Now we are back to substance. I just don’t get it.
As I’m sure you know, the Church teaches that at the consecration at Mass the whole substance of the bread is changed into the whole substance of the body of Christ, and the whole substance of the wine is changed into the whole substance of his blood. Obviously, the question can be asked, what pertains to the substance of Christ’s body and blood. Answer: the substance of Christ’s body is his very material whole body, that is, his flesh, bone, muscle, tissue, heart, etc. And the whole substance of his blood is his very material blood.
The reason why that after the consecration of the bread and wine we do not see the actual body and blood of Jesus is because by divine power, a miracle, the appearances or accidents of the bread and wine remain while the substances of the bread and wine have been changed into the body and blood of Christ. The matter of the bread and wine which is a part of the substances of the bread and wine is changed at Mass into the matter of the body and blood of Christ. What is key here is grasping the accident of quantity or extension which because it is an accident, it is not the substance. For example, the dimensions of the host we receive in communion has about a one inch diameter. These dimensions are an accident of the bread for bread can be made with other dimensions and yet it would still be bread. The dimensions of Christ’s body in heaven are obviously larger than the host but the dimensions of any material body are what is called an accident and is not part of the substance of some thing. In the eucharist, it is the substance of the bread and wine that changes but not the accidents which is apparent to sense. Accordingly, the whole body of Christ is present in the eucharist in an unextended manner by divine power and miraculously and under the dimensions of the bread that remain after the consecration. We would not think that such as what happens in the miracle of the eucharist could take place except that we believe that the bread and wine become the body and blood of Christ because Jesus said so and Jesus is God who possesses almighty power. The miracle of the eucharist is beyond anything we naturally observe in the changes and order of nature and unless God had revealed it, I don’t think we could have even hoped to imagine such a miracle. Consider that we believe that in the consecrated bread, the whole body indeed the whole Christ is present in the host and whole and entire under every part of the host without leaving heaven. And not only in one host or on one alter, but in every host throughout the entire world.
Concerning the Real Presence of Christ in the eucharist on the USCCB website it says:
" In the Church’s traditional theological language, in the act of consecration during the Eucharist the “substance” of the bread and wine is changed by the power of the Holy Spirit into the “substance” of the Body and Blood of Jesus Christ. At the same time, the “accidents” or appearances of bread and wine remain. “Substance” and “accident” are here used as philosophical terms that have been adapted by great medieval theologians such as St. Thomas Aquinas in their efforts to understand and explain the faith. Such terms are used to convey the fact that what appears to be bread and wine in every way (at the level of “accidents” or physical attributes - that is, what can be seen, touched, tasted, or measured) in fact is now the Body and Blood of Christ (at the level of “substance” or deepest reality). This change at the level of substance from bread and wine into the Body and Blood of Christ is called “transubstantiation.”
The Catechism of the Council of Trent also uses the philosophical terms of substance and accident in expounding on the doctrine of transubstantiation.
So, in order to understand the Church’s doctrine of transubstantiation which is the change that takes place of the bread and wine at Mass, I think we need to understand in some degree what is meant by the philosophical terms of substance and accident (or appearances) which the Church has deemed useful in expounding the doctrine of transubstantiation which is in accord with the Church’s faith concerning the Real Presence of Christ in the eucharist. At the same time, I think we should also keep in mind that our faith in the Real Presence does not depend on any philosophy but on the words of Jesus Christ himself. However, transubstantiation (change of substance) is a dogma of the faith, this is what really happens. I know what I have said here may be difficult to understand upon first reading it. But it is actually not to difficult to grasp once a person understands the concepts in some degree. If you have any questions, feel free to ask.