The fourth-century theologian Augustine on the relationship of good to evil. What I like about this is how surprising it is, how in reading it you might initially think he's veering toward gnosticism, but he doesn't.
Reading religious discussions on the nature of evil are difficult for modern readers, but what I find fascinating about this is the idea that evil has to spring from good, corrupted. Interesting to think about in relation to the environmental versus genetic argument about serial killers.
Thoughts?