I was reading about some Catholic Christological heresies. Then I came across Monophysitisism and Eutychianism. Both discuss the divine and human nature of Christ. They both theorize that Christ had only one nature. As opposed to adoptionism the single nature of Christ according to these doctrines is divine. Now I am a bit confused. Are these two doctrines one and the same? Or are there some subtle differences between these two doctrines?
The Wikipedia article on Monophysitisism answers your question when it says:
There are two major doctrines that can indisputably be called "monophysite":
- Eutychianism holds that the human and divine natures of Christ were fused into one new single (mono) nature: His human nature was "dissolved like a drop of honey in the sea".
- Apollinarism or Apollinarianism holds that Christ had a human body and human "living principle" but that the Divine Logos had taken the place of the nous, or "thinking principle", analogous but not identical to what might be called a mind in the present day.
In other words, Eutychianism is a subset of Monophysitisism.