The Third Council of Constantinople
The Third Council of Constantinople, which became the Sixth Ecumenical Council was summoned by the emperor Constantine IV in 678AD and closed in 681AD. This council, picking up where the Definition of Chalcedon left off, addressed whether the two natures of Christ (human and divine) also had two separate wills. The council concluded that Jesus has two wills as well as two natures, and that those two wills did not conflict with or strive against each other.
The Council of Nicaea 325AD previously defined Jesus being fully divine and fully human. It did did not; however, state how Christ could be both divine and human, or how the divine and human were related within His person. This led to the Christological controversies of the fourth and fifth centuries which the Council of Chalcedon attempted to address. To summarize, the produced doctrine stated that two natures, one human and one divine, are united in the one person of Christ. The Council further stated that each of these natures, the human and the divine, was distinct and complete.
The western churches readily accepted the creed, but some eastern churches still held to the Alexandrian formula of the oneness of Christ’s nature as the incarnation of God the Word (that is, His Divinity and Humanity are united in one nature).
Statement of Faith (681AD)
We also proclaim two natural willings or wills in him and two natural operations, without separation, without change, without partition, without confusion, according to the teaching of the holy Fathers -- and two natural wills not contrary to each other, God forbid, as the impious heretics have said they would be, but his human will following, and not resisting or opposing, but rather subject to his divine and all-powerful will. For it was proper for the will of the flesh to be moved naturally, yet to be subject to the divine will, according to the all-wise Athanasius. For as his flesh is called and is the flesh of God the Word, so also the natural will of his flesh is called and is God the Word’s own will, as he himself says: "I came down from heaven, not to do my own will, but the will of the Father who sent me," calling the will of the flesh his own, as also the flesh had become his own. For in the same manner that his all-holy and spotless ensouled flesh, though divinized, was not destroyed, but remained in its own law and principle also his human will, divinized, was not destroyed, but rather preserved, as Gregory the divine says: "His will, as conceived of in his character as the Saviour, is not contrary to God, being wholly divinized."
We also glorify two natural operations in the same our Lord Jesus Christ, our true God, without separation, without change, without partition, without confusion, that is, a divine operation and a human operation, as the divine preacher Leo most clearly says: "For each form does what is proper to it, in communion with the other; the Word, that is, performing what belongs to the Word, and the flesh carrying out what belongs to the flesh." We will not therefore grant the existence of one natural operation of God and the creature, lest we should either raise up into the divine nature what is created, or bring down the preeminence of the divine nature into the place suitable for things that are made. For we recognize the wonders and the sufferings as of one and the same person], according to the difference of the natures of which he is and in which he has his being, as the eloquent Cyril said.
Preserving therefore in every way the unconfused and undivided, we set forth the whole confession in brief; believing our Lord Jesus Christ, our true God, to be one of the holy Trinity even after the taking of flesh, we declare that his two natures shine forth in his one hypostasis, in which he displayed both the wonders and the sufferings through the whole course of his dispensation, not in phantasm but truly, the difference of nature being recognized in the same one hypostasis by the fact that each nature wills and works what is proper to it, in communion with the other. On this principle we glorify two natural wills and operations combining with each other for the salvation of the human race.