Recently, while leading a small group of people around "the holy places" of France, some of us visited the magnificent romanesque Basilica of St Sernin at Toulouse, in the south of that country.
Until relatively recently, the great Italian Dominican theologian of the 13th century, St Thomas Aquinas, was buried here.
One of the most significant contributions of Aquinas to Catholic theology was, I believe, his formulation of the term "transubstantiation", by which he meant the process of the change of mere bread and wine into the Body and Blood of Jesus during the Consecration of every Mass following the command of Jesus at the Last Supper, known as Holy Thursday, the day before Good Friday, when he suffered his Passion and death on the Cross.
As we all know, it is impossible for us to describe in mere human terms what actually takes place during the Consecration, a profound and wonderful mystery, but to the Catholic Church, St Thomas' formulation of transubstantiation appears to be the best way to describe this mysterious process.
Now, as a Hebrew Catholic, I am very conscious of the meanings of the English word "body" in Hebrew (the Jewish liturgical language at the time of Jesus and even now), and Aramaic (the vernacular used by Jesus and other Jews, during his time on earth). As with other languages, Hebrew and Aramaic, not surprisingly, have many words with more than one meaning: shalom, "peace", for example, has at least 16 meanings!
Thus, the Hebrew word for "bodv" also means "substance", whereas in Aramaic it also means "the very thing".
Indeed, it is said that there are at least 120 ways to explain Jesus' words of Institution!
I believe that if any of the medieval Scholastics, like St Thomas Aquinas, had asked the nearest Jew as to what the word "body" means in Hebrew and Aramaic, all the vast effort and ceaseless arguments during the Scholastic period could have been more easily resolved.
Worst of all was the hideous blood-letting Thirty Years' War in the 17th century, when vast numbers of Christians, whether Catholics or Protestants, murdered each other, all professing to do it in the the name of God — a monstrous blasphemy! Very often those eight little words (in English), "This is my Body" and "This is my Blood", were ostensibly the cause, or merely the excuse for such un-Christian behaviour.
As I said, if ex-Father Martin Luther, lawyer John Calvin, ex-Father Huldrich Zwingli, or ex-Father John Knox, had consulted with any Jew who spoke, or just understood Hebrew, and knew the secondary meanings of "body" in Hebrew and Aramaic, much of their fighting among themselves, to say nothing of with Catholics, could or should have been avoided.
But of course, what would an "unbelieving" Jew know of Christian theology? Not much at all but he certainly knew the secondary meanings of "body" in Hebrew and Aramaic.
I believe that this could have helped resolve, or could still help in resolving at least some of our major differences which largely derive from the Protestant Reformation of the 16th century.
Furthermore, this would fulfil Jesus' words, "That all may be one" (John 17:21).
You will of course notice that it is only the "apostolic" churches, of the east and west, which fully believe in the Real Presence of Jesus in the Eucharist; and there are, of course, Anglo-Catholics who also hold this belief. On the other hand, Lutherans believe in consubstantiation, namely, that in the Eucharist Jesus is truly present, but so are the bread and the wine; further, as Holy Communion comes to an end, Jesus is no longer present.
In the Catholic Church, of course, we believe that Jesus is really and truly present until consumed by the priest and congregation: whatever Hosts are "unused" are then reserved in the Tabernacle. This goes back to the time of the Roman Empire, when, due to persecution, Hosts where given to members of the congregation to take back to the sick, who could not attend "home" churches, as none existed until the Emperor Constantine gave toleration to Christians in the the fourth century. Of course, the taking of Hosts to the sick continues today.