What is consubstantiation?
Question 09066
Consubstantiation is the term commonly used to describe the Lutheran view of Christ’s presence in the Lord’s Supper. It represents a middle position between the Roman Catholic doctrine of transubstantiation and the memorial view held by Baptists and many evangelicals, and understanding it helps clarify both what Lutherans believe and why the memorial position offers a more faithful reading of the biblical text.
What Consubstantiation Teaches
The doctrine holds that the body and blood of Christ are genuinely, physically present “in, with, and under” the bread and wine, without the bread and wine ceasing to be bread and wine. Unlike transubstantiation, which claims the substance of the bread is replaced entirely by the substance of Christ’s body, consubstantiation holds that both substances coexist simultaneously. The bread remains bread, and the wine remains wine, but the body and blood of Christ are truly present alongside them. Luther’s analogy was of iron placed in fire: the iron remains iron and the fire remains fire, but both are present together in the heated metal.
It should be noted that many Lutherans prefer to avoid the term “consubstantiation” altogether, regarding it as an oversimplification of their position. Luther himself used the phrase “sacramental union” and insisted on the “real presence” of Christ’s body and blood without committing to the precise philosophical mechanism by which this occurs. The term “consubstantiation” has been applied to the Lutheran position largely by outsiders, though it remains the most widely recognised label for the view.
The Theological Reasoning
Luther’s insistence on the real, physical presence of Christ in the elements arose from his reading of “This is my body” as a literal statement. He rejected the Roman Catholic framework of Aristotelian metaphysics and the idea that the bread ceases to be bread, but he was equally unwilling to follow Zwingli in treating “is” as “represents.” For Luther, if Jesus said “This is my body,” then His body must be genuinely present. Luther grounded this further in his understanding of the communicatio idiomatum, the principle that the attributes of Christ’s divine nature are communicated to His human nature. Because Christ’s divine nature is omnipresent, Luther argued, His human body can be present everywhere simultaneously, including in the bread of the Supper. This application of the communicatio idiomatum goes considerably beyond how the principle is typically understood in Reformed and evangelical theology, where it refers to the attribution of both natures’ properties to the one Person of Christ, not the transfer of divine attributes to the human nature itself.
The Biblical Difficulties
The same exegetical problems that apply to transubstantiation apply, in modified form, to consubstantiation. The argument from Jesus’ metaphorical language throughout the Gospels (“I am the door,” “I am the vine”) remains relevant. The fact that Paul continues to call the elements “bread” after the words of institution (1 Corinthians 11:26-28) tells against any view that requires a physical presence of Christ’s body in or alongside the bread.
The Christological argument from the communicatio idiomatum raises additional concerns. The doctrine that Christ’s human body can be omnipresent pushes the two natures of Christ toward a confusion that the Chalcedonian Definition of AD 451 was designed to prevent. Chalcedon affirmed that the two natures of Christ are “without confusion, without change, without division, without separation.” To attribute omnipresence to the human nature of Christ is to blur the distinction between the natures in a way that borders on the Eutychian error of mixing the divine and human into a tertium quid, a third kind of thing that is neither fully divine nor fully human. Christ’s human body, glorified and seated at the right hand of the Father (Hebrews 1:3; Acts 7:56), is in a specific location. Its presence is real and glorious, but it is not ubiquitous.
The ascension is important here. Acts 1:9-11 describes Jesus being taken up bodily, and the angels’ promise is that He will return “in the same way.” The New Testament consistently locates the glorified Christ at the Father’s right hand, interceding for His people (Romans 8:34; Hebrews 7:25). The memorial view is more consistent with this witness: Christ is bodily in heaven; His presence with His people is mediated by the Holy Spirit; and the Lord’s Supper is the appointed means by which the church remembers, proclaims, and participates in the benefits of His death until He returns bodily.
So, now what?
Consubstantiation takes Jesus’ words at the Last Supper with an earnestness that deserves respect, and Luther’s concern to honour Christ’s presence in the Supper was genuine and pastorally motivated. The difficulty is that the view requires both a reading of “This is my body” that the broader context of Jesus’ teaching does not demand and a Christological framework that strains against the boundaries set by Chalcedon. The memorial view does not diminish the Lord’s Supper. It holds that the elements are what Christ appointed them to be: signs of His body and blood, given for the active remembrance and participation of His people, charged with the gravity of the cross and the hope of His return. No physical presence in the bread is needed to make the Supper genuinely significant, because its significance rests not in the elements themselves but in the Person they represent and the death they proclaim.
“Do this in remembrance of me.” 1 Corinthians 11:24
