What the Catholic Church has to say about transubstantiation:
“And because that Christ, our Redeemer, declared that which He offered under the species of bread to be truly His own body, therefore has it ever been a firm belief in the Church of God, and this holy Synod doth now declare it anew, that, by the consecration of the bread and of the wine, a conversion is made of the whole substance of the bread into the substance of the body of Christ our Lord, and of the whole substance of the wine into the substance of His blood;
which conversion is, by the holy Catholic Church, suitably and properly called Transubstantiation.” (1561 - Council of Trent,
Session XIII, c. IV)
“The doctrine of the synod [of Pistoia] … absolutely omits to make any mention of
transubstantiation, or conversion of the whole substance of the bread into the body, and of the whole substance of the wine into the blood, which the Council of Trent defined as an article of faith, and which is contained in the solemn profession of faith; … by an indiscreet and suspicious omission of this sort knowledge is taken away both of an article pertaining to faith, and also of
the word consecrated by the Church to protect the profession of it…” (1794 - Pope Pius VI,
Auctorem Fidei 29, addressing the errors of a false council held in Pistoia) [It should be pointed out that the synod of Pistoia *did say that “after the consecration Christ is truly, really, substantially under the species [and that] the whole substance of the bread and wine ceases, appearances only remaining”, but Pius VI considered the complete omission of the term “transubstantiation” to be “dangerous, derogatory to the exposition of Catholic truth about
the dogma of transubstantiation, [and] favorable to heretics”!]
“Some even say that
the doctrine of transubstantiation transubstantiationis doctrinam], based on an antiquated philosophic notion of substance, should be so modified that the real presence of Christ in the Holy Eucharist be reduced to a kind of symbolism, whereby the consecrated species would be merely efficacious signs of the spiritual presence of Christ and of His intimate union with the faithful members of His Mystical Body.” (1950 - Pope Pius XII,
Humani Generis 26)
“For We can see that some of those who are dealing with this Most Holy Mystery in speech and writing are disseminating opinions on Masses celebrated in private or on
the dogma of transubstantiation dogma transsubstantiationis] that are disturbing the minds of the faithful and causing them no small measure of confusion about matters of faith, just as if it were all right for someone to take doctrine that has already been defined by the Church and consign it to oblivion or else interpret it in such a way as to weaken the genuine meaning of the words or the recognized force of the concepts involved.” (1965 - Pope Paul VI,
Mysterium Fidei 10)
“To give an example of what We are talking about, it is not permissible …
to discuss the mystery of transubstantiation without mentioning what the Council of Trent had to say about the marvelous conversion of the whole substance of the bread into the Body and the whole substance of the wine into the Blood of Christ, as if they involve nothing more than ‘transignification,’ or ‘transfinalization’ as they call it.” (1965 - Pope Paul VI,
Mysterium Fidei 11)
“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.” (1965 - Pope Paul VI,
Mysterium Fidei 54)
“[Jesus Christ] is substantially present there through the conversion of the bread and wine that, following the Council of Trent, is
most accurately termed transubstantiation.” (1967 -
Eucharisticum Mysterium 3f)
“Moreover, the wondrous mystery of the Lord’s real presence under the eucharistic species, reaffirmed by the Second Vatican Council6 and other documents of the Church’s Magisterium in the same sense and with the same words that the Council of Trent had proposed as a matter of faith, is proclaimed in the celebration of Mass not only by means of the very words of consecration, by which
Christ becomes present through transubstantiation…” (2002 - GIRM 2)
