Part One

   To Our Venerable Brethren the Patriarchs, Primates, Archbishops, Bishops, and other Ordinaries in Peace and Communion with the Apostolic See.

   Venerable Brethren, Health and Benediction.

1. It is sufficiently well known unto you that no small share of Our thoughts and of Our care is devoted to Our endeavour to bring back to the fold, placed under the guardianship of Jesus Christ, the Chief Pastor of souls, sheep that have strayed. Bent upon this, We have thought it most conducive to this salutary end and purpose to describe the exemplar and, as it were, the lineaments of the Church. Amongst these the most worthy of Our chief consideration is Unity. This the Divine Author impressed on it as a lasting sign of truth and of unconquerable strength. The essential beauty and comeliness of the Church ought greatly to influence the minds of those who consider it. Nor is it improbable that ignorance may be dispelled by the consideration; that false ideas and prejudices may be dissipated from the minds chiefly of those who find themselves in error without fault of theirs; and that even a love for the Church may be stirred up in the souls of men, like unto that charity wherewith Christ loved and united himself to that spouse redeemed by His precious blood. "Christ loved the Church, and delivered Himself up for it" (Eph. v., 25).

   If those about to come back to their most loving Mother (not yet fully known, or culpably abandoned) should perceive that their return involves, not indeed the shedding of their blood (at which price nevertheless the Church was bought by Jesus Christ), but some lesser trouble and labour, let them clearly understand that this burden has been laid on them not by the will of man but by the will and command of God. They may thus, by the help of heavenly grace, realize and feel the truth of the divine saying, "My yoke is sweet and my burden light" (Matt. xi., 30).

   Wherefore, having put all Our hope in the "Father of lights," from whom "cometh every best gift and every perfect gift" (Ep. James i., 17) - from Him, namely, who alone "gives the increase" (I Cor. iii., 6) - We earnestly pray that He will graciously grant Us the power of bringing conviction home to the minds of men.

2. Although God can do by His own power all that is effected by created natures, nevertheless in the counsels of His loving Providence He has preferred to help men by the instrumentality of men. And, as in the natural order He does not usually give full perfection except by means of man's work and action, so also He makes use of human aid for that which lies beyond the limits of nature, that is to say, for the sanctification and salvation of souls. But it is obvious that nothing can be communicated amongst men save by means of external things which the senses can perceive. For this reason the Son of God assumed human nature - "who being in the form of God.... emptied himself, taking the form of a servant, being made in the likeness of man" (Philipp. ii., 6,7) - and thus living on earth He taught his doctrine and gave His laws, conversing with men.

3. And, since it was necessary that His divine mission should be perpetuated to the end of time, He took to Himself Disciples, trained by himself, and made them partakers of His own authority. And, when He had invoked upon them from Heaven the Spirit of Truth, He bade them go through the whole world and faithfully preach to all nations, what He had taught and what He had commanded, so that by the profession of His doctrine, and the observance of His laws, the human race might attain to holiness on earth and neverending happiness in Heaven. In this wise, and on this principle, the Church was begotten. If we consider the chief end of His Church and the proximate efficient causes of salvation, it is undoubtedly spiritual; but in regard to those who constitute it, and to the things which lead to these spiritual gifts, it is external and necessarily visible. The Apostles received a mission to teach by visible and audible signs, and they discharged their mission only by words and acts which certainly appealed to the senses. So that their voices falling upon the ears of those who heard them begot faith in souls - "Faith cometh by hearing, and hearing by the words of Christ" (Rom. x., 17). And faith itself - that is assent given to the first and supreme truth - though residing essentially in the intellect, must be manifested by outward profession - "For with the heart we believe unto justice, but with the mouth confession is made unto salvation" (Rom. x., 10). In the same way in man, nothing is more internal than heavenly grace which begets sanctity, but the ordinary and chief means of obtaining grace are external: that is to say, the sacraments which are administered by men specially chosen for that purpose, by means of certain ordinances.

   Jesus Christ commanded His Apostles and their successors to the end of time to teach and rule the nations. He ordered the nations to accept their teaching and obey their authority. But his correlation of rights and duties in the Christian commonwealth not only could not have been made permanent, but could not even have been initiated except through the senses, which are of all things the messengers and interpreters.

   For this reason the Church is so often called in Holy Writ a body, and even the body of Christ - "Now you are the body of Christ" (I Cor. xii., 27) - and precisely because it is a body is the Church visible: and because it is the body of Christ is it living and energizing, because by the infusion of His power Christ guards and sustains it, just as the vine gives nourishment and renders fruitful the branches united to it. And as in animals the vital principle is unseen and invisible, and is evidenced and manifested by the movements and action of the members, so the principle of supernatural life in the Church is clearly shown in that which is done by it.

   From this it follows that those who arbitrarily conjure up and picture to themselves a hidden and invisible Church are in grievous and pernicious error: as also are those who regard the Church as a human institution which claims a certain obedience in discipline and external duties, but which is without the perennial communication of the gifts of divine grace, and without all that which testifies by constant and undoubted signs to the existence of that life which is drawn from God. It is assuredly as impossible that the Church of Jesus Christ can be the one or the other, as that man should be a body alone or a soul alone. The connection and union of both elements is as absolutely necessary to the true Church as the intimate union of the soul and body is to human nature. The Church is not something dead: it is the body of Christ endowed with supernatural life. As Christ, the Head and Exemplar, is not wholly in His visible human nature, which Photinians and Nestorians assert, nor wholly in the invisible divine nature, as the Monophysites hold, but is one, from and in both natures, visible and invisible; so the mystical body of Christ is the true Church, only because its visible parts draw life and power from the supernatural gifts and other things whence spring their very nature and essence. But since the Church is such by divine will and constitution, such it must uniformly remain to the end of time. If it did not, then it would not have been founded as perpetual, and the end set before it would have been limited to some certain place and to some certain period of time; both of which are contrary to the truth. The union consequently of visible and invisible elements because it harmonizes with the natural order and by God's will belongs to the very essence of the Church, must necessarily remain so long as the Church itself shall endure. Wherefore Chrysostom writes: "Secede not from the Church: for nothing is stronger than the Church. Thy hope is the Church; thy salvation is the Church; thy refuge is the Church. It is higher than the heavens and wider than the earth. It never grows old, but is ever full of vigour. Wherefore Holy Writ pointing to its strength and stability calls it a mountain" (Hom. De capto Eutropio, n. 6).

   Also Augustine says: "Unbelievers think that the Christian religion will last for a certain period in the world and will then disappear. But it will remain as long as the sun - as long as the sun rises and sets: that is, as long as the ages of time shall roll, the Church of God - the true body of Christ on earth - will not disappear" (In Psalm. lxx., n. 8). And in another place: "The Church will totter if its foundation shakes; but how can Christ be moved?...Christ remaining immovable, it (the Church, shall never be shaken. Where are they that say that the Church has disappeared from the world, when it cannot even be shaken?" (Enarratio in Psalm. ciii., sermo ii., n. 5).

   He who seeks the truth must be guided by these fundamental principles. That is to say, that Christ the Lord instituted and formed the Church: wherefore when we are asked what its nature is, the main thing is to see what Christ wished and what in fact He did. Judged by such a criterion it is the unity of the Church which must be principally considered; and of this, for the general good, it has seemed useful to speak in this Encyclical.

4. It is so evident from the clear and frequent testimonies of Holy Writ that the true Church of Jesus Christ is one, that no Christian can dare to deny it. But in judging and determining the nature of this unity many have erred in various ways. Not the foundation of the Church alone, but its whole constitution, belongs to the class of things effected by Christ's free choice. For this reason the entire case must be judged by what was actually done. We must consequently investigate not how the Church may possibly be one, but how He, who founded it, willed that it should be one. But when we consider what was actually done we find that Jesus Christ did not, in point of fact, institute a Church to embrace several communities similar in nature, but in themselves distinct, and lacking those bonds which render the Church unique and indivisible after that manner in which in the symbol of our faith we profess: "I believe in one Church." "The Church in respect of its unity belongs to the category of things indivisible by nature, though heretics try to divide it into many parts...We say, therefore, that the Catholic Church is unique in its essence, in its doctrine, in its origin, and in its excellence...Furthermore, the eminence of the Church arises from its unity, as the principle of its constitution - a unity surpassing all else, and having nothing like unto it or equal to it" (S. Clemens Alexandrinus, Stronmatum lib. viii., c. 17). For this reason Christ, speaking of the mystical edifice, mentions only one Church, which he calls His own - "I will build my church; " any other Church except this one, since it has not been founded by Christ, cannot be the true Church. This becomes even more evident when the purpose of the Divine Founder is considered. For what did Christ, the Lord, ask? What did He wish in regard to the Church founded, or about to be founded? This: to transmit to it the same mission and the same mandate which He had received from the Father, that they should be perpetuated. This He clearly resolved to do: this He actually did. "As the Father hath sent me, I also send you" (John xx., 21). "Ad thou hast sent Me into the world I also have sent them into the world" (John xvii., 18).

   But the mission of Christ is to save that which had perished: that is to say, not some nations or peoples, but the whole human race, without distinction of time or place. "The Son of Man came that the world might be saved by Him" (John iii., 17). "For there is no other name under Heaven given to men whereby we must be saved" (Acts iv., 12). The Church, therefore, is bound to communicate without stint to all men, and to transmit through all ages, the salvation effected by Jesus Christ, and the blessings flowing there from. Wherefore, by the will of its Founder, it is necessary that this Church should be one in all lands and at all times. to justify the existence of more than one Church it would be necessary to go outside this world, and to create a new and unheard - of race of men.

   That the one Church should embrace all men everywhere and at all times was seen and foretold by Isaias, when looking into the future he saw the appearance of a mountain conspicuous by its all surpassing altitude, which set forth the image of "The House of the Lord" - that is, of the Church, "And in the last days the mountain of the House of the Lord shall be prepared on the top of the mountains" (Isa. ii., 2).

   But this mountain which towers over all other mountains is one; and the House of the Lord to which all nations shall come to seek the rule of living is also one. "And all nations shall flow into it. And many people shall go, and say: Come, and let us go up to the mountain of the Lord, and to the House of the God of Jacob, and He will teach us His ways, and we will walk in His paths" (Ibid., ii., 2-3).

   Explaining this passage, Optatus of Milevis says: "It is written in the prophet Isaias: 'from Sion the law shall go forth and the word of the Lord from Jerusalem.' For it is not on Mount Sion that Isaias sees the valley, but on the holy mountain, that is, the Church, which has raised itself conspicuously throughout the entire Roman world under the whole heavens....The Church is, therefore, the spiritual Sion in which Christ has been constituted King by God the Father, and which exists throughout the entire earth, on which there is but one Catholic Church" (De Schism. Donatist., lib. iii., n. 2). And Augustine says: "What can be so manifest as a mountain, or so well known? There are, it is true, mountains which are unknown because they are situated in some remote part of the earth But this mountain is not unknown; for it has filled the whole face of the world, and about this it is said that it is prepared on the summit of the mountains" (In Ep. Joan., tract i., n. 13).

5. Furthermore, the Son of God decreed that the Church should be His mystical body, with which He should be united as the Head, after the manner of the human body which He assumed, to which the natural head is physiologically united. As He took to Himself a mortal body, which He gave to suffering and death in order to pay the price of man's redemption, so also He has one mystical body in which and through which He renders men partakers of holiness and of eternal salvation. God "hath made Him (Christ) head over all the Church, which is His body" (Eph. i., 22-23). Scattered and separated members cannot possibly cohere with the head so as to make one body. But St. Paul says: "All members of the body, whereas they are many, yet are one body, so also is Christ" (I Cor. xii., 12). Wherefore this mystical body, he declares, is "compacted and fitly jointed together. The head, Christ: from whom the whole body, being compacted and fitly jointed together, by what every joint supplieth according to the operation in the measure of every part" (Eph. iv., 15-16). And so dispersed members, separated one from the other, cannot be united with one and the same head. "There is one God, and one Christ; and His Church is one and the faith is one; and one the people, joined together in the solid unity of the body in the bond of concord. This unity cannot be broken, nor the one body divided by the separation of its constituent parts" (S. Cyprianus, De Cath. Eccl. Unitateccl. Unitate, n. 23). And to set forth more clearly the unity of the Church, he makes use of the illustration of a living body, the members of which cannot possibly live unless united to the head and drawing from it their vital force. Separated from the head they must of necessity die. "The Church," he says, "cannot be divided into parts by the separation and cutting asunder of its members. What is cut away from the mother cannot live or breathe apart" (Ibid.). What similarity is there between a dead and a living body? "For no man ever hated his own flesh, but nourisheth and cherisheth it, as also Christ doth the Church: because we are members of His body, of His flesh, and of His bones" (Eph. v., 29-30).

   Another head like to Christ must be invented - that is, another Christ if besides the one Church, which is His body, men wish to set up another. "See what you must beware of - see what you must avoid - see what you must dread. It happens that, as in the human body, some member may be cut off a hand, a finger, a foot. Does the soul follow the amputated member? As long as it was in the body, it lived; separated, it forfeits its life. So the Christian is a Catholic as long as he lives in the body: cut off from it he becomes a heretic - the life of the spirit follows not the amputated member" (S. Augustinus, Sermo cclxvii., n. 4).

   The Church of Christ, therefore, is one and the same for ever; those who leave it depart from the will and command of Christ, the Lord - leaving the path of salvation they enter on that of perdition. "Whosoever is separated from the Church is united to an adulteress. He has cut himself off from the promises of the Church, and he who leaves the Church of Christ cannot arrive at the rewards of Christ....He who observes not this unity observes not the law of God, holds not the faith of the Father and the Son, clings not to life and salvation" (S. Cyprianus, De Cath. Eccl. Unitate, n. 6).

6. But He, indeed, Who made this one Church, also gave it unity, that is, He made it such that all who are to belong to it must be united by the closest bonds, so as to form one society, one kingdom, one body - "one body and one spirit as you are called in one hope of your calling (Eph. iv., 4). Jesus Christ, when His death was nigh at hand, declared His will in this matter, and solemnly offered it up, thus addressing His Father: "Not for them only do I pray, but for them also who through their word shall believe in Me...that they also may be one in Us...that they may be made perfect in one" John xvii., 20-21 23). Yea, He commanded that this unity should be so closely knit and so perfect amongst His followers that it might, in some measure, shadow forth the union between Himself and His Father: "I pray that they all may be one as Thou Father in Me and I in Thee" (Ibid. 21).

   Agreement and union of minds is the necessary foundation of this perfect concord amongst men, from which concurrence of wills and similarity of action are the natural results. Wherefore, in His divine wisdom, He ordained in His Church Unity of Faith; a virtue which is the first of those bonds which unite man to God, and whence we receive the name of the faithful - "one Lord, one faith, one baptism" (Eph. iv., 5). That is, as there is one Lord and one baptism, so should all Christians, without exception, have but one faith. And so the Apostle St. Paul not merely begs, but entreats and implores Christians to be all of the same mind, and to avoid difference of opinions: "I beseech you, brethren, by the name of our Lord Jesus Christ, that you all speak the same thing, and that there be no schisms amongst you, and that you be perfect in the same mind and in the same judgment" (I Cor. i., 10). Such passages certainly need no interpreter; they speak clearly enough for themselves. Besides, all who profess Christianity allow that there can be but one faith. It is of the greatest importance and indeed of absolute necessity, as to which many are deceived, that the nature and character of this unity should be recognized. And, as We have already stated, this is not to be ascertained by conjecture, but by the certain knowledge of what was done; that is by seeking for and ascertaining what kind of unity in faith has been commanded by Jesus Christ.

7. The heavenly doctrine of Christ, although for the most part committed to writing by divine inspiration, could not unite the minds of men if left to the human intellect alone. It would, for this very reason, be subject to various and contradictory interpretations. This is so, not only because of the nature of the doctrine itself and of the mysteries it involves, but also because of the divergencies of the human mind and of the disturbing element of conflicting passions. From a variety of interpretations a variety of beliefs is necessarily begotten; hence come controversies, dissensions and wranglings such as have arisen in the past, even in the first ages of the Church. Irenaeus writes of heretics as follows: "Admitting the sacred Scriptures they distort the interpretations" (Lib. iii., cap. 12, n. 12). And Augustine: "Heresies have arisen, and certain perverse views ensnaring souls and precipitating them into the abyss only when the Scriptures, good in themselves, are not properly understood" (In Evang. Joan., tract xviii., cap. 5, n. 1). Besides Holy Writ it was absolutely necessary to insure this union of men's minds - to effect and preserve unity of ideas - that there should be another principle. This the wisdom of God requires: for He could not have willed that the faith should be one if He did not provide means sufficient for the preservation of this unity; and this Holy Writ clearly sets forth as We shall presently point out. Assuredly the infinite power of God is not bound by anything, all things obey it as so many passive instruments. In regard to this external principle, therefore, we must inquire which one of all the means in His power Christ did actually adopt. For this purpose it is necessary to recall in thought the institution of Christianity.

Continued in Part Two of Satis Cognitum

POPE LEO XIII's SATIS COGNITUM www.DailyCatholic.org