The view seems to be rather widespread that transubstantiation is a theological opinion but not an official Catholic teaching. One who holds this view may insist that Christ's real presence in the Eucharist must be believed as an article of faith, while the way in which he is present has not been determined by the Church's magisterium, but is left open to debate by theologians.
That is a very surprising view, for the Church has officially taught on a number of occasions that Christ is present in the Eucharist by transubstantiation. This was solemnly proclaimed by the Council of Trent in the 16th century and has been repeated in more recent statements, including the encyclical letter Mysterium Fidei of Pope Paul VI and the Catechism of the Catholic Church.
The words of the Council of Trent could hardly be clearer: "... by the consecration of the bread and wine a change is brought about of the whole substance of the bread into the substance of the body of Christ our Lord, and of the whole substance of the wine into the substance of his blood. This change the Holy Catholic Church properly and appropriately calls transubstantiation" (DS 1642). In canon 2 the Council condemns those who deny this doctrine.
Yet some who should know better still insist that we don't have to believe in transubstantiation. Alban McCoy, a Catholic chaplain to Cambridge University, had an article in the British Catholic paper The Tablet on 18 August 2006, in which he states that while Catholics are committed to the teaching that Christ is truly present, sacramentally, in the Eucharist, "They are not however, committed to believing in the notion of transubstantiation, as such. What Trent actually says is that this is simply a most appropriate ( aptissime) way of talking about the eucharistic presence, but it does not preclude other ways that might be deemed more appropriate."
Trent does nothing of the kind. It spells out what we must believe, and anathematises the rejection of this. It does not say that transubstantiation is an appropriate way of talking about the Eucharistic presence; it says that transubstantiation is an appropriate name for this reality. The appropriateness refers to the name, not the doctrine.
An obvious question arises: Why are some Catholic scholars unwilling to accept this plain teaching? I suggest three reasons: one pertaining to science, one to philosophy and one to ecumenism.
The assertion is made that the concept of transubstantiation is based on the outmoded physics of Aristotle, and is incompatible with modern science. We'll return to that difficulty later, after looking at what transubstantiation means.
A second reason is based on a mistaken idea of what is meant by substance. The 18th century British philosopher George Berkeley thought material substance is a meaningless term and so he insisted that there is no such thing. Many philosophers have been influenced by his view, but they don't understand what St Thomas Aquinas and other Catholic philosophers mean by substance. We will come back to that also.
A third reason is related to ecumenism. After the Protestant Reformation in the 16th century a bitter attack was made on the doctrine of transubstantiation. It was denounced with a vehemence difficult to understand today. British Monarchs, at their coronation, had to publicly repudiate transubstantiation, a requirement that lasted into the 20th century.
So a misguided idea has spread in the Catholic Church since Vatican II that the word should be avoided with the Eucharistic presence explained in other ways. The problem is that throwing out the word has led to throwing out the doctrine.
Now let us look at the meaning of the doctrine of transubstantiation, starting with what common sense shows us about the material world. We get our knowledge through the five senses - sight, hearing, touch, taste and smell. But these show only the superficial aspects of things.
A cabbage, for instance, is not just a bundle of qualities that can be sensed: it is a substance which manifests itself to us through those qualities. It is a reality possessing qualities that can be sensed. A dog is not a collection of sense data: it is a substance having shape, colour and so on.
To deny the existence of a substance, or basic reality, underlying the superficial qualities like shape or size logically leaves us with shape that is not the shape of anything and size that is not the size of anything.
I've mentioned the philosopher Berkeley. He completely failed to grasp the meaning of substance as understood by Aristotle in ancient times and the Scholastic philosophers such as St Thomas Aquinas in the Middle Ages. Berkeley decided there is no such thing as substance - which left him with colour that isn't the colour of anything, shape that isn't the shape of anything, etc. So he concluded that there is no material world at all, rather, it's all in the mind. He thought we are all spirits (we have no bodies), and God puts images into our minds which people have wrongly assumed to be external things. The Yarra River or the Sydney Harbour Bridge, for instance, only exist in our minds.
There's a certain logic in Berkeley's position if we deny our common sense and say there is no reality, no substance underlying the qualities apprehended by the five senses. But if we accept what common sense tells us we see that the substance or nature of things can't be contacted by the five senses, yet must exist.
Returning to the objection that transubstantiation is based on the outmoded physics of Aristotle, it should be clear that this is not so. What transubstantiation presupposes is that there exists a reality, an essence, underlying the phenomena perceived by the senses - and as noted, that is a matter of common sense. Modern physics doesn't deny this, but is a study of the phenomena attained by the senses and through the use of microscopes and other scientific aids.
Now coming back to the doctrine of the Eucharist: the substance (or nature or essence) of bread is changed by divine power into the substance of the body of Christ and the substance of wine into the substance of his blood. This change is supernatural and is possible only to the infinite power of God.
Pope Paul VI, in his encyclical Mysterium Fidei, n. 51, quotes the words of St Ambrose: "If Christ's word, then, could make out of nothing what was not previously in existence [when he created the world], is it incapable of changing existing things into what they were not before?"
Reason tells us there is a substance or underlying reality which our five senses can't reach, but the mind learns much about this reality through the senses. For instance, we know what a cabbage is or what a dog is, but the senses show only phenomena such as colour and size and shape.
Now, when the priest says the words of consecration, the substance of bread is changed into the substance of Christ's body, and the substance of wine into that of his blood. But the appearances (the accidents, to use the technical term) remain unchanged. So there is no way of detecting the change; it is known by faith, not by observation.
The soul and divinity of Jesus Christ are of course inseparably united to his body and blood, so he becomes present in his complete reality. It is a supernatural mode of presence, but is just as real as was his presence when he walked by the Lake of Galilee. As the Catechism of the Council of Trent says, this sacrament contains "...all the constituents of a true body, such as bones and sinews...".
Solution of difficulties
Some critics claim that eating Christ's body and drinking his blood, if his body and blood were really there, would be cannibalism. They would be right if Christ were there in the natural way in which he was present during his life on earth and the way in which he is present now in heaven. But his Eucharistic presence is supernatural, "in the mode of substance", as the theologians say. So there is no question of cannibalism.
This special mode of presence solves another difficulty: Why doesn't he suffer when the communicant eats him? Sometimes the answer is given that a glorified body can't suffer but that would not explain why he didn't suffer at the Last Supper, when his body was not yet glorified. The correct explanation is that this supernatural way of being present excludes the possibility of suffering.
For the same reason he can be in many places at the same time: the supernatural manner of his presence doesn't tie him down to one place.
Back in the 19th century Lord Macaulay, who was not a Catholic, saw the Real Presence as the acid test of faith: a person who could believe that, he thought, could believe any doctrine. Actually it is not that difficult to accept if one sees that our natural knowledge can't settle the question one way or the other, so we are not going against reason in accepting it through faith in Christ.
Yet many Catholics today don't believe in the Real Presence, as surveys have shown. They are like those early disciples who said: "This is a hard saying who can listen to it?" (John 6:60).
An understanding of what transubstantiation means will lead to a more vivid awareness of Jesus' presence in the Eucharist and a deeper devotion to him. He loves each of us so much that he makes himself as really present to us as he was to his friends when he lived in Galilee the manner of his presence is different but it is not less real.
As soon as the priest, acting in persona Christi, says the words of consecration, the glorious body, blood, soul and divinity of Christ become present on the altar. He remains really present in the tabernacle. In Holy Communion he enters into the communicant and his Eucharistic presence remains until the host dissolves.
In this mortal life our limited minds are incapable of fully grasping the glory of the Real Presence, but we should strive to enter ever more fully into this great mystery. In Holy Communion the Divine Word, the infinite God, enters into me: his body, blood, soul and divinity.
Father Walker, who prepared G.K. Chesterton for his First Communion, wrote of the occasion: "It was one of the most happy duties I had ever to perform ... That he was perfectly well aware of the immensity of the Real Presence on the morning of his First Communion can be gathered from the fact that he was covered with perspiration when he actually received Our Lord. When I was congratulating him he said, 'I have spent the happiest hour of my life'.'' (Quoted by Maisie Ward in her book Gilbert Keith Chesterton, Penguin Books edition, p. 384).