A while ago I noted that people on the Internet were accusing Archbishop Müller, the new prefect of the Congregation for the Doctrine of the Faith, of being an heretic himself. I also noted that I hadn't read his works but thought the charge unlikely for circumstantial reasons.
Now I'm retroactively declaring that post the first part of a series. I have one of the Archbishop's books lying beside me and others are on their way. So in occasional posts over the next few months or so, I'll be explaining what he says on some of the controversial points and what I think of it. Of course most posts of my series will be forthcoming long after all general interest in that question has dissipated.
One of the accusations against Archbishop Müller was him denying the real presence. Various small snippets from page 139 of his book Die Messe: Quelle christlichen Lebens (The mass: source of Christian life, I don't think an English version is available) are quoted as proof-texts. I'll give a somewhat more lengthy quote to give you an idea of the context:
Now misunderstandings would result in the term "body and blood", if one thought that flesh and blood stood for the physical and biological parts of the historical human Jesus. Neither does it simply mean the transfigured body of the resurrected lord, if body is took to mean simply the material dimension of humanity. A too naive usage of the usual manner of speech leads astray here, if we say a human consists of soul and body, of flesh and blood, of skin and bones. This was already the misunderstanding of some contemporaries in the face of the speech of Jesus, who calls himself the living bread from heaven and gives his flesh for the life of the world. "unless you eat the flesh of the Son of Man and drink his blood, you do not have life within you" (John 6:53). They interpreted it as if the eating of the physical body of Jesus operated as a magical charm against natural death.
In reality body and blood of Christ do not mean the material parts of the man Jesus during his lifetime or in the transfigured corporality. Here body and blood rather mean presence of Christ in the sign of the medium of bread and wine, which becomes communicatable to human perception in the here and now. As the disciples were perceptibly together with Jesus before easter, by hearing his words and perceiving him in his sensible form in a manner fitting to humans, so we now have communion with Jesus Christ, mediated through the eating and drinking of the bread and the wine. Even in the sphere of merely human relations a letter is able to demonstrate the friendship among humans and, so to say, to illustrate and embody the affection of the addressee.
But in an absolute way, God can realize his lasting historical salvic presence in Jesus Christ through the utilization of bread and wine, by making these gifts into signs of his salvic presence. This is a transsubstantiation of the gifts of bread and wine. The natural essence of these gifts does not consist in what can be identified as their last building blocks through natural science. The essence of these gifts can only be understood in their relation to Man. The determination of the essence of bread and wine therefore must start out anthropologically. [... some waxing about what bread, wine, and the Eucharist mean to us...] This transubstantiation is different from the transformation of water into wine at the wedding at Cana, where the gift was transformed into a new but natural matter, as a sign of the revelation and glory of Christ as the bringer of salvation. But the transubstantiation in the Eucharistic celebration also differs from the assumption of a human nature by the eternal Son of God. For in that a human essence is not changed into the essence of God. Here the son appropriates a complete and unchanged human nature to be present and act through it in human history.
So the transsubstantiation is about bread and wine changing from natural media of communication into a new way of supernatural communication between God and humanity with the goal of conveying the salvation that happened in Jesus Christ in real history. So Christ is really present in an objective way, because God alone sets the objective horizon before which the reality of the world, and history, and the way of his kenosis can be viewed. But only the believer realizes this secret of the self-relinquishing love of God and only the believer now really receives friendship with Christ.
(Pp. 139-141, my translation.)
By the way, the entire book sounds like that. The guy really writes very firmly in the genre of German academic theology. But let's forget about the accidents and get to the substance: The accusation is that Archbishop Müller thinks the Eucharist is a sign rather than a substance. That charge doesn't make much sense within Müller's metaphysics, because he thinks substances are signs. He understands creation as an act of divine communication:
Creation already means more than a merely cosmological event at some temporal beginning. Creation originally means self-communication and disclosure of God to a non-devine reality. God communicates himself to man in a personal dialog through the things belonging to the world.
(P. 137, my translation again)
Basically being something is being communicated through by God in a manner fitting to that something. That's a claim not only about the Eucharist but also about all other objects. The signs are not arbitrary, because the very existence of an object consists in God using it as a sign. So the Eucharist is a sign, but the bread was a sign too.
This understanding is fully consistent with the teaching of the Church. The host previously was bread and after transsubstantiation is the body of Christ and "is" has the same meaning both times. In other words the accusation of denying the doctrine of the real presence is flat out false.
On the other hand, this understanding of substance is just Archbishop Müller's opinion and not part of the faith. And personally I'm unconvinced.
I'm happy to accept divine communication as a substantial property of many substances, but not as the only one of all substances. Many objects exists outside the light cone of any sentient creature subsisting in matter and thus can't communicate anything. They are nevertheless real. Also, if we were to interpret viruses as essentially messages from God to us, that would raise some serious questions about his character.
So I'll go out on a limb and say the theory is wrong, but there is still an enormous difference between wrong and heretic.