36. This incident concerns Greeks who were allowed to celebrate their services in Latin Churches. But to show more clearly that this does not entail the mixing of rites forbidden by the Church, it will be appropriate to mention also Latins who for a just reason were permitted to offer the sacrifice of the Mass and perform divine services in Greek churches. This will not only confirm the opinion We have presented, but will help much to show the necessity of unanimity and benevolence among Catholics of different rites.

In White Russia, Ruthenian Catholics, who are known as United, have many churches while the Latins have few; these are far distant from the districts of the Latins who live among the Ruthenians. Sometimes the Latins are deprived of Mass for a long period because their business prevents them from travelling as far as the nearest Latin church. Latin priests could not easily travel to the few Latin churches there to celebrate Mass since those churches were so far from their own place of residence. So to avoid depriving the Latins for long periods of Mass celebrated in the Latin rite, there was only one solution: for Latin priests to celebrate the Mass in the Latin rite for the welfare of the Latins in the Ruthenian churches. At this point a difficulty was recognized in that Greek altars have no holy stone, since they offer Mass on the antimensia, that is, linens consecrated by the bishop with relics of the saints at the corners. For this reason Latin priests were obliged to bring the holy stone with them at great inconvenience, and risk breaking it in the course of the journey. But at last a timely remedy was discovered and applied to all these inconveniences by God's help. With the agreement of the Ruthenians, Latin priests were allowed to celebrate Mass in the Latin rite in the Ruthenian churches, and on the antimensia. This was approved more readily because Ruthenian priests who sometimes came to say Mass in Latin churches consecrated the sacrifice on our altar stones. This matter is treated in full in Our constitution 43, Imposito nobis (Bullarii nostri, vol. 3).