Paul VI, Mysterium fidei (On the Holy Eucharist)

Encyclical Letter of His Holiness Pope Paul VI

Given at Rome, at St. Peter's, the third day of September, the Feast of Pope St. Pius X, in the year 1965, the third year of our pontificate.

Venerable brothers, in this very matter which we are discussing, there are not lacking reasons for serious pastoral concern and anxiety. The awareness of our apostolic duty does not allow us to be silent in the face of these problems. Indeed, we are aware of the fact that, among those who deal with this Most Holy Mystery in written or spoken word, there are some who with reference either to Masses which are celebrated in private, or to the dogma of transubstantiation, or to devotion to the Eucharist, spread abroad opinions which disturb the faithful and fill their minds with no little confusion about matters of faith. It is as if everyone were permitted to consign to oblivion doctrine already defined by the Church, or else to interpret it in such a way as to weaken the genuine meaning of the words or the recognized force of the concepts involved.

To confirm what we have said by examples, it is not allowable to emphasize what is called the "communal" Mass to the disparagement of Masses celebrated in private, or to exaggerate the element of sacramental sign as if the symbolism, which all certainly admit in the Eucharist, expresses fully and exhausts completely the mode of Christ's presence in this sacrament. Nor is it allowable to discuss the mystery of transubstantiation without mentioning what the Council of Trent stated about the marvelous conversion of the whole substance of the bread into the Body and of the whole substance of the wine into the Blood of Christ, speaking rather only of what is called "transignification" and "transfiguration," or finally to propose and act upon the opinion according to which, in the Consecrated Hosts which remain after the celebration of the sacrifice of the Mass, Christ Our Lord is no longer present.

Everyone can see that the spread of these and similar opinions does great harm to the faith and devotion to the Divine Eucharist.

And therefore, so that the hope aroused by the council, that a flourishing of eucharistic piety which is now pervading the whole Church, be not frustrated by this spread of false opinions, we have with apostolic authority decided to address you, venerable brothers, and to express our mind on this subject.