Subsistit in

Phrase in Lumen gentium

Subsistit in ("subsists in") is a Latin phrase which appears in Lumen gentium, the document on the church from the Second Vatican Council of the Catholic Church. Since the council, the reason for use of the term "subsists in" rather than simply "is" has been disputed. Generally, those who see little or no change in church teaching in Vatican II insist on the equivalence of subsistit in and "is". Those who point to a new, ecumenical thrust in Vatican II insist that the term was introduced as a compromise after much discussion, and acknowledges new elements in the council's teaching. The context of the statement is (emphasis added):

The correct meaning of "subsists in" has important implications for how the Catholic Church views itself and its relations with other Christian communities and other religions. Questions have been raised about whether Lumen gentium altered the longstanding phrase according to which the Church of Christ is (Latin est) the Catholic Church. Mystici corporis Christi states: "this true Church of Jesus Christ" and "the Mystical Body of Christ" is "the One, Holy, Catholic, Apostolic and Roman Church". This position was later reaffirmed in Humani generis. Lumen gentium does recognize that other Christian ecclesial communities have elements of sanctification and of truth. And the Council used the traditional term "Church"— in the sense of "particular Church" and not "universal Church"— to refer to the Eastern Churches not in full communion with the Catholic Church. "These Churches", it says, "although separated from us, yet possess true sacraments and above all, by apostolic succession, the priesthood and the Eucharist, whereby they are linked with us in closest intimacy". The Catholic Church used both the "subsists in" and "is" formula in the Second Vatican Council, stating in the Decree on the Eastern Churches: "The Holy Catholic Church, which is the Mystical Body of Christ, is made up of the faithful who are organically united in the Holy Spirit by the same faith, the same sacraments and the same government".

Both before and after the 16th century Protestant Reformation, Catholic theology identified the Church of Christ with the Catholic Church. This continued through the teaching of popes Pius XI and Pius XII. At the Second Vatican Council, the preparatory draft for the Decree on the Church contained this long held teaching, following Pius XII in identifying the Mystical Body of Christ with the Catholic Church. Cardinal Walter Kasper has pointed out that, concerning the claim that the fullness of the Church of Christ resides in the Catholic Church, that this "does not refer to subjective holiness but to the sacramental and institutional means of salvation, the sacraments and the ministries." But Francis A. Sullivan pointed out:

Cardinal Dulles argues subsitit in to be "an expression deliberately chosen to allow for the ecclesial reality of other Christian communities", implying that non Catholic Christians are members of the Body of Christ, and thus of the Church.

Catholic priest Hervé Legrand [fr] states that the part concerning subsistit in within the 1985 notification concerning Leonard Boff's books, as well as within Dominus Iesus, are wrong. He states that "recourse to the Acta Synodalia [of Vatican II] makes it possible to establish, with almost absolute certainty, that the recourse to the verb 'to subsist' was done in order to avoid the exclusive identification between the Church of Christ and the Catholic Church", and that "the decision taken in commission offers no trace of a scholastic meaning given to the term subsistit, but it offers evidence of the use of this word to avoid the pure and simple identification between the Church of Christ and our [Catholic] Church".

The Society of Saint Pius X consider Lumen gentium one of several demarcations of when the post Vatican II Church has issued problematic statements, pointing to the use of "subsistit in" rather than "est" as an abdication of the Catholic Church's (to the SSPX compulsory) identification of itself alone as God's church.