Those present at the Council of Chalcedon accepted
Trinitarianism and the concept of
hypostatic union, and rejected
Arianism,
Modalism, and
Ebionism as
heresies (which had also been rejected at the
First Council of Nicaea in AD 325). Those present at the council also rejected the Christological doctrines of the
Nestorians,
Eutychians, and
Monophysites. The Chalcedonian doctrine of the
Hypostatic Union states that Jesus Christ has two natures, divine and human, possessing a complete human nature while remaining one divine
hypostasis. It asserts that the natures are unmixed and unconfused, with the human nature of Christ being assumed at the incarnation without any change to the divine nature. It also states that while Jesus Christ has assumed a true human nature, body and soul, which shall remain hypostatically united to his divine nature for all of eternity, he is nevertheless not a human person, as human personhood would imply a second created hypostasis existing within Jesus Christ and violating the unity of the God-man. The Hypostatic Union was also viewed as
one nature in
Roman Christianity by a minority around this time. Single-nature ideas such as
Apollinarism and
Eutychianism were taught to explain some of the seeming contradictions in Chalcedonian Christianity. ==References==