What Is Transubstantiation?
Transubstantiation is the change of the whole substance of bread and wine into the Body and Blood of Christ, while their outward appearances remain.
It is the Catholic Church's precise term for how the Real Presence comes about. The word was used dogmatically at the Fourth Lateran Council (1215), explained by St. Thomas Aquinas, and defined by the Council of Trent (1551). Below are the primary sources, in order.
Key facts
- Definition (one line)
- The change of the whole substance of bread and wine into the Body and Blood of Christ; the outward appearances remain.
- Tradition
- Catholic Church (also held by Eastern Orthodox under different terminology)
- First dogmatic use
- Fourth Lateran Council, 1215
- Classic theological explanation
- St. Thomas Aquinas, Summa Theologiae III, q. 75 (13th century)
- Solemn definition
- Council of Trent, Session XIII, 1551 (Decree on the Most Holy Eucharist)
- Relationship to "Real Presence"
- "Real Presence" is the belief that Christ is truly present in the Eucharist. Transubstantiation is the Church's technical term for how that presence comes about.
- Catechism reference
- CCC §1376
Common questions
What is transubstantiation in simple terms?
Transubstantiation is the Catholic teaching that, when a priest consecrates bread and wine at Mass, the entire substance of the bread and wine is changed into the substance of the Body and Blood of Jesus Christ, while the outward appearances ("accidents" — taste, shape, color) of bread and wine remain. It is the Church's precise term for how the Real Presence comes about.
When was transubstantiation defined by the Catholic Church?
In three stages. The word "transubstantiation" was used dogmatically at the Fourth Lateran Council in 1215. The classic philosophical explanation was given by St. Thomas Aquinas in the 13th century (Summa Theologiae III, q. 75). It was solemnly defined by the Council of Trent in 1551, in response to the Protestant Reformation, in the Decree on the Most Holy Eucharist.
What is the difference between transubstantiation and the Real Presence?
The Real Presence is the belief that Jesus Christ is truly present in the Eucharist — body, blood, soul, and divinity. Transubstantiation is the technical Catholic term for how that presence comes about: the substance of bread and wine becomes Christ's Body and Blood while the appearances of bread and wine remain. The Real Presence was believed from the beginning; transubstantiation is the later word that names the change.
St. Paschasius Radbertus
c. 830“Understand that these spiritual realities that are indeed neither locally nor carnally before the sight are borne up to the heights of the divine majesty. Think then whether any corporeal thing could be more sublime since the substance of bread and wine is effectively and interiorly changed into the flesh and blood of Christ, so that after the consecration it is rightly believed to be truly the very flesh and blood of Christ and nothing other than Christ”
On the Body and Blood of the Lord · about St. Paschasius Radbertus
Bl. Lanfranc of Canterbury
c. 1070“We believe that the earthly substances on the altar of the Lord, placed there for divine consecration by the priestly ministry, are ineffably, incomprehensibly, and wonderfully overturned by a heavenly power, and converted into the essence of the Body of the Lord, preserving the appearance and qualities of the species. [...] This is the faith that was held in ancient times and is now held by the Church, and has spread throughout the entire world by those of the Catholic name.”
De corpore et sanguine Domini · about Bl. Lanfranc of Canterbury
Peter Lombard
c. 1150“And so after the consecration the substance of bread and wine is not there, although the species remain, for the species of bread and wine are there, as indeed is their taste, so that “one thing is seen, another is understood."”
The Sentences. Book 4, The Mystery of the Trinity · about Peter Lombard
“His body and blood are truly contained in the sacrament of the altar under the forms of bread and wine, the bread and wine having been changed in substance, by God’s power, into his body and blood. ”
Canon 1 · about Fourth Lateran Council
St. Thomas Aquinas
c. 1270“Some men accordingly, not paying heed to these things, have contended that Christ's body and blood are not in this sacrament except as in a sign, a thing to be rejected as heretical, since it is contrary to Christ's words.”
Summa Theologica · about St. Thomas Aquinas
Nicholas of Cusa
15th century“And then from wondrous charity, which Christ shows to us in this sacrament, with which He, about to pass from the world [Jn. 13:1], left Himself as food in a wondrous manner, the most wondrous of all His miracles.”
Sermon XVIII de Eucharistia · about Nicholas of Cusa
Council of Trent
1545–1563“If any one denieth, that, in the sacrament of the most holy Eucharist, are contained truly, really, and substantially, the body and blood together with the soul and divinity of our Lord Jesus Christ, and consequently the whole Christ; but saith that He is only therein as in a sign, or in figure, or virtue; let him be anathema.”
Session XIII, Canon I · about Council of Trent
Frequently asked questions
What is transubstantiation in simple terms?
Transubstantiation is the Catholic teaching that, when a priest consecrates bread and wine at Mass, the entire substance of the bread and wine is changed into the substance of the Body and Blood of Jesus Christ, while the outward appearances ("accidents" — taste, shape, color) of bread and wine remain. It is the Church's precise term for how the Real Presence comes about.
When was transubstantiation defined by the Catholic Church?
In three stages. The word "transubstantiation" was used dogmatically at the Fourth Lateran Council in 1215. The classic philosophical explanation was given by St. Thomas Aquinas in the 13th century (Summa Theologiae III, q. 75). It was solemnly defined by the Council of Trent in 1551, in response to the Protestant Reformation, in the Decree on the Most Holy Eucharist.
What is the difference between transubstantiation and the Real Presence?
The Real Presence is the belief that Jesus Christ is truly present in the Eucharist — body, blood, soul, and divinity. Transubstantiation is the technical Catholic term for how that presence comes about: the substance of bread and wine becomes Christ's Body and Blood while the appearances of bread and wine remain. The Real Presence was believed from the beginning; transubstantiation is the later word that names the change.
Do Catholics believe in transubstantiation?
Yes. Transubstantiation is the dogmatic teaching of the Catholic Church on the Eucharist, defined at the Fourth Lateran Council (1215) and the Council of Trent (1551). It is binding doctrine for all Catholics. The Catechism of the Catholic Church (§1376) states: "The Council of Trent summarizes the Catholic faith by declaring: ‘…by the consecration of the bread and wine there takes place a change 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.' This change the holy Catholic Church has fittingly and properly called transubstantiation."
What did Thomas Aquinas say about transubstantiation?
St. Thomas Aquinas, in Summa Theologiae III, q. 75, gave the classic philosophical account of transubstantiation. Using Aristotelian categories, he distinguished between the "substance" of a thing (what it fundamentally is) and its "accidents" (its observable properties — color, taste, shape). In transubstantiation, the substance of bread and wine is converted into the substance of Christ's Body and Blood, while the accidents of bread and wine miraculously remain. Aquinas insisted this is not a physical or chemical change, but a substantial one — accessible to faith, not to the senses.
The doctrine named here was believed long before the word existed.
What science finds inside the host
When the Church has sent examined hosts to a laboratory, the answer keeps coming back the same: human heart muscle, type AB blood. The doctrine of transubstantiation meets the evidence in the catalog of Eucharistic miracles.