ABSTRACT
Bogomils and Cathars were, according to the prevailing theory, “Gnostic dualist heresies” of the Middle Ages. They were Gnostic, because both the Bogomils and the Cathars believed that only the initiated were given the secret knowledge of cosmogony and anthropogony that alone could bring salvation. They were dualist, because they believed in two fundamental cosmic principles, whether they were absolute and from eternity as two gods, or, in a moderate (often called “Monarchian”) view, God as a single divine principle, but with a steward, his elder or younger son Satan, who was responsible for the Creation of the visible world and of Man (though with God’s help). The Orthodox Church in Byzantium and the Balkans, and the Catholic Church in Western Christendom, regarded both these positions heretical principally because they denied the fundamental tenet of orthodox Christianity (as expressed in the opening statement of the Nicene Creed), that a single God created both the invisible and visible world and all things in it, including humans.
