Question 153:
After the conflict of 1054, Catholics and Orthodox are said to have excommunicated each other. Have these verdicts since been revoked so that Catholics and Orthodox can pray and celebrate Holy Mass together?
Answer: The act of excommunication of 1054 CE did not affect the whole of the Orthodox and Catholic faiths, but only the individual people involved. Nevertheless, there had been serious implications for the relationship between Catholics and Orthodox. On 7. December 1965, therefore, two simultaneous acts in Rome and in the Phanar, the official seat of the Ecumenical Patriarch, took place in order together to ‘regret’ in the spirit of repentance the events of 1054 and to eradicate them from the memory of the Church.
Since then Catholics and Orthodox have been able to share liturgical prayer. However, the Orthodox will generally not permit Catholics to receive Holy Communion in Orthodox liturgy. According to can. 844, section 3 of the CIC (=Codex Iuris Canonici], a Catholic priest may give Communion to Orthodox Christians, if they request it of their own accord, and if they are appropriately disposed (Dr. Theresia Hainthaler).