Summa Th. III EN Qu.7 a.12
Objection: 1. It would seem that the grace of Christ could increase. For to every finite thing addition can be made. But the grace of Christ was finite. Therefore it could increase.
2. Further, it is by Divine power that grace is increased, according to 2Co 9,8: "And God is able to make all grace abound in you." But the Divine power, being infinite, is confined by no limits. Therefore it seems that the grace of Christ could have been greater.
3. Further, it is written (Lc 2,52) that the child "Jesus advanced in wisdom and age and grace with God and men." Therefore the grace of Christ could increase.
On the contrary It is written (Jn 1,14): "We saw Him [Vulg.: 'His glory'] as it were . . . the Only-begotten of the Father, full of grace and truth." But nothing can be or can be thought greater than that anyone should be the Only-begotten of the Father. Therefore no greater grace can be or can be thought than that of which Christ was full.
I answer that For a form to be incapable of increase happens in two ways: First on the part of the subject; secondly, on the part of the form itself. On the part of the subject, indeed, when the subject reaches the utmost limit wherein it partakes of this form, after its own manner, e.g. if we say that air cannot increase in heat, when it has reached the utmost limit of heat which can exist in the nature of air, although there may be greater heat in actual existence, viz. the heat of fire. But on the part of the form, the possibility of increase is excluded when a subject reaches the utmost perfection which this form can have by nature, e.g. if we say the heat of fire cannot be increased because there cannot be a more perfect grade of heat than that to which fire attains. Now the proper measure of grace, like that of other forms, is determined by the Divine wisdom, according to Sg 11,21: "Thou hast ordered all things in number, weight and measure." And it is with reference to its end that a measure is set to every form. as there is no greater gravity than that of the earth, because there is no lower place than that of the earth. Now the end of grace is the union of the rational creature with God. But there can neither be nor be thought a greater union of the rational creature with God than that which is in the Person. And hence the grace of Christ reached the highest measure of grace. Hence it is clear that the grace of Christ cannot be increased on the part of grace. But neither can it be increased on the part of the subject, since Christ as man was a true and full comprehensor from the first instant of His conception. Hence there could have been no increase of grace in Him, as there could be none in the rest of the blessed, whose grace could not increase, seeing that they have reached their last end. But as regards men who are wholly wayfarers, their grace can be increased not merely on the part of the form, since they have not attained the highest degree of grace, but also on the part of the subject, since they have not yet attained their end.
Reply to Objection: 1. If we speak of mathematical quantity, addition can be made to any finite quantity, since there is nothing on the part of finite quantity which is repugnant to addition. But if we speak of natural quantity, there may be repugnance on the part of the form to which a determined quantity is due, even as other accidents are determined. Hence the Philosopher says (De Anima ii, 41) that "there is naturally a term of all things, and a fixed limit of magnitude and increase." And hence to the quantity of the whole there can be no addition. And still more must we suppose a term in the forms themselves, beyond which they may not go. Hence it is not necessary that addition should be capable of being made to Christ's grace, although it is finite in its essence.
2. Although the Divine power can make something greater and better than the habitual grace of Christ, yet it could not make it to be ordained to anything greater than the personal union with the Only-begotten Son of the Father; and to this union, by the purpose of the Divine wisdom, the measure of grace is sufficient.
3. Anyone may increase in wisdom and grace in two ways. First inasmuch as the very habits of wisdom and grace are increased; and in this way Christ did not increase. Secondly, as regards the effects, i.e. inasmuch as they do wiser and greater works; and in this way Christ increased in wisdom and grace even as in age, since in the course of time He did more perfect works, to prove Himself true man, both in the things of God, and in the things of man.
Objection: 1. It would seem that the habitual grace did not follow after the union. For nothing follows itself. But this habitual grace seems to be the same as the grace of union; for Augustine says (De Praedest. Sanct. xv): "Every man becomes a Christian from the beginning of his belief, by the same grace whereby this Man from His beginning became Christ"; and of these two the first pertains to habitual grace and the second to the grace of union. Therefore it would seem that habitual grace did not follow upon the union.
2. Further, disposition precedes perfection, if not in time, at least in thought. But the habitual grace seems to be a disposition in human nature for the personal union. Therefore it seems that the habitual grace did not follow but rather preceded the union.
3. Further, the common precedes the proper. But habitual grace is common to Christ and other men; and the grace of union is proper to Christ. Therefore habitual grace is prior in thought to the union. Therefore it does not follow it.
On the contrary It is written (Is 42,1): "Behold my servant, I will uphold Him . . . "and farther on: "I have given My Spirit upon Him"; and this pertains to the gift of habitual grace. Hence it remains that the assumption of human nature to the unity of the Person preceded the habitual grace of Christ.
I answer that The union of the human nature with the Divine Person, which, as we have said above (Question , Article ; Question , Article ), is the grace of union, precedes the habitual grace of Christ, not in order of time, but by nature and in thought; and this for a triple reason: First, with reference to the order of the principles of both. For the principle of the union is the Person of the Son assuming human nature, Who is said to be sent into the world, inasmuch as He assumed human nature; but the principle of habitual grace, which is given with charity, is the Holy Ghost, Who is said to be sent inasmuch as He dwells in the mind by charity. Now the mission of the Son is prior, in the order of nature, to the mission of the Holy Ghost, even as in the order of nature the Holy Ghost proceeds from the Son, and love from wisdom. Hence the personal union, according to which the mission of the Son took place, is prior in the order of nature to habitual grace, according to which the mission of the Holy Ghost takes place. Secondly, the reason of this order may be taken from the relation of grace to its cause. For grace is caused in man by the presence of the Godhead, as light in the air by the presence of the sun. Hence it is written (Ez 43,2): "The glory of the God of Israel came in by the way of the east . . . and the earth shone with His majesty." But the presence of God in Christ is by the union of human nature with the Divine Person. Hence the habitual grace of Christ is understood to follow this union, as light follows the sun. Thirdly, the reason of this union can be taken from the end of grace, since it is ordained to acting rightly, and action belongs to the suppositum and the individual. Hence action and, in consequence, grace ordaining thereto, presuppose the hypostasis which operates. Now the hypostasis did not exist in the human nature before the union, as is clear from Question , Article . Therefore the grace of union precedes, in thought, habitual grace.
Reply to Objection: 1. Augustine here means by grace the gratuitous will of God, bestowing benefits gratis; and hence every man is said to be made a Christian by the same grace whereby a Man became Christ, since both take place by the gratuitous will of God without merits.
2. As disposition in the order of generation precedes the perfection to which it disposes, in such things as are gradually perfected; so it naturally follows the perfection which one has already obtained; as heat, which was a disposition to the form of fire, is an effect flowing from the form of already existing fire. Now the human nature in Christ is united to the Person of the Word from the beginning without succession. Hence habitual grace is not understood to have preceded the union, but to have followed it; as a natural property. Hence, as Augustine says (Enchiridion xl): "Grace is in a manner natural to the Man Christ."
3. The common precedes the proper, when both are of the same genus; but when they are of divers genera, there is nothing to prevent the proper being prior to the common. Now the grace of union is not in the same genus as habitual grace; but is above all genera even as the Divine Person Himself. Hence there is nothing to prevent this proper from being before the common since it does not result from something being added to the common, but is rather the principle and source of that which is common.
We must now consider the grace of Christ as the Head of the Church; and under this head there are eight points of inquiry:
(1) Whether Christ is the Head of the Church?
(2) Whether He is the Head of men as regards their bodies or only as regards their souls?
(3) Whether He is the Head of all men?
(4) Whether He is the Head of the angels?
(5) Whether the grace of Christ as Head of the Church is the same as His habitual grace as an individual man?
(6) Whether to be Head of the Church is proper to Christ?
(7) Whether the devil is the head of all the wicked?
(8) Whether Anti-christ can be called the head of all the wicked?
Objection: 1. It would seem that it does not belong to Christ as man to be Head of the Church. For the head imparts sense and motion to the members. Now spiritual sense and motion which are by grace, are not imparted to us by the Man Christ, because, as Augustine says (De Trin. i, 12; xv, 24), "not even Christ, as man, but only as God, bestows the Holy Ghost." Therefore it does not belong to Him as man to be Head of the Church.
2. Further, it is not fitting for the head to have a head. But God is the Head of Christ, as man, according to 1Co 11,3, "The Head of Christ is God." Therefore Christ Himself is not a head.
3. Furthermore, the head of a man is a particular member, receiving an influx from the heart. But Christ is the universal principle of the whole Church. Therefore He is not the Head of the Church.
On the contrary It is written (Ep 1,22): "And He . . . hath made Him head over all the Church."
I answer that As the whole Church is termed one mystic body from its likeness to the natural body of a man, which in divers members has divers acts, as the Apostle teaches (Rm 12 1Co 12), so likewise Christ is called the Head of the Church from a likeness with the human head, in which we may consider three things, viz. order, perfection, and power: "Order," indeed; for the head is the first part of man, beginning from the higher part; and hence it is that every principle is usually called a head according to Ez 16,25: "At every head of the way, thou hast set up a sign of thy prostitution"---"Perfection," inasmuch as in the head dwell all the senses, both interior and exterior, whereas in the other members there is only touch, and hence it is said (Is 9,15): "The aged and honorable, he is the head"---"Power," because the power and movement of the other members, together with the direction of them in their acts, is from the head, by reason of the sensitive and motive power there ruling; hence the ruler is called the head of a people, according to 1S 15,17: "When thou wast a little one in thy own eyes, wast thou not made the head of the tribes of Israel?" Now these three things belong spiritually to Christ. First, on account of His nearness to God His grace is the highest and first, though not in time, since all have received grace on account of His grace, according to Rm 8,29: "For whom He foreknew, He also predestinated to be made conformable to the image of His Son; that He might be the first-born amongst many brethren." Secondly, He had perfection as regards the fulness of all graces, according to Jn 1,14, "We saw Him [Vulg.: 'His glory'] . . . full of grace and truth," as was shown, Question , Article . Thirdly, He has the power of bestowing grace on all the members of the Church, according to Jn 1,16: "Of His fulness we have all received." And thus it is plain that Christ is fittingly called the Head of the Church.
Reply to Objection: 1. To give grace or the Holy Ghost belongs to Christ as He is God, authoritatively; but instrumentally it belongs also to Him as man, inasmuch as His manhood is the instrument of His Godhead. And hence by the power of the Godhead His actions were beneficial, i.e. by causing grace in us, both meritoriously and efficiently. But Augustine denies that Christ as man gives the Holy Ghost authoritatively. Even other saints are said to give the Holy Ghost instrumentally, or ministerially, according to Ga 3,5: "He . . . who giveth to you the Spirit."
2. In metaphorical speech we must not expect a likeness in all respects; for thus there would be not likeness but identity. Accordingly a natural head has not another head because one human body is not part of another; but a metaphorical body, i.e. an ordered multitude, is part of another multitude as the domestic multitude is part of the civil multitude; and hence the father who is head of the domestic multitude has a head above him, i.e. the civil governor. And hence there is no reason why God should not be the Head of Christ, although Christ Himself is Head of the Church.
3. The head has a manifest pre-eminence over the other exterior members; but the heart has a certain hidden influence. And hence the Holy Ghost is likened to the heart, since He invisibly quickens and unifies the Church; but Christ is likened to the Head in His visible nature in which man is set over man.
Objection: 1. It would seem that Christ is not the Head of men as to their bodies. For Christ is said to be the Head of the Church inasmuch as He bestows spiritual sense and the movement of grace on the Church. But a body is not capable of this spiritual sense and movement. Therefore Christ is not the Head of men as regards their bodies.
2. Further, we share bodies with the brutes. If therefore Christ was the Head of men as to their bodies, it would follow that He was the Head of brute animals; and this is not fitting.
3. Further, Christ took His body from other men, as is clear from Mt 1 and Lc 3. But the head is the first of the members, as was said above (Article , ad 3). Therefore Christ is not the Head of the Church as regards bodies.
On the contrary It is written (Ph 3,21): "Who will reform the body of our lowness, made like to the body of His glory."
I answer that The human body has a natural relation to the rational soul, which is its proper form and motor. Inasmuch as the soul is its form, it receives from the soul life and the other properties which belong specifically to man; but inasmuch as the soul is its motor, the body serves the soul instrumentally. Therefore we must hold that the manhood of Christ had the power of "influence," inasmuch as it is united to the Word of God, to Whom His body is united through the soul, as stated above (Question , Article ). Hence the whole manhood of Christ, i.e. according to soul and body, influences all, both in soul and body; but principally the soul, and secondarily the body: First, inasmuch as the "members of the body are presented as instruments of justice" in the soul that lives through Christ, as the Apostle says (Rm 6,13): secondly, inasmuch as the life of glory flows from the soul on to the body, according to Rm 8,11: "He that raised up Jesus from the dead shall quicken also your mortal bodies, because of His Spirit that dwelleth in you."
Reply to Objection: 1. The spiritual sense of grace does not reach to the body first and principally, but secondarily and instrumentally, as was said above.
2. The body of an animal has no relation to a rational soul, as the human body has. Hence there is no parity.
3. Although Christ drew the matter of His body from other men, yet all draw from Him the immortal life of their body, according to 1Co 15,22: "And as in Adam all die, so also in Christ all shall be made alive."
Objection: 1. It would seem that Christ is not the Head of all men. For the head has no relation except to the members of its body. Now the unbaptized are nowise members of the Church which is the body of Christ, as it is written (Ep 1,23). Therefore Christ is not the Head of all men.
2. Further, the Apostle writes to the Ephesians (Ep 5,25 Ep 5,27): "Christ delivered Himself up for" the Church "that He might present it to Himself a glorious Church, not having spot or wrinkle or any such thing." But there are many of the faithful in whom is found the spot or the wrinkle of sin. Therefore Christ is not the Head of all the faithful.
3. Further, the sacraments of the Old Law are compared to Christ as the shadow to the body, as is written (Col 2,17). But the fathers of the Old Testament in their day served unto these sacraments, according to He 8,5: "Who serve unto the example and shadow of heavenly things." Hence they did not pertain to Christ's body, and therefore Christ is not the Head of all men.
On the contrary It is written (1Tm 4,10): "Who is the Saviour of all men, especially of the faithful," and (1Jn 2,2): "He is the propitiation for our sins, and not for ours only, but also for those of the whole world." Now to save men and to be a propitiation for their sins belongs to Christ as Head. Therefore Christ is the Head of all men.
I answer that This is the difference between the natural body of man and the Church's mystical body, that the members of the natural body are all together, and the members of the mystical are not all together---neither as regards their natural being, since the body of the Church is made up of the men who have been from the beginning of the world until its end---nor as regards their supernatural being, since, of those who are at any one time, some there are who are without grace, yet will afterwards obtain it, and some have it already. We must therefore consider the members of the mystical body not only as they are in act, but as they are in potentiality. Nevertheless, some are in potentiality who will never be reduced to act, and some are reduced at some time to act; and this according to the triple class, of which the first is by faith, the second by the charity of this life, the third by the fruition of the life to come. Hence we must say that if we take the whole time of the world in general, Christ is the Head of all men, but diversely. For, first and principally, He is the Head of such as are united to Him by glory; secondly, of those who are actually united to Him by charity; thirdly, of those who are actually united to Him by faith; fourthly, of those who are united to Him merely in potentiality, which is not yet reduced to act, yet will be reduced to act according to Divine predestination; fifthly, of those who are united to Him in potentiality, which will never be reduced to act; such are those men existing in the world, who are not predestined, who, however, on their departure from this world, wholly cease to be members of Christ, as being no longer in potentiality to be united to Christ.
Reply to Objection: 1. Those who are unbaptized, though not actually in the Church, are in the Church potentially. And this potentiality is rooted in two things---first and principally, in the power of Christ, which is sufficient for the salvation of the whole human race; secondly, in free-will.
2. To be "a glorious Church not having spot or wrinkle" is the ultimate end to which we are brought by the Passion of Christ. Hence this will be in heaven, and not on earth, in which "if we say we have no sin, we deceive ourselves," as is written (1Jn 1,8). Nevertheless, there are some, viz. mortal, sins from which they are free who are members of Christ by the actual union of charity; but such as are tainted with these sins are not members of Christ actually, but potentially; except, perhaps, imperfectly, by formless faith, which unites to God, relatively but not simply, viz. so that man partake of the life of grace. For, as is written (Jc 2,20): "Faith without works is dead." Yet such as these receive from Christ a certain vital act, i.e. to believe, as if a lifeless limb were moved by a man to some extent.
3. The holy Fathers made use of the legal sacraments, not as realities, but as images and shadows of what was to come. Now it is the same motion to an image as image, and to the reality, as is clear from the Philosopher (De Memor. et Remin. ii). Hence the ancient Fathers, by observing the legal sacraments, were borne to Christ by the same faith and love whereby we also are borne to Him, and hence the ancient Fathers belong to the same Church as we.
Objection: 1. It would seem that Christ as man is not the head of the angels. For the head and members are of one nature. But Christ as man is not of the same nature with the angels, but only with men, since, as is written (He 2,16): "For nowhere doth He take hold of the angels, but of the seed of Abraham He taketh hold." Therefore Christ as man is not the head of the angels.
2. Further, Christ is the head of such as belong to the Church, which is His Body, as is written (Ep 1,23). But the angels do not belong to the Church. For the Church is the congregation of the faithful: and in the angels there is no faith, for they do not "walk by faith" but "by sight," otherwise they would be "absent from the Lord," as the Apostle argues (2Co 5,6-7). Therefore Christ as man is not head of the angels.
3. Further, Augustine says (Tract. xix; xxiii in Joan.), that as "the Word" which "was in the beginning with the Father" quickens souls, so the "Word made flesh" quickens bodies, which angels lack. But the Word made flesh is Christ as man. Therefore Christ as man does not give life to angels, and hence as man He is not the head of the angels.
On the contrary The Apostle says (Col 2,10), "Who is the head of all Principality and Power," and the same reason holds good with the other orders of angels. Therefore Christ is the Head of the angels.
I answer that As was said above (Article , ad 2), where there is one body we must allow that there is one head. Now a multitude ordained to one end, with distinct acts and duties, may be metaphorically called one body. But it is manifest that both men and angels are ordained to one end, which is the glory of the Divine fruition. Hence the mystical body of the Church consists not only of men but of angels. Now of all this multitude Christ is the Head, since He is nearer God, and shares His gifts more fully, not only than man, but even than angels; and of His influence not only men but even angels partake, since it is written (Ep 1,20-22): that God the Father set "Him," namely Christ, "on His right hand in the heavenly places, above all Principality and Power and Virtue and Dominion and every name that is named not only in this world, but also in that which is to come. And He hath subjected all things under His feet." Therefore Christ is not only the Head of men, but of angels. Hence we read (Mt 4,11) that "angels came and ministered to Him."
Reply to Objection: 1. Christ's influence over men is chiefly with regard to their souls; wherein men agree with angels in generic nature, though not in specific nature. By reason of this agreement Christ can be said to be the Head of the angels, although the agreement falls short as regards the body.
2. The Church, on earth, is the congregation of the faithful; but, in heaven, it is the congregation of comprehensors. Now Christ was not merely a wayfarer, but a comprehensor. And therefore He is the Head not merely of the faithful, but of comprehensors, as having grace and glory most fully.
3. Augustine here uses the similitude of cause and effect, i.e. inasmuch as corporeal things act on bodies, and spiritual things on spiritual things. Nevertheless, the humanity of Christ, by virtue of the spiritual nature, i.e. the Divine, can cause something not only in the spirits of men, but also in the spirits of angels, on account of its most close conjunction with God, i.e. by personal union.
Objection: 1. It would seem that the grace whereby Christ is Head of the Church and the individual grace of the Man are not the same. For the Apostle says (Rm 5,15): "If by the offense of one many died, much more the grace of God and the gift, by the grace of one man, Jesus Christ, hath abounded unto many." But the actual sin of Adam is distinct from original sin which he transmitted to his posterity. Hence the personal grace which is proper to Christ is distinct from His grace, inasmuch as He is the Head of the Church, which flows to others from Him.
2. Further, habits are distinguished by acts. But the personal grace of Christ is ordained to one act, viz. the sanctification of His soul; and the capital grace is ordained to another, viz. to sanctifying others. Therefore the personal grace of Christ is distinct from His grace as He is the Head of the Church.
3. Further, as was said above (Question , Article ), in Christ we distinguish a threefold grace, viz. the grace of union, capital grace, and the individual grace of the Man. Now the individual grace of Christ is distinct from the grace of union. Therefore it is also distinct from the capital grace.
On the contrary It is written (Jn 1,16): "Of His fulness we all have received." Now He is our Head, inasmuch as we receive from Him. Therefore He is our Head, inasmuch as He has the fulness of grace. Now He had the fulness of grace, inasmuch as personal grace was in Him in its perfection, as was said above (Question , Article ). Hence His capital and personal grace are not distinct.
I answer that Since everything acts inasmuch as it is a being in act, it must be the same act whereby it is in act and whereby it acts, as it is the same heat whereby fire is hot and whereby it heats. Yet not every act whereby anything is in act suffices for its being the principle of acting upon others. For since the agent is nobler than the patient, as Augustine says (Gn ad lit. xii, 16) and the Philosopher (De Anima iii, 19), the agent must act on others by reason of a certain pre-eminence. Now it was said above (Article ; Question , Article ) grace was received by the soul of Christ in the highest way; and therefore from this pre-eminence of grace which He received, it is from Him that this grace is bestowed on others---and this belongs to the nature of head. Hence the personal grace, whereby the soul of Christ is justified, is essentially the same as His grace, as He is the Head of the Church, and justifies others; but there is a distinction of reason between them.
Reply to Objection: 1. Original sin in Adam, which is a sin of the nature, is derived from his actual sin, which is a personal sin, because in him the person corrupted the nature; and by means of this corruption the sin of the first man is transmitted to posterity, inasmuch as the corrupt nature corrupts the person. Now grace is not vouchsafed us by means of human nature, but solely by the personal action of Christ Himself. Hence we must not distinguish a twofold grace in Christ, one corresponding to the nature, the other to the person as in Adam we distinguish the sin of the nature and of the person.
2. Different acts, one of which is the reason and the cause of the other, do not diversify a habit. Now the act of the personal grace which is formally to sanctify its subject, is the reason of the justification of others, which pertains to capital grace. Hence it is that the essence of the habit is not diversified by this difference.
3. Personal and capital grace are ordained to an act; but the grace of union is not ordained to an act, but to the personal being. Hence the personal and the capital grace agree in the essence of the habit; but the grace of union does not, although the personal grace can be called in a manner the grace of union, inasmuch as it brings about a fitness for the union; and thus the grace of union, the capital, and the personal grace are one in essence, though there is a distinction of reason between them.
Objection: 1. It seems that it is not proper to Christ to be Head of the Church. For it is written (1S 15,17): "When thou wast a little one in thy own eyes, wast thou not made the head of the tribes of Israel?" Now there is but one Church in the New and the Old Testament. Therefore it seems that with equal reason any other man than Christ might be head of the Church.
2. Further, Christ is called Head of the Church from His bestowing grace on the Church's members. But it belongs to others also to grant grace to others, according to Ep 4,29: "Let no evil speech proceed from your mouth; but that which is good to the edification of faith, that it may administer grace to the hearers." Therefore it seems to belong also to others than Christ to be head of the Church.
3. Further, Christ by His ruling over the Church is not only called "Head," but also "Shepherd" and "Foundation." Now Christ did not retain for Himself alone the name of Shepherd, according to 1P 5,4, "And when the prince of pastors shall appear, you shall receive a never-fading crown of glory"; nor the name of Foundation, according to Apoc. 21:14: "And the wall of the city had twelve foundations." Therefore it seems that He did not retain the name of Head for Himself alone.
On the contrary It is written (Col 2,19): "The head" of the Church is that "from which the whole body, by joints and bands being supplied with nourishment and compacted groweth unto the increase of God." But this belongs only to Christ. Therefore Christ alone is Head of the Church.
I answer that The head influences the other members in two ways. First, by a certain intrinsic influence, inasmuch as motive and sensitive force flow from the head to the other members; secondly, by a certain exterior guidance, inasmuch as by sight and the senses, which are rooted in the head, man is guided in his exterior acts. Now the interior influx of grace is from no one save Christ, Whose manhood, through its union with the Godhead, has the power of justifying; but the influence over the members of the Church, as regards their exterior guidance, can belong to others; and in this way others may be called heads of the Church, according to Amos 6:1, "Ye great men, heads of the people"; differently, however, from Christ. First, inasmuch as Christ is the Head of all who pertain to the Church in every place and time and state; but all other men are called heads with reference to certain special places, as bishops of their Churches. Or with reference to a determined time as the Pope is the head of the whole Church, viz. during the time of his Pontificate, and with reference to a determined state, inasmuch as they are in the state of wayfarers. Secondly, because Christ is the Head of the Church by His own power and authority; while others are called heads, as taking Christ's place, according to 2Co 2,10, "For what I have pardoned, if I have pardoned anything, for your sakes I have done it in the person of Christ," and 2Co 5,20, "For Christ therefore we are ambassadors, God, as it were, exhorting by us."
Reply to Objection: 1. The word "head" is employed in that passage in regard to exterior government; as a king is said to be the head of his kingdom.
2. Man does not distribute grace by interior influx, but by exteriorly persuading to the effects of grace.
3. As Augustine says (Tract. xlvi in Joan.): "If the rulers of the Church are Shepherds, how is there one Shepherd, except that all these are members of one Shepherd?" So likewise others may be called foundations and heads, inasmuch as they are members of the one Head and Foundation. Nevertheless, as Augustine says (Tract. xlvii), "He gave to His members to be shepherds; yet none of us calleth himself the Door. He kept this for Himself alone." And this because by door is implied the principal authority, inasmuch as it is by the door that all enter the house; and it is Christ alone by "Whom also we have access . . . into this grace, wherein we stand" (Rm 5,2); but by the other names above-mentioned there may be implied not merely the principal but also the secondary authority.
Summa Th. III EN Qu.7 a.12