Editing Pope Leo I (section)

===Council of Chalcedon===
{{Main|Council of Chalcedon}}
[[Eutyches]], in the beginning of the conflict, appealed to Leo and took refuge with him on his condemnation by [[Archbishop Flavian of Constantinople|Flavian]], but on receiving full information from Flavian, Leo took his side decisively. Leo demanded of the emperor that an [[ecumenical]] council should be held in Italy, and in the meantime, at a Roman synod in October 449, repudiated all the decisions of the "[[Robber Synod]]". In his letters to the emperor and others he demanded the deposition of Eutyches as a [[Manichaean]] and [[Docetic]] heretic.

The [[Council of Chalcedon]] of 451 rejected the heresy of Eutyches who denied the true human nature of the Son of God, and affirmed the union in his one Person, without confusion and without separation, of his two natures, human and divine.

The acts of the council report: <blockquote>"After the reading of the foregoing epistle, the most reverend bishops cried out: This is the faith of the fathers, this is the faith of the Apostles. So we all believe, thus the orthodox believe. Anathema to him who does not thus believe. Peter has spoken thus through Leo. So taught the Apostles. Piously and truly did Leo teach, so taught Cyril. Everlasting be the memory of Cyril. Leo and Cyril taught the same thing, anathema to him who does not so believe. This is the true faith. Those of us who are orthodox thus believe. This is the faith of the fathers. Why were not these things read at Ephesus? These are the things [[Pope Dioscorus I of Alexandria|Dioscorus]] hid away."<ref name=Acts>{{Cite web |url=http://www.fordham.edu/halsall/basis/chalcedon.html |title=Acts of the Council, Session II (continued) |access-date=2011-06-09 |archive-date=2013-11-04 |archive-url=https://web.archive.org/web/20131104164621/http://www.fordham.edu/halsall/basis/chalcedon.html |url-status=dead }}</ref><ref name="Evans 2004 p. 246">{{cite book | last=Evans | first=G.R. | title=First Christian Theologians | publisher=Wiley | series=The Great Theologians | year=2004 | isbn=978-0-631-23188-2 | url=https://books.google.com/books?id=y3UvKwvmzEIC&pg=PA246 | page=246}}</ref><ref>{{Cite web |url=http://www.ccel.org/ccel/schaff/npnf214.xi.viii.html |title=Extract from the Acts of the Council |access-date=2008-10-10 |archive-url=https://web.archive.org/web/20130928083148/http://www.ccel.org/ccel/schaff/npnf214.xi.viii.html |archive-date=2013-09-28 |url-status=dead }}</ref></blockquote>

Leo firmly declined to confirm their disciplinary arrangements, which seemed to allow Constantinople a practically equal authority with Rome and regarded the civil importance of a city as a determining factor in its ecclesiastical position; but he strongly supported its dogmatic decrees, especially when, after the accession of Emperor [[Leo I (emperor)|Leo I]] (457), there seemed to be a disposition toward compromise with the Eutychians.{{citation needed|date=August 2019}}