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Watson's Biblical & Theological Dictionary [1]

a denomination which arose in the fifth century, from Nestorius, bishop of Constantinople; a man of considerable learning and eloquence, and of an independent spirit. The Catholic clergy were fond of calling the Virgin Mary "Mother of God," to which Nestorius objected, as implying that she was mother of the divine nature, which he very properly denied; and this raised against him, from Cyril and others, the cry of heresy, and perhaps led him into some improper forms of expression and explication. It is generally agreed, however, by the moderns, that Nestorius showed a much better spirit in controversy than his antagonist, St. Cyril.

As to the doctrine of the trinity, it does not appear that Nestorius differed from his antagonists, admitting the coequality of the divine Persons; but he was charged with maintaining two distinct persons, as well as natures, in the mysterious character of Christ. This, however, he solemnly and constantly denied; and from this, as a foul reproach, he has been cleared by the moderns, and particularly by Martin Luther, who lays the whole blame of this controversy on the turbulent and angry Cyril. ( See Hypostatical Union . ) The discordancy not only between the Nestorians and other Christians, but also among themselves, arose, no doubt, in a great measure, from the ambiguity of the Greek terms hypostasis and prosopon. The councils assembled at Seleucia on this occasion decreed that in Christ there were two h y postases. But this word, unhappily, was used both for person and subsistence, or existence; hence the difficulty and ambiguity: and of these hypostases it is said the one was divine, and the other human;—the divine Word, and the man Jesus. Now of these two hypostases it is added, they had only one barsopa, the original term used by Nestorius, and usually translated by the Greeks, "person;" but to avoid the appearance of an express contradiction, Dr. Mosheim translates this barbarous word "aspect," as meaning a union of will and affection, rather than of nature or of person. And thus the Nestorians are charged with rejecting the union of two natures in one person, from their peculiar manner of expressing themselves, though they absolutely denied the charge.

In the earliest ages of Nestorianism, the various branches of that numerous and powerful sect were under the spiritual jurisdiction of the Catholic patriarch of Babylon,—a vague appellation which has been successively applied to the sees of Seleucia, Ctesiphon, and Bagdad,—but who now resides at Mousul. In the sixteenth century the Nestorians were divided into two sects; for in 1551 a warm dispute arose among them about the creation of a new patriarch, Simeon Barmamas, or Barmana, being proposed by one party, and Sulaka, otherwise named Siud, earnestly desired by the other; when the latter, to support his pretensions the more effectually, repaired to Rome, and was consecrated patriarch in 1553, by Pope Julius III, whose jurisdiction he had acknowledged, and to whose commands he had promised unlimited submission and obedience. Upon this new Chaldean patriarch's return to his own country, Julius sent with him several persons skilled in the Syriac language, to assist him in establishing and extending the papal empire among the Nestorians; and from that time, that unhappy people have been divided into two factions, and have often been involved in the greatest dangers and difficulties, by the jarring sentiments and perpetual quarrels of their patriarchs. In 1555, Simeon Denha, archbishop of Gelu, adopted the party of the fugitive patriarch, who had embraced the communion of the Latin church; and, being afterward chosen patriarch himself, he fixed his residence in the city of Van, or Ormia, in the mountainous parts of Persia, where his successors still continue, and are all distinguished by the name of Simeon; but they seem of late to have withdrawn themselves from their communion with the church of Rome. The great Nestorian pontiffs who form the opposite party, and who have, since 1559, been distinguished by the general denomination of Elias, and reside constantly at Mousul, look with a hostile eye on this little patriarch; but since 1617 the bishops of Ormus have been in so low and declining a state, both in opulence and credit, that they are no longer in a condition to excite the envy of their brethren at Mousul, whose spiritual dominion is very extensive, taking in great part of Asia, and comprehending within its circuit the Arabian Nestorians, as also the Christians of St. Thomas, who dwell along the coast of Malabar.

Charles Buck Theological Dictionary [2]

The followers of Nestorius, the bishop of Constantinople, who lived in the fifth century. They believed that in Christ there were not only two natures, but two persons; of which the one was divine, even the eternal word; and the other, which was human, was the man Jesus: that these two persons had only one aspect: that the union between the Son of God and the son of man was formed in the moment of the virgin's conception, and was never to be dissolved: that it was not, however, an union of nature or of person, but only of will and affection. (Nestorius, however, it is said, denied the last position:) that Christ was therefore to be carefully distinguished from God, who dwelt in him as in his temple; and that Mary was to be called the mother of Christ, and not the mother of God. One of the chief promoters of the Nestorian cause was Barsumas, created bishop of Nisibis, A. D. 435. Such was his zeal and success, that the Nestorians who still remain in Chaldea, Persia, Assyria, and the adjacent countries, consider him alone as their parent and founder. By him Pherozes, the Persian monarch, was persuaded to expel those Christians who adopted the opinions of the Greeks, and to admit the Nestorians in their place, putting them in possession of the principal seat of ecclesiastical authority in Persia, the see of Selucia, which the patriarch of the Nestorians had always filled even down to our time. Barsumas also erected a school at Nisibis, from which proceeded those Nestorian doctors who in the fifth and sixth centuries spread abroad their tenets through Egypt, Syria, Arabia, India, Tartary, and China. In the tenth century, the Nestorians in Chaldea, whence they are sometimes called Chaldeans, extended their spiritual conquests beyond Mount Imaus, and introduced the Christian religion into Tartary properly so called, and especially into that country called Karit, bordering on the northern part of China.

The prince of that country, whom the Nestorians converted to the Christian faith, assumed, according to the vulgar tradition, the name of John after his baptism, to which he added the surname of Presbyter, from a principle of modesty; whence, it is said, his successors were each of them called Prester John until the time of Gengis Khan. But Mosheim observes, that the famous Prester John did not begin to reign in that part of Asia before the conclusion of the eleventh century. The Nestorians formed so considerable a body of Christians, that the missionaries of Rome were industrious in their endeavours to reduce them under the papal yoke. Innocent IV. in 1246, and Nicholas IV. in 1278, used their utmost efforts for this purpose, but without success. Till the time of pope Julius III. the Nestorians acknowledged but one patriarch, who resided first at Bagdad, and afterwards at Mousul; but a division arising among them, in 1551 the patriarchate became divided, at least for a time, and a new patriarch was consecrated by that pope, whose successors fixed their residence in the city of Ormus, in the mountainous parts of Persia, where they still continue, distinguished by the name of Simeon; and so far down as the seventeenth century, these patriarchs persevered in their communion with the church of Rome, but seem at present to have withdrawn themselves from it.

The great Nestorian pontiffs, who form the opposite party, and look with a hostile eye on this little patriarch, have, since the year 1559, been distinguished by the general denomination of Elias, and reside constantly in the city of Mousul. Their spiritual dominion is very extensive, takes in a great part of Asia, and comprehends also within its circuit the Arabian Nestorians, and also the Christians of St. Thomas, who dwell along the coast of Malabar. It is observed, to the lasting honour of the Nestorians, that of all the Christian societies established in the East, they have been the most careful and successful in avoiding a multitude of superstitious opinions and practices that have infected the Greek and Latin churches. About the middle of the seventeenth century, the Romish missionaries gained over to their communion a small number of Nestorians, whom they formed into a congregation or church; the patriarchs or bishops of which reside in the city of Amida, or Diarbeker, and all assume the denomination of Joseph. Nevertheless, the Nestorians in general persevere to our own times in their refusal to enter into the communion of the Romish church, notwithstanding the earnest entreaties and alluring offers that have been made by the pope's legate to conquer their inflexible constancy.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [3]

Bibliography Information McClintock, John. Strong, James. Entry for 'Nestorians'. Cyclopedia of Biblical, Theological and Ecclesiastical Literature. Harper & Brothers. New York. 1870.