In this treatise, Augustine really takes the gloves off and takes the fight to the Manicheans. As most students of Augustine know, prior to his conversion, Augustine was himself a Manicheans and this made him a vociferous critic of theirs after his conversion. And he applies the inside knowledge he had of the group here by quoting several times from the writings of Mani in order to refute those statements with his own doctrine and the Bible. Key to the heresies of the Manichaeans, from Augustine’s perspective, was their teaching on the nature of good and evil. They believed in good and evil as two completely separate forces and/or entities; Augustine believed that all things, the natural world, the human race, etc., were created good by God and that evil was what occurred when that natural goodness was corrupted by selfishness, cruelty, self-indulgence or other sins. Thus, good and evil were at war in every human heart; no person was completely good or completely evil in this life, only doing more or less well in the fight against evil behavior. I mean, to the degree I have a dog in this fight, I’m with Augustine on the basics here, though not on every specific. But he makes a good, compelling case and there’s a spark to this treatise that comes across; he’s genuinely passionate about this issue as it cuts to the very heart of his personal theology. Augustine explores these themes, of good versus evil and the Manicheans, in other treatises, but this is the most explicit of those that I’ve read, so if you really want to get a handle on one of the most important elements of Augustine’s theology and career, this is the one to read. 3 ½ stars.
tl;dr – one of Augustine’s most explicitly anti-Manichean treatises, this one is passionate, compellingly argued and an important entry in his bibliography. 3 ½ stars.