In this post I will try to explicate the real presence.
1. Let's define the real presence as the spatial localization of Christ's physical body in, with, or at the communion elements (e.g. bread, wafer, cup of wine or grape juice). I think that's an accurate definition.
In addition, this doctrine requires his body to be simultaneously present at multiple, disconnected locations.
2. The doctrine of the real presence generates a dilemma. Proponents think the NT clearly teaches the real presence. In their view, that's the face-value meaning of Jn 6 and 1 Cor 11. Yet, on the face of it, the bread and wine bear no resemblance to a human body.
So there's a fundamental tension in their position. On the one hand they appeal to what they deem to be the common sense interpretation of their prooftexts. On the other hand, this, in turn, forces them to reject a common sense understanding of what it means for a body to be present–or for a body to be a body. They must treat the real presence as an empirical illusion.
3. Many of them simple override philosophical objections by appealing to divine omnipotence. It's a miracle, so we shouldn't judge it by ordinary standards.
That, however, is too facile. Christians need to respect the integrity of miracles. A miracle isn't just any crazy thing you can postulate. A miracle isn't a get-out-of-jail-free card. Christians bring the concept of the miraculous into disrepute by abusing that concept to defend any intellectual objection to their position.
In the case of the real presence, even if it is a miracle, it employs natural elements. The communion elements (bread and wine) are natural elements. Likewise, the body of Christ is a natural organism. Even the glorified body of Christ is still a natural organism.
If God works with or works through a natural medium, then that imposes limitations on what he can do by that means. God can achieve an effect apart from natural means, but if he confines himself to a natural medium, then that restricts his field of action. Defaulting to omnipotence won't remove the obstacle, for this is not a question of what God can do, but what a natural medium can do.
4. There are two basic models of the real presence:
The body of Christ is present in or with the communion elements. The bread and wine might contain his body. His body might be united to the communion elements. They commingle. Something like that.
The body of Christ takes the place of the communion elements. The secondary properties are bread and wine, but the primary qualities are the body of Christ.
5. Both these models suffer from comparable challenges:
i) How can one body be simultaneously present in separate places?
In theory, Christ could have multiple bodies. Since the Son is illocal and the soul is illocal, it's metaphysically possible for the Son of God and his human soul to be in union with duplicate bodies.
But even if that's possible, in reality, Jesus only has one body. Yet in the nature of the case, a physical body is spatially continuous. It has physical boundaries. There's my body, and then there's what surrounds my body. My body begins and ends. If, however, the body of Christ is multiply-instantiated at discontinuous locations, then it can't be the same (singular) body.
6. In addition, there's the problem of scale. The body of Jesus is over five feet tall. Well over 100 pounds. How can a wafer contain his body? Or if the wafer simply is his body in disguise, how can a human swallow his body whole? Mental images of a python swallowing a pig spring to mind.
These aren't carping criticisms. These aren't facetious objections. This is taking the doctrine seriously, and considering what that entails.
i) One theory might be miniaturization. That could take two forms:
a) Shrinking a body by reducing the number of cells.
b) Shrinking the size of the cells.
I'm reminded of a movie I saw as a kid: The Fantastic Voyage, where a patient undergoes brain microsurgery by miniaturizing a medical submarine crew.
There are, however, problems with miniaturization:
If (a), then a human brain with far less mass can't do the same job as a normal human brain. If it has fewer brain cells by orders of magnitudes, it can't perform same functions. It lacks the physical complexity.
If (b), our cardiovascular system is designed to process oxygen molecules. The scale of the cardiovascular system is calibrated to the scale of oxygen molecules. If you drastically reduce the scale of the cardiovascular system, it can't process oxygen molecules.
Now, a sacramentalist might counter that the "laws" of physics and biochemistry are contingent. God could change that.
I agree. That, however, involves treating the body of Christ as a closed-system. Yet a living, breathing body is an open system. There's a continuous interchange between the body and its environment.
ii) Another theory might be to grant that Christ's body is on a normal scale, but punt to a miracle. But I don't think that will suffice.
Take the question, Can God make a box that's bigger on the inside than the outside? Seems to me the answer is no. Invoking omnipotence doesn't help, for if God works through a medium, then the nature of the medium will impose restrictions on what can be done via the medium.
Is it not physically impossible for a box to be bigger on the inside than the outside? How can a 3D object be larger than what contains it? Is that not an analytical truth?
And even if there were abstract geometries in which that's possible, to my knowledge, our universe does not exemplify that counterintuitive geometry.
Perhaps a sacramentalist might postulate that God miraculously creates pockets in the universe which exemplify a different geometry from the universe as a whole–like intrusions of a parallel universe. But even if that's possible, the Eucharist is not a closed system, but an open system. It must intersect with the communicant.
7. In any event, why resort to such esoteric metaphysics? Is that really the function of the Eucharist in Scripture?
For adherents of sacramental realism, the Eucharist is said to be, or contain, the glorified body of Christ. The body of the risen Christ.
If, indeed, you subscribe to the real presence, then I think that's unavoidable. What other body would it be? Not the body he had before the Resurrection, but the body he had after the Resurrection. That, after all, is the only body he currently has. There's a sense in which his mortal body no longer exists. It died.
To be sure, there's considerable continuity between his mortal body and his immortal body. For one thing, his mortal body was only dead for about 36 hours.
Still, there's a basic difference between the two: his glorified body is immortal. Ageless. Disease free. His glorified body is not a return to the status quo ante. Rather, it marks an advance over the status quo ante. Something better.
To say, however, that that's what is meant by the Eucharistic body and blood of Christ in Scriptural usage massively misses the point. For the point is not that Jesus had real hemoglobin flowing through his veins. Although that's essential to the integrity of the Incarnation and Resurrection, that's not what's significant about the body and blood of Christ from a redemptive standpoint, which the Eucharist illustrates.
It isn't blood, per se, but shed blood. Not a deathless body, but, to the contrary, a body that's put to death. The significance lies in the notion of sacrificial death. Violent death. That's an essential component of vicarious atonement. The Redeemer dies on behalf of others, in their place.
The Eucharist doesn't represent the Risen Christ, but the crucified Christ. Not Christ on Easter, but Christ on Good Friday. The Eucharist represents Christ on the cross, at Calvary.