Jesuit Writes On Interaction With Seperated Christian

Communicatio in Sacris

An Historical Study of the Problem of Liturgical Services in Common with Eastern Christians Separated from Rome

By Fr. Wilhelm de Vries, S.J. (German Jesuit)

An excerpt.

Propaganda clearly expressed the basic reason for the rejection of common liturgical services in a letter to Andreas Akhigan, the Syrian- Catholic Archbishop of Aleppo. The letter forbade "every positive act of participation in the rites of the heretics", because such an act would signify "the approval of their errors and of their sacrifice",

The recognition, that is, of the legitimacy of their worship. Such acts would be the burial of heretics or the blessing of incense in their churches.

Andreas was bishop of the entire "Syrian nation" in Aleppo, including the non-Catholics. He found himself in an awkward situation. He could hardly avoid participation in the liturgical ceremonies of the nonCatholic priests under him. Nonetheless, Rome insisted on the prohibition.
Link to an extremely interesting article (here) at a blog called A Roman's Archives.

The great East / West Jesuit college, Pontifical Oriental Institute
Picture is of the Hagia Sophia