The Mystery of Change in the Eucharist

Author: Roberto Masi


Roberto Masi

"We believe that, as the bread and wine consecrated by Our Lord at the Last Supper were changed into his body and blood soon afterwards to be offered for us on the Cross, in the same way the bread and wine consecrated by the priest are changed into the body and blood of Christ gloriously reigning in heaven".                                                             Credo of the People of God

The change brought about in the Eucharist is taught by Christ himself in both his action and his words at the Last Supper. It is recorded by the Synoptics (Mk. 14, 22-24; Mth. 26, 26-27; Lk. 22, 19-20) and by St. Paul (I Cor. 11, 23b-25) that Jesus took bread and giving it to his disciples said: "This is my body". Then he took a chalice of wine and offering it exclaimed: "This is my blood".

Jesus meant to say that what he held in his hand, the bread and the wine, was his body and his blood. He is the Word incarnate, the Redeemer; he is man but he is also God. Therefore in his positive statements he cannot err, but always expresses the exact truth. Given that his statement does not correspond to the reality, then the reality itself is changed to correspond identically with what Christ has said. Therefore, since Christ took into his hands the common bread and wine which were on the table, in order that his words be true we must conclude that these words changed the objective reality, that is to say changed the bread into the body of Christ and the wine into his blood, whilst what was apparent to the senses remained unchanged, as the immediate experience of those present bore witness.

Thus the words of Christ effect a mysterious but true and real change. On the altar are the body and blood of Christ; the bread and wine no longer exist but have been totally changed into the body and blood of the Saviour by means of a true though mysterious conversion.

As St. Thomas observes (S. Th. III q. 75, a. 2), a thing can be where it was not before either because it is transported there or else when something else is changed into it. In the Holy Eucharist Our Lord's body cannot be transported from paradise by local motion, as is evident; therefore it is not possible to think of the presence of Christ's body under the consecrated species except by the conversion of the bread into that body.

Again, the Council of Trent lays down that "just as Christ... declared to be truly his body that which was offered under the species of bread, so the Church has always believed that by the consecration of the bread and wine there comes about the conversion of the whole substance of the bread into the substance of the body of Christ... and of the whole substance of the wine into the substance of his blood" Thus the Pope's thought echoes that of St. Thomas and the Council of Trent, but expresses it in contemporary language insofar as he avoids the word "substance", unacceptable to many today, while maintaining the fulness of the tridentine teaching.

In the conversion that takes place in the Eucharist the appearances remain, that is the physico-chemical properties of the bread and wine perceptible by the senses, called the "species" in the patristic tradition.


This mysterious conversion is indicated by the Council of Trent in the particular name given to it—"transubstantiation", insofar as in it the sensible appearances remain and only the ontological reality of the bread and wine changes, that reality which scholastic theology, following along aristotelian lines, called substance. According to this latter terminology, in the eucharistic conversion the substance of the bread is changed into the substance of the body of Christ—"substantia transit in substantiam"; hence the word transubstantiation repeated by Paul VI. Here consequently, the word "substance" is not to be understood in its technical philosophical sense but in its common, popular meaning, as the reality which makes bread bread, as distinct from and opposed to what is immediately apparent to the senses.

"Transubstantiation" is a wondrous and unique conversion, as the Council of Trent has it (Sess. XIII, can. 2; Ds. 1652); that is to say, it is a true conversion insofar as the bread truly becomes Our Lord's body and the wine his blood. But it is something wondrousand unique, that is to say, mysterious and to that extent not comprehensible by our intelligence, in the sense that an existing reality (bread and wine) becomes another reality already complete in itself and in its own existence (the body and blood of Christ), which in no way changes because of that conversion: it neither increases nor alters but remains as it was before. One individual thing becomes identical with another; this one becomes that one, as St. Thomas puts it (Cont. Gent. L IV, c. 63).

The bread and wine are not annihilated, reduced to nothing, but are truly changed into the body and blood of Christ, that is to say, into Christ who remains as before without actual change; Christ does not increase corporally by reason of the conversion brought about in the Mass, nor does he grow less by the consuming of the Eucharist in Holy Communion.

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This most ancient doctrine of the Church, divine in origin, is presented again by Paul VI in his Act of Faith. Therefore this is what all the faithful of Christ must believe.

Those who, as is well known, in order to render the eucharistic mystery more comprehensible to the men of today, attempt a different presentation of the same for pastoral ecumenical purposes, changing the terminology or even making use of modern mental classifications drawn from present-day philosophy or other sciences, must maintain the revealed truth. That is to say, they must truly and sincerely believe that after the consecration the reality of the bread and wine ceases to be, whilst "in objective reality and independently of our mind", under the sacramental species are, in a mysterious way, the body and blood of Christ "truly, really, substantially".

Because there is, on the part of the man of today, a lack of understanding of the thought and terminology of medieval scholasticism, various theologians have attempted to re-interpret the eucharistic dogma taught by Christ, transmitted by Fathers and scholastics, and defined by the Councils, particularly by Trent, using the categories of signification and finalization. Whence they have declared that in Holy Mass the bread and wine no longer signify ordinary food but the love of Christ totally given to man in food and to the Father in sacrifice. Consequently in the consecration there occurs a change of meaning and of purpose, that is (as they say) a transignification and a transfinalization.


In his Encyclical Mysterium Fidei, Pope Paul points out that, with transubstantiation, the species certainly acquire a new signification and purpose, precisely because they no longer indicate ordinary food but the body and blood of Christ, the spiritual nourishment of the soul (A.S.S. 57, 1965, p. 766).

The German episcopate also point out, in para 45 of a collective pastoral letter containing the best of the eucharistic theology which has appeared since Mysterium Fidei,that the concept of " transubstantiation" can be elaborated and perfected in such a way as to present this mystery under other aspects. The two modern theories of "transignification" and "transfinalization" have precisely such a scope and in that sense can be accepted.

The terms are indeed new, say the German bishops, but their content is old: the one emphasizes the fact that the natural bread becomes spiritual bread, the other that this new food is food for eternal life. The basis of the whole doctrine is that the bread and wine are truly changed into the body and blood of Christ.

Therefore, the German bishops conclude, the doctrine of transubstantiation can be elaborated in terms of transignification and transfinalization, but not replaced by these. That is to say that the new doctrines are acceptable only insofar as they presuppose the tridentine dogma, even though the latter is now expressed and elaborated in a more modern fashion. In that sense they represent a true progress in eucharistic theology to the extent that they bring out aspects which were formerly given less consideration.  

Taken from:
L'Osservatore Romano
Weekly Edition in English
23 January 1969, page 8

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