Literal Interpretations of the Scriptures
I was reading "The Intellectual Origins of the European Reformation" which Dr. Tighe graciously supplied to me. The book is really good, but I want to focus for a moment on one particular aspect of the book. It is the different ways the Reformed and Lutherans approached Scripture in a literal way.
For the early Reformed, the literal sense was, more or less, the bare words themselves. But the words themselves carried a deeper spiritual meaning. So, for instance, the account of the Lord's Supper is first and foremost a description of the events of the Lord's Supper, and this account tells of the spiritual truth of what Jesus was accomplishing there--our salvation, forgiveness of sins etc.
For Luther, after he more or less abandoned the fourfold interpretation of Scripture, he settled on the moral interpretation of Scripture as the "literal" sense. By this he meant that when Scripture is describing what God does the literal sense is what God is doing "for me". Thus, when we read the account of the Last Supper, it is an account of what Jesus is doing for me. He is giving me his body and blood for the forgiveness of sins.
I think these differences, while subtle, explain why the two traditions' interpretation of the Lord's Supper differ so much. For the early Reformed (Calvin had his own system which to me seems unrelated to Zwingli or Luther) the spiritual truth behind the Lord's Supper is almost precisely what e.g. Baptists argue today. The bare words of Christ--"This is my body" don't point to the bread being his body but to the deeper spiritual truth behind "this is my body". By way of contrast, for Lutherans unless "this is my body" means it is his body, it becomes more difficult to to show what Christ is doing "for me", because the "for me" happens later on the cross and not by the sharing of his body and blood.
I think we see this elsewhere, too. For TULIP Calvinists, when the Scriptures say that God wants the world to be saved he reads it as God's elect. Not because of some devilish desire to twist the Scriptures (though I think their interpretation is wrong), but because the bare words point to a deeper spiritual truth behind themselves. The words "save the world world" point to God's plan of salvation.
A Lutheran, however, will reason that since he is part of the world the words are meant for him, or "for me" if you will.
I have not worked this systematically, but I have been thinking about it and it seems workable so far. Not as an iron rule, but as a way to understand why the Reformed come to the conclusions they come to.