The object of calling the council was to inquire into the opinions of Nestorius, bishop of Constantinople. It would have been well for it if it had enjoyed the benefit of the great and good Augustine's presence; for its proceedings were carried on in such a way that it is not pleasant to read of them But, whatever may have been the faults of those who were active in the council it laid down clearly the truth which Nestorius was charged with denying -- that (as is said in the Athanasian creed) our blessed Lord, "although He be God and man, yet is He not two, but one Christ;" and this council which was held at Ephesus in the year 431, is reckoned as the third general council.
Some years after it, a disturbance arose about a monk of Constantinople, named Eutyches, who had been very zealous against Nestorius, and now ran into errors of an opposite kind. Another council was held at Ephesus in 449; but Dioscorus, bishop of Alexandria, and a number of disorderly monks who were favourable to Eutyches, behaved in such a furious manner at this assembly, that, instead of being considered as a general council, it is known by the name "Latrocinium," which means a meeting of robbers. But two years later, when a new emperor had succeeded to the government of the East, another general council was held at Chalcedon (pronounced kal-SEE-don) (AD 451); and there the doctrines of Eutyches were condemned, and Dioscotus was deprived of his bishopric. This council, which was the fourth of the general councils, was attended by six hundred and thirty bishops. It laid down the doctrine that our Lord is "One, not by conversion [or turning] of the Godhead into flesh, but by taking of the manhood into God: One altogether, not by confusion of substance, but by unity of person; for, as the reasonable soul and flesh is one man, so God and man is one Christ."
According, then, to these two councils, which were held against Nestorius and Eutyches, we are to believe that our blessed Lord is really God and really man. The Godhead and the manhood are not mixed together in Him, so as to make something which would be neither the one nor the other (which is what the creed means by "confusion of substance"); but they are in Him distinct from each other, just as the soul and the body are distinct in man, and yet they are not two persons, but are joined together in one Person, just as the soul and the body are joined in one man. All this may perhaps be rather hard for young readers to understand, but the third and fourth general councils are too important to be passed over, even in a little book like this; and, even if what has been said here should not be quite understood, it will at least show that all those distinctions in the Athanasian creed mean something, and that they were not set forth without some reason, but in order to meet errors which had actually been taught.
I may mention here two other things which were settled by the Council of Chalcedon -- that it gave the bishops of Constantinople authority over Thrace, Asia, and Pontus; and that it raised Jerusalem, which until then had been only an ordinary bishopric, to have authority of the same kind over the Holy Land. These chief bishops are now called "patriarchs", and there were thus five patriarchs -- namely, the bishops of Rome, Constantinople, Alexandria, Antioch, and Jerusalem. The map will show you how these patriarchates were divided, but there were still some Christian countries which did not belong to any of them.
Having thus mentioned the title of patriarchs, I may explain here the use of another title which we hear much oftener -- I mean the title of "pope". The proper meaning of it is "father"; in short, it is nothing else than the word "papa," which children among ourselves use in speaking to their fathers. This title of pope (or father), then, was at first given to all bishops; but, by degrees, it came to be confined in its use; so that, in the East, only the bishops of Rome and Alexandria were called by it, while in the West it was given to the bishop or patriarch of Rome alone.