Their dualist doctrines, as described by controversialists, present numerous resemblances to those of the Bogomils, and still more to those of the Paulicians, with whom they are sometimes connected.
Born at Germanicia in Syria, and, before he mounted the throne, captain-general of the Anatolian theme, he had come under the influence of the anti-idolatrous sects, such as the Jews, Montanists, Paulicians and Manicheans, which abounded in Asia Minor, but of which he was otherwise no friend.
In the crusading epoch the Cathars and Paulicians carried all over Europe the old iconoclastic spirit, and perhaps helped to transmit it to Wycliffe and Hus.
But it was unquestionably from Marcionite impulses that the new sects of the Paulicians and Bogomils arose; and in so far as the western Cathari, and the antinomian and anticlerical sects ' Marcion was the earliest critical student of the New Testament canon and text.
Other similar works are his treatise in four books against the Manichaeans and Paulicians, and his controversy with the Latins on the Procession of the Holy Spirit.