Warfield on the Two Natures of Christ

Here is Warfield on the Chalcedonian definition:

"The final statement...was arrived at, externally considered, through protracted and violent controversies, during the course of which every conceivable construction of the biblical data had been exploited, weighed, and its elements of truth sifted out and preserved, while the elements of error which deformed it were burned up as chaff in the fires of the strife.

Out of the continuous controversy of a century there issued a balanced statement in which all the elements of the biblical representation were taken up and combined. Work so done is done for all time; and it is capable of ever-repeated demonstration that in the developed doctrine of the Two Natures...and in it alone, all the biblical data are brought together in a harmonious statement, in which each receives full recognition, and out of which each may derive its sympathetic exposition.

This key unlocks the treasures of the biblical instruction on the Person of Christ as none other can, and enables the reader as he currently scans the sacred pages to take up their declarations as they meet him, one after the other, into an intelligently consistent conception of his Lord."

B. B. Warfield, "Recent Christological Speculation," in The Works of Benjamin B. Warfield vol. III: Christology and Criticism, p. 264-5

And here is the Chalcedonian definition (451 AD):

Therefore, following the holy fathers, we all with one accord teach men to acknowledge one and the same Son, our Lord Jesus Christ, at once complete in Godhead and complete in manhood, truly God and truly man, consisting also of a reasonable soul and body; of one substance with the Father as regards his Godhead, and at the same time of one substance with us as regards his manhood; like us in all respects, apart from sin; as regards his Godhead, begotten of the Father before the ages, but yet as regards his manhood begotten, for us men and for our salvation, of Mary the Virgin, the God-bearer; one and the same Christ, Son, Lord, Only-begotten, recognized in two natures, without confusion, without change, without division, without separation; the distinction of natures being in no way annulled by the union, but rather the characteristics of each nature being preserved and coming together to form one person and subsistence, not as parted or separated into two persons, but one and the same Son and Only-begotten God the Word, Lord Jesus Christ; even as the prophets from earliest times spoke of him, and our Lord Jesus Christ himself taught us, and the creed of the fathers has handed down to us.