Transsubstantiation

Transubstantiation is a doctrine in Christian theology, most associated with the Roman Catholic Church, that describes what happens to the bread and wine during the Eucharist. According to this teaching, at the moment of consecration the substance of the bread and wine is transformed into the Body and Blood of Jesus Christ, while the appearances, taste, and other sensory properties remain unchanged. In Catholic theology, the faithful thereby receive Christ truly, albeit under the appearances of bread and wine.

The term transubstantiation derives from Latin transsubstantiatio, literally “change of substance.” The doctrine relies on a scholastic application of Aristotelian philosophy, distinguishing between a thing’s substance (its underlying reality) and its accidents (its observable attributes). The belief holds that the real change occurs in substance, not in the visible accidents of bread and wine.

Historically, transubstantiation was formally defined for the Latin Church at the Fourth Lateran Council in 1215 and reaffirmed by the Council of Trent (1545–1563) amid the Reformation debates. It is a cornerstone of Catholic Eucharistic theology and is tied to the understanding of the Eucharist as a true, substantial presence of Christ.

Other Christian traditions have offered different interpretations of Christ’s presence in the Eucharist. Some Protestants describe a spiritual or symbolic presence rather than a change in substance, while Lutherans speak of a real presence through sacramental union. Anglicans and Eastern Orthodox Christians may affirm real presence with varying theological language and emphasis.

In Catholic practice, the doctrine informs the liturgy of the Mass and the reception of Holy Communion, and it remains a defining element of Catholic sacramental theology.