Before converting to Christianity, Augustine was at one time a member of a group called the Manichaeans and this collection of works are his attempt to combat the growing threat that this religion caused to the rise and growth of the Christian church. The Manichaeans were a dualistic society that focused on the goodness of the spirit and the evil of the material. While basing their belief structure of Mesopotamian Gnosticism it is hard to say for certain that they were Gnostic themselves. Augustine shows sound arguments to counter the beliefs he reveals in this collection of writings even going so far as to have a verbal parley back and forth with a leading member of the religious movement Fortunatus.