MYSTICI CORPORIS CHRISTI
ENCYCLICAL OF POPE PIUS XII
ON THE MISTICAL BODY OF CHRIST
TO OUR VENERABLE BRETHREN, PATRIARCHS, PRIMATES,
ARCHBISHOPS, BISHIOPS, AND OTHER LOCAL ORDINARIES
ENJOYING PEACE AND COMMUNION WITH THE APOSTOLIC SEE
Health and Apostolic Benediction.
The doctrine of the Mystical Body of Christ, which is the Church, was first
taught us by the Redeemer Himself. Illustrating as it does the great and inestimable privilege of our intimate union with so exalted a Head, this doctrine by its sublime dignity invites all those who are drawn by the
Holy Spirit to study it, and gives them, in the truths of which it proposes to the mind, a strong incentive to the performance of such good works as are conformable to its teaching. For this reason, We deem it fitting
to speak to you on this subject through this Encyclical Letter, developing and explaining above all, those points which concern the Church Militant. To this We are urged not only by the surpassing grandeur of the
subject but also by the circumstances of the present time.
2. For We intend to speak of the riches stored up in this Church which Christ purchased with His own Blood,  and whose members glory in a thorn-crowned
Head. The fact that they thus glory is a striking proof that the greatest joy and exaltation are born only of suffering, and hence that we should rejoice if we partake of the sufferings of Christ, that when His glory
shall be revealed we may also be glad with exceeding joy. 
3. From the outset it should be noted that the society established by the Redeemer of the human race resembles its divine Founder, who was persecuted,
calumniated and tortured by those very men whom He had undertaken to save. We do not deny, rather from a heart filled with gratitude to God We admit, that even in our turbulent times there are many who, though outside
the fold of Jesus Christ, look to the Church as the only haven of salvation; but We are also aware that the Church of God not only is despised and hated maliciously by those who shut their eyes to the light of Christian
wisdom and miserably return to the teachings, customs and practices of ancient paganism, but is ignored and neglected, and even at times looked upon as irksome by many Christians who are allured by specious error or
caught in the meshes of the world's corruption. In obedience, therefore, Venerable Brethren, to the voice of Our conscience and in compliance with the wishes of many, We will set forth before the eyes of all and extol
the beauty, the praises, and the glory of Mother Church to whom, after God, we owe everything.
4. And it is to be hoped that Our instructions and exhortations will bring forth abundant fruit in the souls of the
faithful in the present circumstances. For We know that if all the sorrows and calamities of these stormy times, by which countless multitudes are being sorely tried, are accepted from God's hands with calm submission,
they naturally lift souls above the passing things of earth those of heaven that abide forever, and arouse a certain secret thirst and intense desire for spiritual things. Thus, urged by the Holy Spirit, men are moved,
and as it were, impelled to seek the kingdom of God with greater diligence; for the more they are detached from the vanities of this world and from inordinate love of temporal things, the more apt they will be to
perceive the light of heavenly mysteries. But the vanity and emptiness of earthly things are more manifest today than perhaps at any other period, when Kingdoms and States are crumbling, when enormous quantities of
goods and all kinds of wealth are being sunk in the depths of the sea, and cities, towns and fertile fields are strewn with massive ruins and defiled with the blood of brothers.
5. Moreover, We trust that Our
exposition of the doctrine of the Mystical Body of Christ will be acceptable and useful to those also who are without the fold of the Church, not only because their good will toward the Church seems to grow from day to
day, but also because, while before their eyes nation rises up against nation, kingdom against kingdom, and discord is sown everywhere together with the seeds of envy and hatred, if they turn their gaze to the Church,
if they contemplate her divinely-given unity - by which all men of every race are united to Christ in the bond of brotherhood - they will be forced to admire this fellowship in charity, and with the guidance and
assistance of divine grace will long to share in the same union and charity.
6. There is a special reason too, and one most dear to Us, which recalls this doctrine to Our mind and with it a deep sense of joy. During
the year that has passed since the twenty-fifth anniversary of Our Episcopal consecration, We have had the great consolation of witnessing something that has made the image of the Mystical Body of Jesus Christ stand out
most clearly before the whole world. Though a long and deadly war has pitilessly broken the bond of brotherly union between nations, We have seen Our children in Christ, in whatever part of the world they happened to
be, one in will and affection, lift up their hearts to the common Father, who, carrying in his own heart the cares and anxieties of all, is guiding the barque of the Catholic Church int he teeth of a raging tempest.
This is a testimony to the wonderful union existing among Christians; but it also proves that, as Our paternal love embraces all peoples, whatever their nationality and race, so Catholics the world over, though their
countries may have drawn the sword against each other, look to the Vicar of Jesus Christ as to the loving Father of them all, who, with absolute impartiality and incorruptible judgment, rising above the conflicting
gales of human passions, takes upon himself with all his strength the defence of truth, justice and charity.
7. We have been no less consoled to know that with spontaneous generosity a fund has been created for the
erection of a church in Rome to be dedicated to our saintly predecessor and patron, Eugene I. At this temple, to be built by the wish and through the liberality of all the faithful, will be a lasting memorial of this
happy event, so We desire to offer this Encyclical Letter in testimony of Our gratitude. It tells of those living stones which rest upon the living cornerstone, which is Christ, and are built together into a holy
temple, far surpassing any temple built by hands, into a habitation of God in the Spirit. 
8. But the chief reason for Our present exposition of this sublime doctrine is Our solicitude for the souls entrusted to
Us. Much indeed has been written on this subject; and We know that many today are turning with greater zest to a study which delights and nourishes Christian piety. This, it would seem, is chiefly because a revived
interest in the sacred liturgy, the more widely spread custom of frequent Communion, and the more fervent devotion to the Sacred Heart of Jesus practiced today, have brought many souls to a deeper consideration of the
unsearchable riches of Christ which are preserved in the Church. Moreover, recent pronouncements on Catholic Action, by drawing closer the bonds of union between Christians and between them and the ecclesiastical
hierarchy and especially the Roman Pontiff, have undoubtedly helped not a little to place this truth in its proper light. Nevertheless, while We can derive legitimate joy from these considerations, We must confess that
grave errors with regard to this doctrine are being spread among those outside the true Church, and that among the faithful, also, inaccurate or thoroughly false ideas are being disseminated which turn minds aside from
the straight path of truth.
9. For while there still survives a false rationalism, which ridicules anything that transcends and defies the power of human genius, and which is accompanied by a cognate
error, the so-called popular naturalism, which sees and wills to see in the Church nothing but a juridical and social union, there is on the other hand a false mysticism
creeping in, which, in its attempt to eliminate the immovable frontier that separates creatures from their Creator, falsifies the Sacred Scriptures.
10. As a result of these conflicting and mutually antagonistic
schools of thought, some through vain fear, look upon so profound a doctrine as something dangerous, and so they shrink from it as from the beautiful but forbidden fruit of paradise. But this is not so. Mysteries
revealed by God cannot be harmful to men, nor should they remain as treasures hidden in a field, useless. They have been given from on high precisely to help the spiritual progress of those who study them in a spirit of
piety. For, as the Vatican Council teaches, "reason illumined by faith, if it seeks earnestly, piously and wisely, does attain under God, to a certain and most helpful knowledge of mysteries, by considering their
analogy with what it knows naturally, and their mutual relations, and their common relations with man's last end," although, as the same holy Synod observes, reason, even thus illumined, "is never capable of
understanding those mysteries as it does those truths which forms its proper object." 
11. After pondering all this long and seriously before God We consider it part of Our pastoral duty to explain to the
entire flock of Christ through this Encyclical Letter the doctrine of the Mystical Body of Christ and of the union in this Body of the faithful with the divine Redeemer; and then, from this consoling doctrine, to draw
certain lessons that will make a deeper study of this mystery bear yet richer fruits of perfection and holiness. Our purpose is to throw an added ray of glory on the supreme beauty of the Church; to bring out into
fuller light the exalted supernatural nobility of the faithful who in the Body of Christ are united with their Head; and finally, to exclude definitely the many current errors with regard to this matter.
12. When one
reflects on the origin of this doctrine, there come to mind at once the words of the Apostle: "Where sin abounded, grace did more abound." All know that the father of the whole human race was constituted by
God in so exalted a state that he was to hand on to his posterity, together with earthly existence, the heavenly life of divine grace. But after the unhappy fall of Adam, the whole human race, infected by the hereditary
stain, lost their participation in the divine nature, and we were all "children of wrath." But the all-merciful God "so loved the world as to give His only-begotten Son," and the Word of the
Eternal Father with the same divine love assumed human nature from the race of Adam - but as an innocent and spotless nature - so that He, as the new Adam, might be the source whence the grace of the Holy Spirit should
flow unto all the children of the first parent. Through the sin of the first man they had been excluded from adoption as children of God; through the Word incarnate, made brothers according to the flesh of the
only-begotten Son of God, they receive also the power to become the sons of God. As He hung upon the Cross, Christ Jesus not only appeased the justice of the Eternal Father which had been violated, but He also won
for us, His brethren, an ineffable flow of graces. It was possible for Him of Himself to impart these graces to mankind directly; but He willed to do so only through a visible Church made up of men, so that through her
all might cooperate with Him in dispensing the graces of Redemption. As the Word of God willed to make use of our nature, when in excruciating agony He would redeem mankind, so in the same way throughout the centuries
He makes use of the Church that the work begun might endure. 
13. If we would define and describe this true Church of Jesus Christ - which is the One, Holy, Catholic, Apostolic and Roman Church  - we shall
find nothing more noble, more sublime, or more divine than the expression "the Mystical Body of Christ" - an expression which springs from and is, as it were, the fair flowering of the repeated teaching of the
Sacred Scriptures and the Holy Fathers.
14. That the Church is a body is frequently asserted in the Sacred Scriptures. "Christ," says the Apostle, "is the Head of the Body of the
Church." If the Church is a body, it must be an unbroken unity, according to those words of Paul: "Though many we are one body in Christ." But it is not enough that the Body of the Church should
be an unbroken unity; it must also be something definite and perceptible to the senses as Our predecessor of happy memory, Leo XIII, in his Encyclical Satis Cognitum
asserts: "the Church is visible because she is a body. Hence they err in a matter of divine truth, who imagine the Church to be invisible, intangible, a something merely "pneumatological" as they say, by which many Christian communities, though they differ from each other in their profession of faith, are untied by an invisible bond.
15. But a body calls also for a multiplicity of members, which are linked together in such a way as to help one another. And as in the body when one member suffers, all the other members share its pain, and the
healthy members come to the assistance of the ailing, so in the Church the individual members do not live for themselves alone, but also help their fellows, and all work in mutual collaboration for the common comfort
and for the more perfect building up of the whole Body.
16. Again, as in nature a body is not formed by any haphazard grouping of members but must be constituted of organs, that is of members, that have not the same
function and are arranged in due order; so for this reason above all the Church is called a body, that it is constituted by the coalescence of structurally untied parts, and that it has a variety of members reciprocally
dependent. It is thus the Apostle describes the Church when he writes: "As in one body we have many members, but all the members have not the same office: so we being many are one body in Christ, and everyone
members one of another." 
17. One must not think, however, that this ordered or "organic" structure of the body of the Church contains only hierarchical elements and with them is complete; or, as an
opposite opinion holds, that it is composed only of those who enjoy charismatic gifts - though members gifted with miraculous powers will never be lacking in the Church. That those who exercise sacred power in this Body
are its chief members must be maintained uncompromisingly. It is through them, by commission of the Divine Redeemer Himself, that Christ's apostolate as Teacher, King and Priest is to endure. At the same time, when the
Fathers of the Church sing the praises of this Mystical Body of Christ, with its ministries, its variety of ranks, its officers, it conditions, its orders, its duties, they are thinking not only of those who have
received Holy Orders, but of all those too, who, following the evangelical counsels, pass their lives either actively among men, or hidden in the silence of the cloister, or who aim at combining the active and
contemplative life according to their Institute; as also of those who, though living in the world, consecrate themselves wholeheartedly to spiritual or corporal works of mercy, and of those in the state of holy
matrimony. Indeed, let this be clearly understood, especially in our days, fathers and mothers of families, those who are godparents through Baptism, and in particular those members of the laity who collaborate with the
ecclesiastical hierarchy in spreading the Kingdom of the Divine Redeemer occupy an honorable, if often a lowly, place in the Christian community, and even they under the impulse of God and with His help, can reach the
heights of supreme holiness, which, Jesus Christ has promised, will never be wanting to the Church.
18. Now we see that the human body is given the proper means to provide for its own life, health and growth, and for
that of all its members. Similarly, the Savior of mankind out of His infinite goodness has provided in a wonderful way for His Mystical Body, endowing it with the Sacraments, so that, as though by an uninterrupted
series of graces, its members should be sustained from birth to death, and that generous provision might be made for the social needs of the Church. Through the waters of Baptism those who are born into this world dead
in sin are not only born again and made members of the Church, but being stamped with a spiritual seal they become able and fit to receive the other Sacraments. By the chrism of Confirmation, the faithful are given
added strength to protect and defend the Church, their Mother, and the faith she has given them. In the Sacrament of Penance a saving medicine is offered for the members of the Church who have fallen into sin, not only
to provide for their own health, but to remove from other members of the Mystical Body all danger of contagion, or rather to afford them an incentive to virtue, and the example of a virtuous act.
19. Nor is that all;
for in the Holy Eucharist the faithful are nourished and strengthened at the same banquet and by a divine, ineffable bond are united with each other and with the Divine Head of the whole Body. Finally, like a devoted
mother, the Church is at the bedside of those who are sick unto death; and if it be not always God's will that by the holy anointing she restore health to the mortal body, nevertheless she administers spiritual medicine
to the wounded soul and sends new citizens to heaven - to be her new advocates - who will enjoy forever the happiness of God.
20. For the social needs of the Church Christ has provided in a particular way by the
institution of two other Sacraments. Through Matrimony, in which the contracting parties are ministers of grace to each other, provision is made for the external and duly regulated increase of Christian society, and,
what is of greater importance, for the correct religious education of the children, without which this Mystical Body would be in grave danger. Through Holy Orders men are set aside and consecrated to God, to offer the
Sacrifice of the Eucharistic Victim, to nourish the flock of the faithful with the Bread of Angels and the food of doctrine, to guide them in the way of God's commandments and counsels and to strengthen them with all
other supernatural helps.
21. In this connection it must be borne in mind that, as God at the beginning of time endowed man's body with most ample power to subject all creatures to himself, and to increase and
multiply and fill the earth, so at the beginning of the Christian era, He supplied the Church with the means necessary to overcome the countless dangers and to fill not only the whole world but the realms of heaven as
22. Actually only those are to be included as members of the Church who have been baptized and profess the true faith, and who have not been so unfortunate as to separate themselves from the unity of the Body,
or been excluded by legitimate authority for grave faults committed. "For in one spirit" says the Apostle, "were we all baptized into one Body, whether Jews or Gentiles, whether bond or free." As
therefore in the true Christian community there is only one Body, one Spirit, one Lord, and one Baptism, so there can be only one faith. And therefore, if a man refuse to hear the Church, let him be considered - so
the Lord commands - as a heathen and a publican.  It follows that those who are divided in faith or government cannot be living in the unity of such a Body, nor can they be living the life of its one Divine Spirit.
23. Nor must one imagine that the Body of the Church, just because it bears the name of Christ, is made up during the days of its earthly pilgrimage only of members conspicuous for their holiness, or that it consists
only of those whom God has predestined to eternal happiness. It is owing to the Savior's infinite mercy that place is allowed in His Mystical Body here below for those whom, of old, He did not exclude from the
banquet. For not every sin, however grave it may be, is such as of its own nature to sever a man from the Body of the Church, as does schism or heresy or apostasy. Men may lose charity and divine grace through sin,
thus becoming incapable of supernatural merit, and yet not be deprived of all life if they hold fast to faith and Christian hope, and if, illumined from above, they are spurred on by the interior promptings of the Holy
Spirit to salutary fear and are moved to prayer and penance for their sins.
24. Let every one then abhor sin, which defiles the mystical members of our Redeemer; but if anyone unhappily falls and his obstinacy has not
made him unworthy of communion with the faithful, let him be received with great love, and let eager charity see in him a weak member of Jesus Christ. For, as the Bishop of Hippo remarks, it is better "to be cured
within the Church's community than to be cut off from its body as incurable members." "As long as a member still forms part of the body there is no reason to despair of its cure; once it has been cut off,
it can be neither cured nor healed." 
25. In the course of the present study, Venerable Brethren, we have thus far seen that the Church is so constituted that it may be likened to a body. We must now explain
clearly and precisely why it is to be called not merely a body, but the Body of Jesus Christ. This follows from the fact that our Lord is the Founder, the Head, the Support and the Savior of this Mystical Body.
We set out briefly to expound in what sense Christ founded His social Body, the following thought of Our predecessor of happy memory, Leo XIII, occurs to Us at once: "The Church which, already conceived, came forth
from the side of the second Adam in His sleep on the Cross, first showed Herself before the eyes of men on the great day of Pentecost." For the Divine Redeemer began the building of the mystical temple of the
Church when by His preaching He made known His Precepts; He completed it when he hung glorified on the Cross; and He manifested and proclaimed it when He sent the Holy Ghost as Paraclete in visible form on His disciples.
27. For while fulfilling His office as preacher He chose Apostles, sending them as He had been sent by the Father  - namely, as teachers, rulers, instruments of holiness in the assembly of the believers; He
appointed their Chief and His Vicar on earth; He made known to them all things and whatsoever He had heard from His Father;  He also determined that through Baptism  those who should believe would be
incorporated in the Body of the Church; and finally, when He came to the close of His life, He instituted at the Last Supper the wonderful Sacrifice and Sacrament of the Eucharist.
28. That He completed His work on
the gibbet of the Cross is the unanimous teaching of the holy Fathers who assert that the Church was born from the side of our Savior on the Cross like a new Eve, mother of all the living.  "And it is
now," says the great St. Ambrose, speaking of the pierced side of Christ, "that it is built, it is now that it is formed, it is now that it is...molded, it is now that it is created... Now it is that arises a
spiritual house, a holy priesthood."  One who reverently examines this venerable teaching will easily discover the reasons on which it is based.
29. And first of all, by the death of our Redeemer, the New
Testament took the place of the Old Law which had been abolished; then the Law of Christ together with its mysteries, enactments, institutions, and sacred rites was ratified for the whole world in the blood of Jesus
Christ. For, while our Divine Savior was preaching in a restricted area - He was not sent but to the sheep that were lost of the House of Israel  - the Law and the Gospel were together in force;  but on the
gibbet of His death Jesus made void the Law with its decrees  fastened the handwriting of the Old Testament to the Cross,  establishing the New Testament in His blood shed for the whole human race. "To
such an extent, then," says St. Leo the Great, speaking of the Cross of our Lord, "was there effected a transfer from the Law to the Gospel, from the Synagogue to the Church, from the many sacrifices to one
Victim, that, as Our Lord expired, that mystical veil which shut off the innermost part of the temple and its sacred secret was rent violently from top to bottom." 
30. On the Cross then the Old Law died,
soon to be buried and to be a bearer of death,  in order to give way to the New Testament of which Christ had chosen the Apostles as qualified ministers;  and although He had been constituted the Head of the
whole human family in the womb of the Blessed Virgin, it is by the power of the Cross that our Savior exercises fully the office itself of Head of His Church. "For it was through His triumph on the Cross,"
according to the teaching of the Angelic and Common Doctor, "that He won power and dominion over the gentiles"; by that same victory He increased the immense treasure of graces, which, as He reigns in
glory in heaven, He lavishes continually on His mortal members; it was by His blood shed on the Cross that God's anger was averted and that all the heavenly gifts, especially the spiritual graces of the New and Eternal
Testament, could then flow from the fountains of our Savior for the salvation of men, of the faithful above all; it was on the tree of the Cross, finally, that He entered into possession of His Church, that is, of all
the members of His Mystical Body; for they would not have been untied to this Mystical Body through the waters of Baptism except by the salutary virtue of the Cross, by which they had been already brought under the
complete sway of Christ.