LATERAN COUNCIL IV 1215
Ecumenical XII (against the Albigensians, Joachim, Waldensians etc.)
The Trinity, Sacraments, Canonical Mission, etc.*
Chap. 4. The Pride of the Greeks Against the Latins *
435 Although we wish to cherish and honor the Greeks who in our days are returning to the obedience of the Apostolic See, by sustaining their customs and rites in as far as we are able with the Lord, yet we do not wish nor are we able to defer to them in these things which engender danger to souls and which detract from ecclesiastical honor. For when the church of the Greeks with certain accomplices and their protectors withdrew itself from the obedience of the Apostolic See, the Greeks began to detest the Latins so much that among other things which they impiously committed to their dishonor, if at any time Latin priests celebrated Mass on their altars, they themselves were unwilling to sacrifice on these (altars), before they washed them, as if defiled on account of this (sacrifice by the Latin priests); these same Greeks presumed with indiscreet boldness to rebaptize those baptized by the Latins, and up to this time, as we have learned, certain ones do not fear to do this. Therefore, wishing to remove such scandal from the Church, on the recommendation of the Sacred Council, we strictly command that they do not presume such things in the future, conforming themselves as obedient sons to the holy Roman Church, their mother, so that there may be “one flock and one shepherd” [John 10:16]. If anyone, however, shall presume any such thing, struck by the sword of excommunication, let him be deposed from every office and ecclesiastical favor.