Over at John Sanidopoulos’s Mystagogy website, we read the following regarding the Fourth Ecumenical Council, a quotation from the late Fr. John Romanides:
Theologians of the Vatican have been supporting their position that Leo of Rome and his Tome became the basis of the decisions of the Fourth Ecumenical Council of 451 which, according to them, supposedly corrected the monophysitic and theopassion tendencies of Cyril of Alexandria. But the reality of the matter was that some 50 bishops refused to sign Leo’s Tome claiming that it did not agree with the Synodical Letters of Cyril against Nestorius which were the basis of the decision of the Third Ecumenical Council in 381 [sic, should be 431 -O&H ed.]. They were given five days to examine the Tome of Leo with the said letters of Cyril. They all agreed that Leo indeed agrees with Cyril. Their statements to this effect are individually recorded in the minutes.
How one sees the Council of Chalcedon (AD 451) is a major tessera in the mosaic of the history of Church polity. If St. Leo’s Tome were simply accepted as an infallible pronouncement from the papacy at Chalcedon, then of course there would have been no need for debate by the assembled fathers. But debate there was, and Leo was ultimately judged by the theology of St. Cyril of Alexandra, the hero of the Third Ecumenical Council at Ephesus.