Ephrem the Syrian
The Chaldean Catholic Church honours as doctor Polycarp, Eustathius of Antioch, Meletius, Alexander of Jerusalem, Athanasius, Basil, Cyril of Alexandria, Gregory Nazianzus, Gregory of Nyssa, John Chrysostom, Fravitta of Constantinople, Ephrem the Syrian, Jacob of Nisibis, Jacob of Serugh, Isaac of Armenia, Isaac of Nineveh, and Maruthas of Martyropolis.