CHRISTOLOGY is that branch of theology which treats of the Person of Christ. No attempt was made in apostolic times to formulate a Christology; the early church contenting itself with testifying to the true, yet sinless humanity, the pre-existence, the divine Sonship, the resurrection, the exaltation, and the supreme authority of its Founder. It was not till speculative minds began to broach ideas inconsistent with this accepted faith that a theological representation of the church's views was found necessary. The symbolic form in which the generally accepted doctrine has been handed down to us was the result of prolonged, and not unfrequently acrimonious discussions. Prior to the Council of Nice (325 A.D.) various Christological theories were promulgated by the Ebionites, to whom belonged the Nazarenes, the Cerinthians, and the Gnostics of the pseudo-Clementine type, by the Docetæ, and by the Gnostics proper. Some of these denied the pre-existence of Christ, and attributed his peculiar greatness to a supernatural endowment conferred upon him at his baptism, while others resolved his humanity into a mere phantom, and represented his person as composed of a spiritual Æon. These parties were, however, but short-lived. More formidable were the Sabellians and the Arians. The former denied the doctrine of the immanent Trinity. To them, accordingly, the higher nature of Christ was simply absolute Deity in self-manifestation. The Arians, on the other hand, represented Jesus as the first and loftiest of God's creatures. In their view he was not, therefore, truly God. It was specially with a reference to these two opposing parties that the Council of Nice was summoned by Constantine. The results of the deliberations of this council are embodied in the well-known Nicene Creed. Both Sabellianism and Arianism were pronounced heretical, and the eternal Sonship of Christ was solemnly asserted. The question, however, remained undecided how the union between the divine and the human in his person was to be expressed. Apollinaris, Bishop of Laodicea, advanced the theory that Christ's manhood was constituted solely of an animal soul and body, while the Logos took the place of the mind, or spirit, in him. His true humanity was thus denied. Nestorians, Bishop of Constantinople, started a rival theory. While granting the true divinity and humanity of Christ, he denied their union in a single, self-conscious personality. According to him the union was only moral or sympathetic. The Nestorian theory thus involved the breaking up of the personality into a duality. Eutyches of Constantinople wrote against Nestorianism, but his zeal carried him to the other extreme. His contention was that in the incarnation the human was transmuted into the divine. He thus obliterated the humanity.
At the Council of Chalcedon (451 A.D.) all these views were condemned, and the Christological formula which is still regarded as orthodox was framed. The orthodox doctrine, briefly stated, holds that in the unity of the person of Jesus Christ there are two natures, a divine and a human, each nature being complete and entire, and that these are so intimately and indissolubly united as to constitute not a third nature, but a person. It warns us against either dividing the person or confounding the natures.
Notwithstanding the adoption of this creed, controversy was not by any means brought to an end. For more than three centuries questions of extreme subtlety continued to agitate the theological world—questions pertaining to the relation of nature to personality, and of both to will. The Monophysite, the Monothelite, and the Adoptionist controversies were concerned with these abstruse points. At the Council of Constantinople (681 A.D.) it was decided that in the one person of Christ there are two natures, two intelligences, two energies, and two wills. The condemned Monothelites were consequently persecuted, and they betook themselves to the mountains of Lebanon and Anti-Lebanon, where they continued to exist as a distinct sect under the name of Maronites. During the middle ages the church as a whole acquiesced in the decisions of the above-named councils, though individuals occasionally ventured to give expression to views more or less at variance with the creeds. In our day, Dyothelitism, or the doctrine that there are two wills in Christ, is not regarded as essential to orthodoxy. In fact it is largely denied among theologians of high repute.
At the time of the Reformation Christology once more became a subject of keen controversy. The occasion was a difference of opinion between Luther and Zwingli regarding the presence of Christ in the elements of the ordinance of the Supper. Eventually the Lutherans accepted the doctrine of the communicatio idiomatum—i.e. the communication of the properties of the divine nature of Christ to his humanity. By this doctrine they sought to establish the ubiquity of Christ's body. The Lutheran dogma was rejected by the Reformed theologians.
The next important movement in connection with Christology originated with Lælius Socinus (1525–62) and his nephew, Faustus Socinus (1539–1604). They taught that Christ was a mere man, but distinguished from all others in the following particulars: He was miraculously conceived, was sinless, was specially endowed with the Holy Spirit, was taken up to heaven prior to the commencement of his ministry, in order that he might see God and receive instructions from him, he rose from the dead and is now exalted in heaven far above all creatures, he is invested as God's viceroy with all power in heaven and in earth. In view of his exaltation they taught that Christ may justly be termed a God, in a sense different from that in which rulers are termed gods, and therefore he ought to be worshipped. Unitarians, who may be regarded as the modern representatives of the Socinians, speak of Christ as the Ideal Man, but probably none of them would accord him all the high distinctions above specified.
At the present day there is in vogue a Christological theory known as the doctrine of kenosis ('empty'), which is variously set forth by a considerable number of evangelical theologians. It derives its name from the Greek verb ekenōse which occurs in Philip. ii. 7. In its modern form the theory is probably traceable to Zinzendorf. It is advocated by such writers as Thomasius, Gess, and Godet. Its aim is to do justice to the genuine development of the Man Jesus Christ. This it seeks to accomplish by postulating an emptying of himself on the part of the Logos in the act of incarnation. He laid aside, it is said, not only his divine attributes, but even his divine self-consciousness. These he gradually regained during the course of his earthly history, and by the time that he ascended the process was complete. Such in brief is the theory. What its future may be it is vain to guess. As yet, however, the great mass of orthodox theologians look askance at it.
According to Shedd, the following four factors are necessary in order to a complete conception of Christ's Person: (1) True and proper deity; (2) true and proper humanity; (3) the union of deity and humanity in one person; (4) the distinction of deity from humanity in the one person, so that there be no mixture of natures.
The standard book on the history of Christology is Dorner's Doctrine of the Person of Christ. See also Bull's Defence of the Nicene Creed, and his Judgment of the Catholic Church, &c.; Bruce's Humiliation of Christ; Hagenbach's History of Doctrines; and the separate articles on the heresies (ARIUS, NESTORIUS, &c.).