Origen. Early Christianity, Church Fathers, Catechetical School of Alexandria, Clement of Alexandria, Patriarch of Alexandria, Caesarea Maritima, Septuagint, Christian theology, Neopythagoreanism, Neoplatonism, Logos (Christianity), Trinity, Anathema, Eusebius of Caesarea, Hexapla, Church History (Eusebius), Philokalia, Second Council of Constantinople