Thomas More, whose birthday it is today (7 February), was a strong defender of Catholic eucharistic theology. In his Answer to a poisoned book (1533), a reply to a Zwinglian tract probably written by George Joye, he wrote:
I shall, beside all such spiritual expositions as this man useth therein by way of allegories or parables, declare you the very literal sense of those words, "My flesh is verily meat, and my blood verily drink": so that that ye may see thereby that our saviour verily spake and meant, not only such a spiritual eating as Master Masker saith he only meant, but also the very bodily eating and drinking of his very flesh and blood indeed. 1
The basic dispute depends upon what the meaning of the word "is" is, in the words of institution, and in other passages like the one quoted (John 6:55). Zwingli and Joye thought it meant "signifies". More asserts (among other arguments) that since Jesus had a body of flesh and blood, "This is my body" admits a literal reading, unlike when Jesus elsewhere says that he "is" a vine, a door, and so on. He says that although there are also symbolic meanings, a literal one cannot be wholly dismissed, since that would mean ignoring the plain words. Moreover, although one has to go to some effort to explain how it's possible (how Christ's body can be present in the Eucharist, at many places and times, appear as bread, etc.), it's more acceptable to believe in miracles than to remove all literal meaning from "is".
At first glance this seems to be the same kind of argument made by Biblical literalists today about many other passages. Does More's reasoning - that it is necessary to find some plain reading if at all possible - count as a "literal" argument, according to a modern understanding about what that means? What rules or safeguards are present in the modern approach, whereby self-described literalists today are generally not led to consider transubstantiation a viable option in this case, when supernatural explanations are accepted in other cases?
1. The answer to the first part of the poysoned booke whych a nameles heretike hath named the supper of the Lord, 1.3. In The workes of Sir Thomas More ... in the Englysh tonge (London, 1557), p1042. Spelling and punctuation modernised by me.