Constant Teaching of the Popes and the Councils

52. But this is no time for assembling a long list of evidence. Instead, We would rather recall the firmness of faith and complete unanimity that the Church displayed in opposing Berengarius who gave in to certain difficulties raised by human reasoning and first dared to deny the Eucharistic conversion. More than once she threatened to condemn him unless he retracted. Thus it was that Our predecessor, St. Gregory VII, commanded him to swear to the following oath: "I believe in my heart and openly profess that the bread and wine that are placed on the altar are, through the mystery of the sacred prayer and the words of the Redeemer, substantially changed into the true and proper and lifegiving flesh and blood of Jesus Christ our Lord, and that after the consecration they are the true body of Christ—which was born of the Virgin and which hung on the Cross as an offering for the salvation of the world—and the true blood of Christ—which flowed from His side—and not just as a sign and by reason of the power of the sacrament, but in the very truth and reality of their substance and in what is proper to their nature." ⁵⁶

53. We have a wonderful example of the stability of the Catholic faith in the way in which these words meet with such complete agreement in the constant teaching of the Ecumenical Councils of the Lateran, Constance, Florence and Trent on the mystery of the Eucharistic conversion, whether it be contained in their explanations of the teaching of the Church or in their condemnations of error.

54. After the Council of Trent, Our predecessor, Pius VI, issued a serious warning, on the occasion of the errors of the Synod of Pistoia, that parish priests not neglect to speak of transubstantiation, which is listed among the articles of the faith, in the course of carrying out their office of teaching. ⁵⁷ Similarly, Our Predecessor of happy memory, Pius XII, recalled the bounds beyond which those who were carrying on subtle discussion of the mystery of transubstantiation might not pass; ⁵⁸ and We Ourself, at the National Eucharistic Congress that was recently celebrated at Pisa, bore open and solemn witness to the faith of the Church, in fulfillment of Our apostolic duty. ⁵⁹

55. Moreover, the Catholic Church has held firm to this belief in the presence of Christ's Body and Blood in the Eucharist not only in her teaching but in her life as well, since she has at all times paid this great Sacrament the worship known as "latria," which may be given to God alone. As St. Augustine says: "It was in His flesh that Christ walked among us and it is His flesh that He has given us to eat for our salvation; but no one eats of this flesh without having first adored it . . . and not only do we not sin in thus adoring it, but we would be sinning if we did not do so." ⁶⁰