Chapter 9

Traces of amalgamation of religions--Instances elsewhere--Essential differences of Islam and Christianity--Compromise attempted--Influence of Islam, over Christianity--Innovating spirit in Spain--Heresy in Septimania--Its possible connection with Mohammedanism--Migetian heresy as to the Trinity--Its approach to the Mohammedan doctrine--Other similar heresies--Adoptionism--Our knowledge of it--Whence derived--Connection with Islam--Its author or authors--Probably Elipandus--His opponents--His character--Independence--Jealousy of the Free Church in the North--Nature of Adoptionism--Not a revival of Nestorianism---Origin of the name--Arose from inadvertence--Felix--His arguments--Alcuin's answers--Christ, the Son of God by adoption--Unity of Persons acknowledged--First mention of theory--Adrian---Extension of heresy--Its opponents--Felix amenable to Church discipline--Elipandus under Arab rule--Councils--Of Narbonne--Friuli--Ratisbon--Felix abjures his heresy--Alcuin--Council of Frankfort--Heresy anathematized--Councils of Rome and Aix--Felix again recants--Alcuin's book--Elipandus and Felix die in their error--Summary of evidence connecting adoptionism with Mohammedanism--Heresy of Claudius---Iconoclasm Libri Carolini--Claudius, bishop of Turin--Crusade against image-worship--His opponents--Arguments--Independence--Summoned before a Council--Refuses to attend--Albigensian heresy 114-136