The DefinitionThe Definition of Chalcedon

Following, then, the holy Fathers, we all with one voice teach that it should be confessed that our Lord Jesus Christ is one and the same Son, the Same perfect in Godhead, the Same perfect in manhood, truly God and truly man, the Same consisting of a rational soul and body; consubstantial with the Father as to his Godhead, and the Same consubstantial with us as to his manhood; in all things like unto us, sin only excepted; begotten of the Father before the ages as to his Godhead, and in the last days, the Same, for us and for our salvation, of the Virgin Mary, Mother of God, as to his manhood.

One and the Same Christ, Son, Lord, Only-begotten, made known in two natures which exist without confusion, without change, without division, without separation; the difference in the two natures being in no wise taken away by reason of the union, but rather the properties of each being preserved, and both concurring into one Person and one hypostasis, not parted or divided into two Persons, but one and the same Son, Only-begotten, the divine Word, the Lord Jesus Christ; even as the prophets of old have spoken concerning him, and as the Lord Jesus Christ himself has taught us and the Creed of our fathers has handed down.