Manuscript on vellum. Germany, first half 13th century.

Augustine opposed the Manichaean view that there were two creations: a Realm of Light and a Realm of Darkness. In the 7th book of his Confessions he quotes his good friend Nebridius, who said the following about dualism:

That said nation of darkness, which the Manichees are wont to set as an opposing mass over against Thee, what could it have done unto Thee, hadst Thou refused to fight with it?' For, if they answered, it would have done Thee some hurt, then shouldest Thou be subject to injury and corruption: but if it could do Thee no hurt, then was no reason brought for Thy fighting with it; and fighting in such wise, as that a certain portion or member of Thee, or offspring of Thy very Substance, should he mingled with opposed powers, and natures not created by Thee, and be by them so far corrupted and changed to the worse, as to be turned from happiness into misery, and need assistance, whereby it might be extricated and purified.'