Chalcedonian Definition
From ReformedWiki.org, the wiki for Reformed Christianity
The Chalcedonian Definition, also known as Chalcedonianism or Dyophysitism, was the Christological definition formulated in the 4th century at the ecumenical Council of Chalcedon. It rejected Miaphysitism, or the idea that Jesus is of one nature, which is both human and divine; Monophysitism, or the idea that Jesus is of one nature, which is fully divine; and Nestorianism, or the idea that the nature of Jesus is fully human, and that the nature of Christ is divine, thus separating Jesus Christ. This was to espouse Dyophysitism, or the idea that Jesus is of two natures, one human and one divine.
