The Eastern Orthodox Doctrine of the Immaculate Conception, Part 1

"The All[-]Holiness of Mary, or Immaculate Conception, as it was sometimes called even in the East and now commonly called in the Latin West, was primarily linked in the East, not to the redemption, but to what we know as the absolute primacy of Christ for the sake of whom the entire creation and then the work of redemption were undertaken. The notion of perfect redemption by a perfect redeemer, as St. Maximilian Kolbe notes, depends on that of the absolute primacy of Christ; and the Immaculate Conception is the Marian mode of that primacy, for us the sign of its actuality. ... 

"Fr. Kappes's study ... is rather a detailed analysis of one particular title of Mary: Prepurified, common in the East from the earliest times, a synonym for Immaculate Conception. ... In the West, however, it initially [ab origine lol] appeared to mean just the opposite, viz., one gradually purified from sin after conception, not preserved. So it was understood by St. Thomas and Scotus in their reading of the Damascene and thereafter among Latins until the time of Gregory Palamas (1296-1359) and Mark Eugenicus (1392-1447) when the disciples of Scotus first began to realize, not only that the real meaning of the title, far from supporting maculism ([the] position of St. Thomas), but that it supported just the opposite: immaculatism ([the] position of Scotus) and had a strong biblical basis in the account of the purification-presentation of Mary and Jesus in the Temple (cf. Lk 2: 22-40). Once the interpretation of the Damascene was corrected and the antiquity of the title in Scripture and tradition was recognized, the basis for this doctrine in the deposit of faith became clearly evident to those supporting the views of Duns Scotus. ... [T]he mystery of Mary's person is our key — to both the study of theology and of the economy of salvation — one pointing to crucial features of a Christian metaphysics as Marian."

-- Fr. Peter M. Fehlner, FI, "Preface"to Fr. Christiaan W. Kappes, The Immaculate Conception: The Immaculate Conception: Why Thomas Aquinas Denied, While John Duns Scotus, Gregory Palamas, & Mark Eugenicus Professed the Absolute Immaculate Existence of Mary (New Bedford, MA: Academy of the Immaculate, 2014), pp. xvi-xvii.