Moment of Transubstantiation



In the Latin Church, following Thomistic theology, we generally acknowledge that the moment of Transubstantiation occurs at the Words of Institution (This is my Body; This is my Blood). We acknowledge this in the Liturgy by the elevation of the now consecrated Body and Blood. My question is - is this just the de facto understanding based on Thomistic theology being the de facto school of theology for the Latin Church or is this moment of consecration an infallible teaching of the Church?


The subject of the Mass, the Eucharist, and specifically the Real Presence brought about by Transsubstantiation was an important issue at the Council of Trent, in order to respond to the “Reformers”.

I don’t have all the specific Canons concerning this, but I believe it was defined “DeFideDefinita” at the XIIII Session, canon 4 of the Council of Trent: "And because Christ 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 Transsubstantiation."
In other words, it is onlhy by such a total conversion of the substance of the bread and wine into the substance of our Lord’s body and blood that his words, “This is my body; this is my blood” can be verified.
It was important for Trent to express what had been taught for centuries, and I think they nailed it. Transubstantiation was not a Scholatic question, according to Pius VI, it has been defined by the Council of Trent as an article of faith.



1377 The Eucharistic presence of Christ begins at the moment of the consecration and endures as long as the Eucharistic species subsist. link

1413 By the consecration the transubstantiation of the bread and wine into the Body and Blood of Christ is brought about. Under the consecrated species of bread and wine Christ himself, living and glorious, is present in a true, real, and substantial manner: his Body and his Blood, with his soul and his divinity (cf. Council of Trent: DS 1640; 1651). link

So when the priest says “This is my body” Jesus is the bread and when he says “This is my blood” Jesus is the wine. (I always begin to feel ‘different’ during the Sanctus, though.)



Generally speaking, in the history of the doctrines of the Catholic Church three stages may be distinguished. There is the first period during which the truth is in serene and undisputed possesion; then follows a period of discussion when the truth is attacked by heretics, a period which usually culminates in a solemn definition of the Church by which the meaning of revelation is put beyond all possibility of misunderstanding. The doctrine of the real presence had indeed been attacked before the 16th century, but never had it been so fundamentally and categorically denied as it was by the heretics of the Reform. Already St. Paul had pointed out that the Eucharist is the symbol and the cause of ecclesiastical unity (1 Corinthians 10:17); St. Ignatius of Antioch appealed on the same grounds to the Docetists of the 1st century to avoid schisms, and " to use one Eucharist, for one is the flesh of our Lord Jesus Christ and one the chalice unto communion of his blood; one is the altar, and one its bishop together with the priests and deacons." (Ad Philadelphia, chapter 4) It is not surprising, therefore, that the great schism of the Protestants should have been inaugurated by a vehement attack upon the sacrament of our Lord’s Body and Blood. The Council of Trent (Session 13) in condemning the errors of the Reformers has given us a clear and unequivocal statement of the Eucharistic dogma.

Some additional information to what has already been posted.




I am not questioning the doctrines of the Real Presence, Transubstantiation, or anything else like that.

My question is, is the moment when the Latin Church recognizes the consecration having taken place in the Liturgy - at the Words of Institution - is this a theological opinion or a matter of infallible faith?

The Catechism quotes and such state that Christ is present after the Consecration - not questioning that. But it isn’t specific on the exact moment that the consecration takes place, which Thomistic theology ascribes to the Words of Institution.

In the Eastern Catholic Churches, they don’t pinpoint it to a precise moment, it occurs sometime during the Eucharistic Prayer. If you really press them, some might point to the Epiclesis.

Also, the Vatican in 2001 said that the Anaphora of Addai and Mari can be considered valid, even though it doesn’t contain the Words of Institution.

I repeat - I am NOT questioning the doctrines of the Real Presence or Transubstantiation or that the Priest during the Mass confects the Eucharist! I whole-heartily confess my belief in these and every other belief that Holy Mother Church declares as part of the infallible Catholic Faith.

So again my question is:

Is considering the precise moment when Transubstantiation occurs a theological opinion and hypothesis or is it a matter of infallible faith?


I hear what you are saying, and I indeed think it is interesting. I offer my own opinion, and it is just that, opinion.

The highest level of belief is ‘de fide definita’, which means as Catholics we gotta believe it. When it is a defined doctrine of faith, that is God telling you, ‘this is the truth’.

Trent declared and defined it is at the words of consecration, transsubstantiation occurs. Pius VI declared that Trent’s statement is not scholatic opinion, but defined, doctrinal truth.

The Epiclesis which occurs in our own Latin Rite is not the point or points where Transsubstantiation occurs. It occurs with the words of Consecration, that’s what Trent said, and which I believe.

Now as far as the Anglican rite, the Holy See has declared that Anglican orders are invalid, so it is begging the question to even ask about their words of institution. (Likewise Lutheran orders).

As far as the Eastern rite is concerned, we know that their priestly and episcopal orders are valid, and so also is their Mass and Consecration.

Where the latter fits in with Trent, I don’t know. The Vatican opinion in 2000 does not carry with it a high level of belief, that is, if I have strong opinions to the contrary, I dont have to accept their statement. Not so the decress of Trent. If there are other theological grounds, they have to be taken into account.
I don’t know of any. I will have to research it and mull over it.


I don’t have a source for this, but I recall one of our priests telling an RCIA class that there is no defined moment for this. It is bread and wine when offered up at the Offertory and the Eucharist when elevated at the end of the Eucharistic Prayer.



I refer you the the Canons of the Council of Trent, Session XIII. It is explicitly at the words of Consecration that Transsubstantiation (The Real Presence) occurs. That’s a defined doctrine of the Faith. Not at the Elevation of the Host, not at prayers in the Mass before the Consecration, or words afterwards.

I quoted Trent exactly in another post on this.

I am researching the Epiclesis question of the Eastern rite…




The text of Trent reads:

Session XIII Chapter IX

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.

It doesn’t say the Words of Consecration, less even the Words of Institution. It says by the Consecration. So it doesn’t answer that question, at least the way I am reading it, of when (if any is infallibly defined) precisely this consecration occurs. It doesn’t even answer if it is a precise instantaneous event or if it just occurs in the course of the Eucharistic Prayer.

The Trent Catechism does seem to indicate that the consecration occurs at the Words of Institution, but the question remains on whether it expresses the de facto teaching of the day (Thomistic theological viewpoint) or the infallible teaching of the Church.


i always assumed it was after the santus when we all hit our knees…



One part of my answer on the question of what words bring about Transsubstantiation, I am entirely certain we are talking about the words: This is my Body…This is my Blood".

We are not talking about words which have some subjunctive mood in them, like" Pray, brethren, that our sacrifice
May be acceptable to God, the almighty Father
May the Lord accept the sacrifice at your hands
For the praise and glory of his name,
For our good and the good of all his Church",

or "Bless and approve our offering: make it acceptable to you, an offering in spirit and in truth. Let it become for us the body and blood of Jesus Christ, your only Son, Our Lord.

Those are not the words of institution, the words of Christ at the Last Supper.

Every sacrament has what is called “Matter” and “Form”, so in Baptism, the “matter” is the water, and the “form” are the words"
“I baptise you, in the name…”

In the Eucharist, we have matter and form: The matter is the bread and wine, the elements. The form are the words, “This is my Body”, “This is my Blood…”

As for Epiclesis, the Church teaches ‘de fide’ that transubstantiation is effected by Christ words. as is clear from the fact that in the Roman Missal there is no true epiclesis. Catholic theologians teach that the sacrifice in all its essentials is complete as soon as the words of institution have been pronounced over the chalice, that is, after the two-fold consecration of the bread and wine has taken place.

What are the words of institution - the words Christ used when instituting this Sacrament.



Provided by an earlier poster, the documents referenced are from the Synod of Bishops in preparation of the recent Year of the Eucharist:

Lineamenta, 30
According to our Catholic faith, the form of the Sacrament is the words of consecration “This is My Body…This is My Blood”], which are essential and solely necessary.

Lineamenta, 37
The Institution of the Eucharist
From the beginning, the Church solemnly fulfills the Lord’s actions, coming to understand them by meditating on them one by one, as if to be instructed over and over again in their meaning: the presentation of the Gifts, the consecration, the breaking of the bread and the distribution of Holy Communion.[138] For this reason, the words “Take and eat” are not followed by the breaking of the host. If this be done, that moment would immediately become communion. Instead, at this highly charged mystical moment, the liturgy indicates that the celebrant is to bow his head and pronounce the words with a clear, moderate voice so as to promote contemplation, as does the Bishop on Holy Thursday, when he breathes over the Oil of Chrism. “By his actions and by his proclamation of the words, he (the celebrant) should impress upon the faithful the living presence of Christ.”[139] At this moment, indeed, the sacramental Sacrifice is accomplished.

Lineamenta, 38
The Epiclesis over the Consecrated Gifts
The Church Fathers, who maintained the importance of the epíclesis to the Spirit, thought to unite it to the words of institution to render the sacramental sign complete. The Lord’s words are spirit and life (cf. Jn 6:63). Christ works together with the Holy Spirit, while remaining the one consecrator of the Eucharist and the dispenser of the Spirit. The Council of Trent has established that the epiclesis is not essential to the validity of the Eucharist.

Instrumentum Laboris, 37
Transubstantiation takes place in the consecration of the bread and wine.

Instrumentum Laboris, 48
**At the centre of the Eucharistic Prayer are the Lord’s words of institution over the bread and wine. This is the consecration, the solemn moment when the Risen Lord becomes really present under the elements of bread and wine. **


Excellent post, Fidelis.

I was never that familar with “Epiclesis”, and I appreciate your information


In case of the ancient Anaphora of Addai and Mari , validity was granted because

“… the words of Eucharistic Institution are indeed present in the Anaphora of Addai and Mari, not in a coherent narrative way and ad litteram, but rather in a dispersed euchological way, that is, integrated in successive prayers of thanksgiving, praise and intercession.”

(Guidelines for admission to the Eucharist between the Chaldean Church and the Assyrian Church of the East, 2001 October)

As per the Catechism of Church, Words of Eucharistic Institution is necessary for transubstantiation.

CCC Article 1333:

“At the heart of the Eucharistic celebration are the bread and wine that, by the words of Christ and the invocation of the Holy Spirit, become Christ’s Body and Blood.”


The teaching of the Eastern Catholic Church is that it occurs at the Epiclesus.


See also this thread with lots of links, very in-depth on the matter. It seems to me that there is no immutable “definition” of a single “moment.” As Ignatius said, the East emphasizes the Epiclesis. The link I provided here goes into that as well as some theologians discussing it.


[quote="mcs7474, post:10, topic:81140"]
i always assumed it was after the santus when we all hit our knees...


Yea, I just duck... er... I mean... ummm.... keep my head bowed the whole time.



As I understand, there was never a debate in the early church as to the exact point of transubstantiation. So if you read some early fathers, it may seem Epiclesis was considered as the moment of transubstantiation, and many others would imply Eucharistic words as the consecration.

Though there is no invoking of Holy Spirit in the Roman missal, but the explicit words of institution is as well an epiclesis, because in John 6/63, Jesus tells that the words of Jesus is full of Spirit.

“The words I have spoken to you—they are full of the Spirit”

In other words, Eucharistic words of institution is sufficient for transubstantiation. In many Eastern Catholic Churches, however, there is both ad litteram institutional words as well as Epiclesis, which has become a source of confusion.

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