what has the Church taught consistently for the past 2,000 years on the subject of the Real Presence?
I don't debate much regarding the Real Presence, b/c as an Orthodox Christian it's more about faith and reason and that we don't attempt to reconcile the two...
Following the Holy Fathers, Orthodoxy uses science and philosophy to defend and explain her Faith. Unlike Roman Catholicism, Orthodoxy does not build on the results of philosophy and science. The Church does not seek to reconcile faith and reason. Orthodoxy makes no effort to prove by logic or science what Christ gave His followers to believe. If physics, biology, chemistry or philosophy lends support to the teachings of the Church, the Church does not refuse them. However, Orthodoxy is not intimidated by man's intellectual accomplishments. The Church does not bow to them and change the Christian Faith to make it consistent with the results of human thought and science.
St. Basil the Great advised young monks to use Greek philosophy as a bee uses the flower. Take only the "honey," ---- the truth --- which God has planted in the world to prepare men for the Coming of the Lord.
For example, the Greeks had a doctrine of the Logos. The Gospel of John opens, "In the beginning was the Word (Logos, in Greek)". For the pagans, the Logos was not God, as He is for Christians; rather he is a principle, a power or force by which "God: formed and governs the world." The Fathers pointed to the similarity between the Logos or Word of the Bible and the Logos of Greek philosophy as a sign of Providence. The difference between them, they attributed to the sinfulness of men and the weakness of the human intellect. They remembered the words of the Apostle Paul, "Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Christ" (Col. 2: 8).
Roman Catholicism, on the other hand, places a high value on human reason. Its history shows the consequence of that trust. For example, in the Latin Middle Ages, the 13th century, the theologian-philosopher, Thomas Aquinas, joined "Christianity" with the philosophy of Aristotle. From that period til now, the Latins have never wavered in their respect for human wisdom; and it has radically altered the theology, mysteries and institutions of the Christian religion.