UNIONI PROFESSIONALI : V. ORDINI E COLLEGI PROFESSIONALI.
UNITY OF THE CHURCH. – The Church is one, that is, undivided in itself and distinct from every other society. Therefore, unity is an essential property of the Church and one of its distinguishing marks. The unity of the Church may be considered from within, that is, as it appears to the consciousness of itself (a rather dogmatic point of view); and from without, as it manifests itself to those who are outside it (a rather apologetic point of view).
I. THE UNITY AS AN ESSENTIAL PROPERTY
1. Notion of the unity of the Church
The unity of the Church is determined by its nature as a supernatural society founded by the Son of God. Just as the human race forms a unity of all the descendants of the first Adam and of Eve, the “mother of all living” (Gen. 3, 20), so the Church, the society or community of the regenerate, forms a unity of all the descendants of the second Adam, Christ, children of the second Eve, Mary, who is both representative and type of the Church (Io. 19, 25-27; Apoc. 12). The Church is therefore one in Christ, as also in his priesthood and sacrifice, which is Christ’s. It is one in its Sacraments, especially in Baptism, by which man is incorporated into the unity of the Church and separated from the rest of humanity. Then it is one in the Sacrament of Orders, through which there is unity with the past, the apostolic succession, and which is an indispensable condition for the Sacrament of Sacraments, the Eucharist, which unites with Christ and with all those who are in Christ; hence it is called par excellence “the Sacrament of unity.”The Church, one in all its ontological reality, is also one in its truth, its teaching office, and its faith. Furthermore, the Church is one in its organic hierarchical government. The unity of teaching and government is essentially concentrated in the one visible head of the Church, the Roman Pontiff, Vicar of the one invisible head, Christ, and the sole successor of Peter, from whom the primacy of apostolic succession derives. The characteristic unity of the Catholic hierarchy, of bishops and priests, and of the Catholic laity consists in union with the successor of s. Peter.
Other related notions fall within the sphere of unity. The uniqueness of the Church is its unity insofar as it excludes any other similar one. Then the unity of the Church may be considered in the succession of time, insofar as the Church of today is identical with that of yesterday and tomorrow (v. CHIESA); it may be considered in the grouping of many classes into a whole, in its diffusion through space according to its geographical extension among the different peoples and nations (v. CHIESA); and it may be considered in its spiritual depth, that is, as union with God through the Grace of Christ (v. SANTITÀ DELLA CHIESA). In short, the unity of the Church as such concerns all the bonds by which it is joined as a body to its head, Jesus Christ; this is the truth recalled by s. Paul in Col. 2, 19, exhorting the faithful to hold fast to “the head, from whom the whole body, being fitted and joined together by means of its ligaments and joints, grows with an increase that comes from God.” The proximate efficient cause of the unity of the Church is the will of Christ, who intended to found one Church; its ultimate cause is the will and good pleasure of the triune God, Father, Son, and Holy Spirit, source and ultimate foundation, in his one divine essence and in his free will, of every existing organic unity; its final cause is indicated by s. Paul when he affirms that all things will be subject to the Son, as the Son will be subject to the Father, “so that God may be all in all things” (I Cor. 15, 28).
2. The sources of Revelation concerning the unity of the Church
a) Sacred Scripture. — In the Old Testament the Church is prefigured as one in the ark of Noah, the only one saved from the universal Flood; in the one chosen people, saved from Egyptian captivity and led through the desert into the promised land; the Church is spoken of when Isaiah announces that “in the last days the mountain of the house of the Lord shall be established upon the top of all mountains” (Is. 2, 2). In the Song of Songs the bride is spoken of as a figure of the Church: “One is my dove, my perfect one; she is the only one of her mother, the chosen one of her who bore her” (Cant. 6, 8). In the New Testament, Jesus speaks twice of the Church, and uses the article (Mt. 16, 18 and 18, 17). He expressly says that he wished to build “his Church” upon Peter—the rock, hence one and distinct from any other that might claim to be founded by the “Son of the living God” (Mt. 16, 16). S. John reports Jesus’ discourse in which he calls himself “the good shepherd” and foretells that there “will be one flock and one shepherd” (Io. 10, 11; 14; 16), a flock that the risen Jesus entrusts, with all “his lambs” and all “his sheep,” to the care of Peter (Io. 21, 15 sgg).S. Paul speaks either of the Church in the singular, meaning the one and universal Church, or of Churches in the plural, in the sense of particular or local Churches belonging to the same Church (e.g.: Rom. 16, 16: “all the Churches of Christ greet you”); therefore, when he speaks in the singular, the Apostle indicates the Church as one: “Christ is the head of the Church” (Eph. 5, 23), which is, according to the same apostle, “the body” of Christ, “and he is the savior of his body” (ibid. V. 23); he immediately adds: “Men, love your wives, as Christ also loved the Church, and gave himself for her...” (ibid. V. 25); “for no one ever hated his own flesh: but nourishes and cherishes it, as Christ also does the Church: because we are members of his body, of his flesh, and of his bones” (ibid. vv. 29-30). S. Paul compares the Church to a “bride of Christ”; thereby he demonstrates its unity and uniqueness. Since the bride is in herself a physical person, she is joined to the bridegroom, another physical person, first of all by moral bonds; but, furthermore, “the two shall be one flesh” (Mt. 19, 5; Gen. 2, 24; Eph. 5, 31). The body, on the other hand, distinguished by the head, forms together with it a unity that is more than moral, namely, organic and physical. From the interweaving of these two images it follows that the unity of the Church is more than purely moral (cf. encyc. Mystici Corporis: AAS, 35 [1943], p. 222).
According to s. Paul himself, the conscious moral union of Christians must correspond to the ontological union of the Church; hence he exhorts the Ephesians to be “careful to preserve the unity of the spirit in the bond of peace. One body and one spirit, as you have also been called to one hope through your vocation. One Lord, one faith, one Baptism. One God and Father of all, who is above all, and through all things, and in us all” (Eph. 4, 3-6; cf. 1, 22-23). In the text cited, other exegetes understand “spirit” as referring to the Holy Spirit. The unity of the Church therefore comprises the body and spirit of the faithful, consists in faith and Baptism, and, as is even more clearly evident from I Cor. 12, 12-13, in the bond with the Holy Spirit, with Christ, and with God the Father: “As the body is one, and has many members, and all the members of the body, though many, are nevertheless one body: so also is Christ. For in one Spirit we were all baptized to be one body, whether Jews or Gentiles, whether servants or free: and we have all been given to drink of one Spirit.” And as in Baptism, so in the Eucharist the unity of the Church is manifested: “One bread, one body are we many, all who partake of that one bread” (I Cor. 10, 17).
b) Definitions and documents of the Church. — As in the Apostolic Creed, so in all the creeds the profession of faith is made “in the Church”—not in Churches—“in one Church,” “in the one Church.” In the Constantinopolitan Creed: “in one, holy, catholic, and apostolic Church” (Denz-U, 86). In the profession prescribed for the Waldensians (1208, under Innocent III): “We confess ...”
one Church, not of heretics, but the holy Roman, catholic, and apostolic Church” (Denz-U., 423). Famous is the bull “Unam sanctam” of 1302 by Boniface VIII, in which Cant. 6:8, Ps. 21:21—“Erue... de manu canis unicam meam”—and John 19:23, the “seamless tunic,” are applied to the Church: “thus of the one and only Church there is one body, one head, not two heads like a monster, namely Christ and the vicar of Christ, Peter, and the successor of Peter” (Denz-U., 468). Three further documents should be recalled: the letter of the Holy Office on the u. of the C. (unicity) of 1864 (Denz-U., 1686), the Satis cognitum (v.) of 1896 on the u. of the C., an invitation that all should return to the u. (Denz-U., 1954 add.), and the encyclical of Pius XII Mystici Corporis Christi, quod est Ecclesia of 1943 (AAS, 35 [1943], p. 193 add.).
c) Christian Antiquity. — The testimony of Christian antiquity and of the holy Fathers is very clear regarding the u. of the C. Already in the Didachè, in connection with the Eucharist, the one bread, gathered from many grains, is seen as a symbol of the unification of human beings in the Church (9, 4; 10, 5). S. Ignatius not only insists on the particular u. of the C., united under a single bishop with his clergy in the Eucharistic bread (e.g., Philad., 4; Eph. 20, 2), but also speaks of the “one body of the Church” of Christ in general (e.g., Smirn., 1, 2). In the Shepherd of Hermas, “the tower” is the Church (Vis., 3, 5, 1; Sim., 9, 17, 4). For s. Irenaeus the Church “dwells in one house,” has one soul and the same heart, “proclaims the faith and hands it down,” possessing only “one mouth” (Adv. haeres., 1, 10, 2). For Clement of Alexandria, just as the Father, the Word, and the Holy Spirit are one, so “one alone becomes the virgin mother: I am pleased to call her Church” (Paedag., 1, 6, 42, 1). And he is of the opinion that “the true Church is one ... the one which the heresies strive to cut into many” (Strom., VII, 17). According to Tertullian, all the Churches descend from the first Church of the Apostles; they are “first and apostolic” if all together they prove their “unity” in peace and fraternity (De praescr. haer., 20, 4).
The testimony of s. Cyprian is exceedingly clear, both in his letters and in De catholicae Ecclesiae unitate. He writes: “God is one and Christ (is) one, and one (is) the Church and one the chair founded upon Peter by the voice of the Lord. No new priesthood can be established or arise outside the one altar and the one priesthood. Whoever gathers elsewhere dissipates” (Ep., 43, 5). Or again: “The Church is one, and it cannot be one (that is, the same) within and without. If, then, it is with Novatian, it was not with Cornelius (the Pope)” (Ep., 69, 3). In De catholicum. Eccl. unitate, chap. 5: “The episcopate is one, of which each (bishop) holds a part in solidum. The Church is one...; the Church, pervaded by the light of the Lord, extends its rays throughout the whole world: yet the light is one, which is diffused everywhere, and the unity of the body is not divided.” In the text s. Cyprian cites Cant. 6:8 and Eph. 4:4 and compares the Church to a fruitful mother, the Church as bride of Christ, and sees her prefigured in Noah’s ark (ibid. 6; cf. however PRIMATO DI S. PIETRO E DEL ROMANO PONTEFIORE).
Among the great Eastern Fathers and doctors of the fourth and fifth centuries, numerous testimonies can be gathered concerning the u. of the C. in the faith and communion of the universal Church. The Roman Primacy as a principle of u. is expressed there more in practice (doctrinal and disciplinary appeals to the supreme authority) than in doctrine. On the unity of the Body of Christ, s. Athanasius, s. Basil, s. Cyril of Jerusalem (in explaining the Symbol), s. Gregory of Nazianzus, and s. Epiphanius are very explicit; s. John Chrysostom particularly emphasizes the unity of communion and charity; s. Cyril of Alexandria, too, is very explicit on this point. The Western doctors of the same period likewise highlight the unity of the Body of Christ: s. Hilary, s. Ambrose, and s. Jerome. One of the clearest in this regard is s. Optatus of Milevis, according to whom Peter, head of all the Apostles and therefore called Cephas, was bishop of Rome, “in whose chair unity is preserved by all, in opposition to schisms” (Contra Parmenianum Donatistam, II, 2).
Richest of all, however, is the doctrine of s. Augustine, who
illustrates the u. of the C. with various images drawn from Holy Scripture and, in the struggle against the Donatists and Pelagians, insists on the doctrinal and disciplinary primacy of Rome as the center of unity; this doctrine was later clearly expressed by s. Leo the Great, who explained his succession by affirming that Peter was chosen “so that, although in the people of God there are many priests and many shepherds, Peter alone should properly govern them all” (Serm., IV, 2).
d) Theologians. — In the Middle Ages, the theology of the u. of the C. gradually became more refined. In s. Thomas one finds the broad outlines of the doctrine on the unity of the Body of Christ (Sum. Theol., 3, q. 8). Noteworthy is De regimine christiano (1301–1302) Giacomo da Viterbo (v.), which treats of u. in a special chapter (1, 3), seeing in the union of the multitude of the faithful rather “union” than “unity.” The first complete exposition on a theological-canonical TORQUEMADA, JUAN DE (v.) in his Summa de Ecclesia, in which he vindicates u. against the Western and Eastern schismatics.
In modern times, the great speculative theologians Caetano, De Lugo, and Suárez (Disp. IX de fide) expound the principles of the u. of the C. The apologists oppose to the false marks advanced by the Protestants the true marks, foremost among them u. as Catholic doctrine understands II. With polemical intent, the subject is developed by Suárez in his Defensio fidei adversus Anglos, by s. Robert Bellarmine, by Cardinal Du Perron (against the theory of King James of England that the Church, in its u., was like a confederation of religious societies agreeing on a minimum of beliefs), and by the Jansenist P. Nicole in his treatise De l'unité de l'Eglise ou Réputation du nouveau système de M. Jurieu (Paris 1687). In more recent times, the notion of the u. of the C. was reexamined especially under the influence of the revival of patristic studies. The celebrated book by J. A. Möhler (v.), Die Einheit in der Kirche oder das Prinzip des Katholizismus, dargestellt im Geist der Kirchenväter der drei ersten Jahrhunderte (1825), should be recalled; it very probably inspired the modern ecclesiologist of the dissident Russians, A. S. Chomjakov, in his brief treatise La Chiesa è una (ca. 1845). Before and after the Vatican Council, down to the present day, many treatises De Ecclesia have appeared that deal extensively with u. But the impetus toward more profound investigations of the u. of the C. came from the so-called “ecumenical movement” (v. ECUMENISMO) among Christians now divided into innumerable denominations.
II. THE U. AS A DISTINCTIVE NOTE. —
3. Disunity
Schism (v.) cf. I Cor. 1:10 (agg.), heresy (v.), and secularization—that is, gradual separation from the entire work of the Church—are opposed to the u.4. False concepts of the u
Over the centuries, such concepts arose either from the desire to justify one’s own schismatic or heretical position, or from the attempt by Catholics to combat separations or to clarify the traditional concept of the u. St. Cyprian, for example, in his refutation of the Novatian schism, clarified many essential features of ecclesiastical u.; yet he did not always express with sufficient clarity and precision that unity of government in the Church finds its full realization in the perpetuity of the Primacy of Peter. Thus, in modern times, Möhler, in explaining its true u. to Protestants, emphasized too exclusively the internal principle of u., namely the Holy Spirit, who actualizes mystical unity, while neglecting its external and visible aspect; he thus arrived at a conception similar to that of St. Cyprian, which he nevertheless corrected and completed in his later work, the Simbolica (1832).conciliarism (v.), which placed the unity and authority of universal councils above the Pope, was due in Western Schism (v.). Analogous is the conciliarism of the dissident Easterners, according to which the individual national autocephalous Churches, independent of one another in government, form a confederation of coordinated communities connected only by certain bonds of charity, generally weak, and occasionally by an exchange of ideas. This is a highly imperfect form of u., which not infrequently becomes disunity and even schism (for example, the present hierarchy of the Patriarchal Church of Moscow is in a state of schism vis-à-vis the hierarchy of Metropolitan Anastasius, formerly resident at Karlovtsi in Yugoslavia and now in New York; the Church of Moscow is also engaged in open conflict with the «Ecumenical Patriarch» of Constantinople).
The Easterners have therefore begun to conceive the u. d. C., especially since Chomjakov (v.), in a vague and Protestantizing sense, as «sobornost'» (that is, etymologically, «conciliarity», though historically identical with «catholicity»), meaning «unity in freedom and love», while relegating the visible u. of the Church to a secondary position; a conception already very close to the Protestant one, which sees the u. d. C. predominantly in the invisible elements of the Body of Christ.
While the dissident Easterners still exclude Catholics and Protestants from the u. of the true Church—that is, their own Church—because, according to Chomjakov, Catholics have exaggerated the principle of u. and Protestants that of freedom, ecumenism instead is based on the so-called «branch» theory, according to which the Christian confessions are branches of the same tree. This theory was condemned by Pius IX in 1864, insofar as it teaches that universal u. d. C. should result from the three Christian communities together: the Roman Catholic, the Greek-Selamatic, and the Anglican. Vladimir Soloviev, too, at times expressed himself as though universal u. d. C. resulted only from the future union of dissident Catholics, Byzantine Slavs, and Protestants; hence his axiom, «ceterum censeo instaurandam esse Ecclesiae unitatem», is true only in the sense that u. must be restored through the return of the separated to u.
3. Apologetic Value of the u. — The u. is not merely an essential property of the Church; for all who are outside it, it is also a sign of recognition, a means by which they may find the true and only Church. It is: a) the most comprehensive note; the other three (or more) notes may be regarded as particular cases of u. (v. above); b) true and complete u. results only from the totality of all the bonds that essentially exist in the Church (cf. Col. 2:19), namely, the bonds of faith, sacrifice, and the Sacraments, and of a single and united government.
III. REALIZATION OF CHRISTIAN UNITY
In addition to the efforts and acts of union on the part of the Catholic Church, especially of the Papacy, defined by the Russian Čadacev (1794–1856) as the “visible sign of unity and, since separation has existed, also a sign of reunion,” there have also been attempts at union on the part of the dissenters, with their successors down to the present ecumenism, full of genuine impulses, yet essentially fruitless, insofar as they seek to dispense with the foundation of unity, that is, the rock placed by Christ himself as the foundation of his Church.No one can deny that there is greater unity in the Catholic Church than in the dissident Eastern communities, and greater unity among these than among the Protestants of the various denominations. Unable to deny the fact of the greater unity in the Catholic Church, the dissenters sometimes seek to invalidate its spontaneous and natural apologetic value by asserting that Catholic unity is rather the effect of external coercion than the fruit of intimate conviction.
To bring the separated back to unity requires a twofold kind of centripetal force: a) objective forces, instituted by Christ himself, namely, internal Grace and the visible rock of Peter; b) subjective forces, namely, freedom of cooperation and the exercise of the unitive Christian virtues, especially humility and fraternal charity, on both sides, in opposition to the centrifugal forces of pride and particularism, granting everyone in the common house of God freedom wherever the obligatory unity of dogma is not at issue, that is, freedom in rites and in ancient and venerable local customs and traditions. The “pre-eminently” centripetal and unitive force was taught by Jesus in the priestly prayer: «That they may all be one, as you, Father, are in me and I in you, that they also may be one in us» (Io. 17,21).
BBL.: the most complete study is that of A. Michel, Unité de l'Eglise, in DThC, XV, cols. 2172–2230; cf. also G. Thils, Les notes de l'Eglise dans l'apolog. depuis la Réforme, Gembloux 1937 (v. T. Zapelena, De via notarum in recenti quodam opere, in Gregorianum 19 [1938], pp. 88–109, 445–68); M. J. Congar, Chrétiens déunis. Principes d'un «occuménisme catholique» (collection Unam Sanctum, no. 1), Paris 1937; L'Eglise est une. Hommage à Möhler, edited by P. Chaillet, Paris 1939; E. Morsch, Le Corps Mystique du Christ, 2 vols., 2nd ed., Brussels 1936; id., La théol. du Corps Mystique, 2 vols., Paris–Brussels 1944; L. Cerfaux, La Théologie de l'Eglise suivant 1st Paul (Collection Unam Sanctam, 10), 2nd ed., Paris 1948; N. Flew, The Nature of the Church. Papers presented to the Theological Commission appointed by the Continuation Committee of the World Conference on Faith and Order, London 1952, Bernardo Schultze.