In cases like this, sometimes overformulation (Such as the Nicene or Cappadocian view) does create a somewhat different concept, which people try to read back into the Apostles. Everyone, including Protestants, seems to believe the entire Church held an expression of the Godhead identical to Niceno-Chalcedon, and look for "hints" of it in the Bible, which are taken to prove the Apostles would recognize the later formula.But it was significantly less developed than that. It is a far different thing to express God as "Father", who reveals Himself as Son and Holy Spirit, as the pre-Nicene fathers did, than it is to make the Father, an equal "third member" of some "Godhead" (which you can really appy the same criticism they leveled at the modalists, of that constituting a fourth person, distinct from the third, and confuses others such as Muhammad who criticized it for making God "a third of three").
So with the Communion, we had the same problem. The later Church taking a biblical statement, and overformulating it, and reading it back to the NT.
Also of special note, is that a person on your side, Matt, in one of the RCC threads, acknowledged:
Actually, much as it pains me to disagree with you, that's not quite correct: both Eusebius of Caesarea and Evagrius Ponticus (sp?) expounded what we would today call 'mere memorialism' in the 4th century IIRC and St Augustine initially adopted a symbolic approach to the Eucharist.
OF course, this is followed by a disclaimer that "neither of the former two can be ranked as ECFs and both went against the overwhelming 'realist' consensus of the Church at that time".
Of course, none of the rest of the consensus" of that time can qulaify as "ECF"s either, though they are often used in trying to prove that "the ECF's passed down the doctrine handed to them by the Apostles". But of the true ECF's, the earliest merely reiterated the words of Christ or Paul, and added no interpretation or implication to it. the later ECF's, then began adding a "change" in the elements effected by the prayer. Then, the doctrine continues to develop from there.
So the whole notion that Zwingli made his "memorial" concept up out of nowhere, and against a solid "1500 year universal consensus" should be laid to rest. Even if it was just those three people, that right there is three big holes in your grandiose "Zwingli vs. 1500 year consensus" claim. The "realist" position became the most popular (as did the Nicene formula, and as did the Papacy, persecution of heretics, etc), but it was neither handed down from the apostles, not absolutely agreed on. There were voices of dissent, that were silenced by the Church with its "majority rules" politics.
It depends on what exactly we mean by "mystical". Those are truths we cannot completely explain, but I believe, again, that the problem has been exacerbated by overformulation. We try to explain more, and then have to explain the explanations, and then after a mountain of philosophization, we then finally conclude "It's above our comprehansion". That's what I mean by "mystical", and I do not see those three truths as really "mystical" in quite that sense. But gnostic religion was definitely more like that, and that's where the "gnosis" comes in.