35. These among many other examples refer to the mixing of rite, which is forbidden by the Church's laws. But there is no forbidden mixing of rites involved if, for a lawful cause, priests of the Oriental rite are allowed to celebrate Mass and other services in a Latin church and administer the sacraments to their own people. We see this happening openly in Rome where our churches are available to Armenian, Coptic, Melchite, and Greek priests for the celebration of Mass to satisfy their piety, even though they have their own churches where they could offer the sacrifice of the Mass. They have only to bring with them the vestments and other necessities for celebrating Mass according to their rite, as well as a server from their own people; they must also take appropriate steps with guards and prefects of the sanctuary to prevent riotous tumults among the bystanders on account of the novelty of the event. These matters are fully discussed in the edict promulgated at Our command on February 13, 1743, by Our Vicar General in the City and its district, Giovanni Antonio Guadagni, who then was titular priest of Sts. Sylvester and Martin on the Mountains and is now Bishop of Tusculum and Cardinal.

Important for this topic is the following event: about the middle of the fifteenth century, as is well known, Mahomet II began to attack Constantinople. Some of the Greeks who had rejected the errors of the Schismatics and preserved union with the Latin Church retreated to Venice and remained there. When the Greek Cardinal Isidore came there, he informed the Senate of the Pope's wishes to have a church assigned to these people of the Greek rite for their services. The piety of the Senate was aroused, and they gave the refugees the Church of St. Blasius. In one chapel of this church for many years the Greeks performed the divine services in the Greek rite, while in the other chapels, the Latins worshipped in the Latin rite. This is attested by the renowned Flaminius Cornelius Scriptor, Venetarum Ecclesiarum, Decad. 14, p. 359: "So the services of both rites were celebrated for several years in different chapels of the same church." This practice continued until the Greeks' numbers rose and another church in addition to the Church of St. Blasius was allotted to them for their own private use.