us. Inasmuch as it was the instrument of the divinity, then, it had to have a special connection with the divinity.

The closer a substance stands to the goodness of God, the more fully it participates in His goodness, as Dionysius makes clear. Consequently the humanity of Christ also, because it is connected with the divinity more closely than the others and in a more special way, has participated in the divine goodness through the gift of grace in a more excellent way.

As a result there was a fitness in this humanity not only to have grace but also to communicate it to other beings, as the most shining bodies transmit the light of the sun to others. And because in some sense Christ communicates the effects of grace to all rational creatures, this is why He is in some sense the source of all grace in His humanity, just as God is the source of all being. Then, as all the perfection of being is united in God, in Christ the fullness of all grace and virtue is found, and because of it He not only is capable of the work of grace Himself but can bring others to grace. For this reason He has the headship.

In a physical head there is not only the power of sensing, in order that it may sense by sight, hearing, and touch and such senses; but this power is in it in such a way that it is the root from which sensation flows into all the other members. In Christ, accordingly, one and the same habitual grace is called the grace of union as befitting a nature united to the divinity, and the grace of headship as the means by which grace is communicated to others for their salvation, and also the grace of an individual person as perfecting Him for meritorious works.

Answers to Difficulties:

1. In Christ two different kinds of fullness are referred to: one, of the divinity, according to which Christ is fully God; and the other, of grace, according to which He is said to be full of grace and truth. It is of this latter fullness that the Apostle speaks in Colossians 1:18-20, and of the former in Colossians 2:9. The second is derived from the first and by it the grace of headship is formally constituted.

2. An inanimate instrument such as an ax does not need a habit; but an animate instrument such as a servant does. The human nature in Christ is such an instrument.

3. A minister of the Church does not act in the sacraments by his own power but by the power of another, that is, Christ. The minister accordingly does not need personal grace but only the authority of orders, by which he is constituted the vicar of Christ. But Christ wrought our salvation by His own power. The fullness of grace was therefore necessary in Him.

4. Although Christ's merit has a certain infinity from the dignity of the person, it gets its meritoriousness from habitual grace, without which there cannot be any merit.

5. Christ is the mediator between God and men even in His human nature, in so far as He has passibility together with men, and justice together with God. But His justice is in Him by means of grace. For this reason besides the union there is required habitual grace in Christ in order that He may be the mediator and the head.

6. One and the same habitual grace is from different points of view the grace of the head, the grace of an individual person, and the grace of union, as was explained above.*

7. Although both natures are required in Christ for Him to be the head, from the union of the divine nature with the human there results in the human nature a certain fullness of grace, which issues in an overflow from Christ the head into others.