Modern critics of his work note that he made no attempt to understand the oriental religions which he attacked, and censure him for invoking the aid of the Inquisition and sanctioning persecution of the Nestorians in Malabar.
When, in the 5th century A.D., owing to theological differences the Syriac-using Christians became divided into Nestorians or East Syrians and Jacobites (Monophysites) or West Syrians, certain differences of pronunciation, chiefly in the vowels, began to develop themselves.
The biruna of the Chaldaean Nestorians, on the other hand, worn by all bishops, is a sort of hood ornamented with a cross.
Modern missions have made no great conquests there, and in earlier times the Nestorians and Jacobites who penetrated to central Asia, China and India, received respectful hearing, but never had anything like the success which attended Buddhism and Islam.
The proportion borne to one another by the different religions, as estimated in 1910, is: 50% Mussulman, 41% Orthodox, 6% Catholic, 3% all others (Jews, Druses, Nestorians, &c.).