Lumen Gentium, the Dogmatic Constitution on the Church, is one of the principal documents of the Second Vatican Council. This dogmatic constitution was promulgated by Pope Paul VI on November 21, 1964, following approval by the assembled bishops by a vote of 2,151 to 5. As is customary with significant Roman Catholic Church documents, it is known by its first words, "Lumen Gentium", Latin for "Light of the Nations".
The numbers given correspond to section numbers within the text.
In its first chapter, titled "The Mystery of the Church," is the famous statement that "the sole Church of Christ which in the Creed we profess to be one, holy, catholic and apostolic, which our Saviour, after His Resurrection, commissioned Peter to shepherd, and him and the other apostles to extend and direct with authority, which He erected for all ages as 'the pillar and mainstay of the truth.' This Church, constituted and organized as a society in the present world, subsists in the Catholic Church, which is governed by the successor of Peter and by the bishops in communion with him" (Lumen gentium, 8). The document immediately adds: "Nevertheless, many elements of sanctification and of truth are found outside its visible confines." Paragraph 14 explains: "Whosoever, therefore, knowing that the Catholic Church was made necessary by Christ, would refuse to enter or to remain in it, could not be saved."
One of the key portions of Lumen Gentium is its second chapter, with its declaration that the Church is "the People of God":
At all times and in every race God has given welcome to who so ever fears Him and does what is right. God, however, does not make men holy and save them merely as individuals, without bond or link between one another. Rather has it pleased Him to bring men together as one people, a people which acknowledges Him in truth and serves Him in holiness…
Christ instituted this new covenant, the new testament, that is to say, in His Blood, calling together a people made up of Jew and gentile, making them one, not according to the flesh but in the Spirit. This was to be the new People of God. For those who believe in Christ, who are reborn not from a perishable but from an imperishable seed through the word of the living God, not from the flesh but from water and the Holy Spirit, are finally established as "a chosen race, a royal priesthood, a holy nation, a purchased people . . . who in times past were not a people, but are now the people of God". (Lumen gentium, 9)
In the second chapter, the Council teaches that God wills to save people not just as individuals but as a people. For this reason God chose the Israelite people to be his own people and established a covenant with it, as a preparation and figure of the covenant ratified in Christ that constitutes the new People of God, which would be one, not according to the flesh, but in the Spirit and which is called the Church of Christ (Lumen gentium, 9).
All human beings are called to belong to the Church. Not all are fully incorporated into the Church, but "the Church knows that she is joined in many ways to the baptized who are honored by the name of Christ, but who do not however profess the Catholic faith in its entirety or have not preserved unity or communion under the successor of Peter" (Lumen gentium, 15). In addition, the Church declares the possibility of Salvation for non-Christians and even non-deists:
"Finally, those who have not yet received the Gospel are related in various ways to the people of God. In the first place we must recall the people to whom the testament and the promises were given and from whom Christ was born according to the flesh. On account of their fathers this people remains most dear to God, for God does not repent of the gifts He makes nor of the calls He issues.(126); But the plan of salvation also includes those who acknowledge the Creator. In the first place amongst these there are the Mohamedans, who, professing to hold the faith of Abraham, along with us adore the one and merciful God, who on the last day will judge mankind. Nor is God far distant from those who in shadows and images seek the unknown God, for it is He who gives to all men life and breath and all things,and as Saviour wills that all men be saved.Those also can attain to salvation who through no fault of their own do not know the Gospel of Christ or His Church, yet sincerely seek God and moved by grace strive by their deeds to do His will as it is known to them through the dictates of conscience.Nor does Divine Providence deny the helps necessary for salvation to those who, without blame on their part, have not yet arrived at an explicit knowledge of God and with His grace strive to live a good life." (Lumen gentium 16)
The third chapter of the document, which spoke of the bishops as a "college" that, within the Church, succeeds to the place of the "college" or "stable group" of the apostles and is "the subject of supreme and full power over the universal Church, provided we understand this body together with its head, the Roman Pontiff".
Conservative bishops in the Council were fearful that the idea of the College of Bishops would be interpreted as a new conciliarism, a fifteenth-century idea that an ecumenical council was the supreme authority under Christ in the Catholic Church. Of the members of the Council, 322, a minority, but a substantial minority, voted against any mention whatever in the document of a "college" of bishops), and were now proposing 47 amendments to chapter III. Accordingly, a "Preliminary Note of Explanation" (in Latin, Nota explicativa praevia", often referred to as "the Nota praevia") intended to reconcile them with the text was added on 16 November 1964. The Note reaffirmed that the college of bishops exercises its authority only with the assent of the pope, thus safeguarding the primacy and pastoral independence of the pope.
The Note achieved its purpose: on the following day, 17 November, the No votes against chapter III dropped to 46, a number that may have included some who opposed it because they felt the Preliminary Note of Explanation had weakened the concept of collegiality. In the final vote on 18 November only 5 of the over 2200 participants voted against the dogmatic constitution as a whole.
The Note is introduced by the following words: "A preliminary note of explanation is being given to the Council Fathers from higher authority, regarding the Modi bearing on Chapter III of the Schema de Ecclesia; the doctrine set forth in Chapter III ought to be explained and understood in accordance with the meaning and intent of this explanatory note." "Higher authority" refers to the Pope, Paul VI, and "the Schema de Ecclesia" to the draft text for the dogmatic constitution Lumen gentium. By "the Modi" is meant the proposals for amendments of that draft text which some of the Council participants had presented.
The Note was thus added by papal authority, consistently with the idea that the consent of the Pope, as head of the College of Bishops was necessary, and that he had the "right to make his consent dependent on an interpretation determined in advance".
The Preliminary Note of Explanation did not in fact alter the value of the statement on collegiality in the text of Lumen Gentium: it "strengthened the adherence to the doctrine of the First Vatican Council on the primacy, but it did not subsequently strike out anything from the direct divine origin of the episcopal office and its function, and the responsibility of the College of Bishops for the Universal Church."
Part 4 of the Note reads:
|“||As Supreme Pastor of the Church, the Supreme Pontiff can always exercise his power at will, as his very office demands. Though it is always in existence, the College is not as a result permanently engaged in strictly collegial activity; the Church's Tradition makes this clear. In other words, the College is not always fully active [in actu pleno]; rather, it acts as a college in the strict sense only from time to time and only with the consent of its head. The phrase 'with the consent of its head' is used to avoid the idea of dependence on some kind of outsider; the term "consent" suggests rather communion between the head and the members, and implies the need for an act which belongs properly to the competence of the head. This is explicitly affirmed in n. 22, 12  and is explained at the end of that section. The word "only" takes in all cases. It is evident from this that the norms approved by the supreme authority must always be observed. Cf. Modus 84 It is clear throughout that it is a question of the bishops acting in conjunction with their head, never of the bishops acting independently of the Pope. In the latter instance, without the action of the head, the bishops are not able to act as a College: this is clear from the concept of "College." This hierarchical communion of all the bishops with the Supreme Pontiff is certainly firmly established in Tradition.||”|
Though they differ from one another in essence and not only in degree, the common priesthood of the faithful and the ministerial or hierarchical priesthood are nonetheless interrelated: each of them in its own special way is a participation in the one priesthood of Christ. The ministerial priest, by the sacred power he enjoys, teaches and rules the priestly people; acting in the person of Christ, he makes present the eucharistic sacrifice, and offers it to God in the name of all the people. But the faithful, in virtue of their royal priesthood, join in the offering of the Eucharist. They likewise exercise that priesthood in receiving the sacraments, in prayer and thanksgiving, in the witness of a holy life, and by self-denial and active charity. (Lumen gentium 10)
This theme was built on in the fifth chapter, "The Universal Call to Holiness":
Thus it is evident to everyone, that all the faithful of Christ of whatever rank or status, are called to the fullness of the Christian life and to the perfection of charity; by this holiness as such a more human manner of living is promoted in this earthly society. In order that the faithful may reach this perfection, they must use their strength accordingly as they have received it, as a gift from Christ. They must follow in His footsteps and conform themselves to His image seeking the will of the Father in all things. They must devote themselves with all their being to the glory of God and the service of their neighbor. In this way, the holiness of the People of God will grow into an abundant harvest of good, as is admirably shown by the life of so many saints in Church history.
The classes and duties of life are many, but holiness is one-that sanctity which is cultivated by all who are moved by the Spirit of God, and who obey the voice of the Father and worship God the Father in spirit and in truth. These people follow the poor Christ, the humble and cross-bearing Christ in order to be worthy of being sharers in His glory. Every person must walk unhesitatingly according to his own personal gifts and duties in the path of living faith, which arouses hope and works through charity. (Lumen gentium 40, 41)
The chapter on Mary was the subject of debate. Original plans had called for a separate document about the role of Mary, keeping the document on the Church "ecumenical," in the sense of "non-offensive" to Protestant Christians, who viewed special veneration of Mary with suspicion. However, the Council Fathers insisted, with the support of the Pope, that, as Mary's place is within the Church, treatment of her should appear within the Constitution on the Church.
Vatican Council II was sensitive to the views of other Christians, as the council, at the request of Pope John XXIII, hoped to promote Christian unity, but knew there are different concepts about Mary among other Christians, especially Protestants. The council spoke of Mary as "Mediatrix," as strengthening — not lessening — confidence in Christ as the one essential Mediator. The council, in speaking of Mary, used a biblical approach, with strong emphasis on her pilgrimage of faith. They also drew heavily from the Fathers of the Church, which Christians of all denominations respect.
Pope Paul VI, in a speech to the council fathers, spoke as follows: "This year, the homage of our Council appears much more precious and significant. By the promulgation of today's constitution, which has as its crown and summit a whole chapter dedicated to our Lady, we can rightly affirm that the present session ends as an incomparable hymn of praise in honor of Mary." "It is the first time, in fact, and saying it fills our souls with profound emotion, that an Ecumenical Council has presented such a vast synthesis of the Catholic doctrine regarding the place which the Blessed Mary occupies in the mystery of Christ and of the Church."
Some bishops had advocated a dogma of Mary Mediatrix, Advocate and Co-Redemptrix. However, the Constitution did not mention the controversial notion of Marian co-redemption and instead only included a specific section on the Blessed Virgin Mary. In part, this was due to the rise of Ecumenism and the need to maintain positive relations with Protestants.
The council did not consider Mary as separate from its treatment of the Church, but discussed the mystery of Mary in the larger mystery of Christ and his Church.
Certain Traditionalist Catholic groups, particularly Sedevacantists, consider Lumen Gentium to be the demarcation of when the Roman Church fell into heresy, pointing to the use of "subsistit in" rather than "est" as an abdication of the Church's historic (and to them compulsory) identification of itself alone as God's church.
In an interview with Frankfurter Allgemeine Zeitung, then-Cardinal Ratzinger (now Pope Benedict XVI) responded to this criticism as follows:
The concept expressed by 'is' (to be) is far broader than that expressed by 'to subsist'. 'To subsist' is a very precise way of being, that is, to be as a subject, which exists in itself. Thus the Council Fathers meant to say that the being of the Church as such is a broader entity than the Roman Catholic Church, but within the latter it acquires, in an incomparable way, the character of a true and proper subject.