Theologically, the Assyrian Church of the East does not accept doctrinal definitions that were adopted at the Council of Ephesus (431) and the Council of Chalcedon (451), and still adheres to the Church of the East's traditional Christology, that is often labeled as Nestorian. The use and exact meaning of that term has been the subject of many debates, not only throughout history but also in modern times, since the Assyrian Church of the East has distinctive views on several christological questions and claims that its theological doctrines and traditions are essentially orthodox, while admitting the need for further inter-Christian dialog that would resolve various questions in the field of comparative christological terminology. Unlike most other churches that trace their origins to antiquity, the modern Assyrian Church of the East is not in communion with any other church.