Dualistic Heresies of the Middle Ages. The dualistic
heresies of the Middle Ages—that of the Paulicians,
who flourished in Armenia and Asia Minor between
the seventh and the tenth centuries, and continued later
in the Balkans; that of the Bogomils, whose doctrine
started in Bulgaria and spread in the Balkans between
the tenth and the fifteenth centuries; that of the
Cathari, who flourished in Western Europe in the
twelfth and the thirteenth centuries—probably sprang
not from Manicheism but, like Manicheism itself, from
Gnosticism, which had continued in the Orient. The
principle of all these dualisms is still the profound
distinction between God and the world.