Okay, from what I read, which certainly wasn't the whole book, there are a few useful ideas here. Augustine does an excellent job (though unintentionally) of showing how religious doctrines do not come about by an organic, bottom up process, but are the products of artificial acts of committees and compilers. And he also shows how large institutions are necessary in order to keep a doctrine going once it gains a modicum of acceptance. But honestly, I found this work overall to be hopelessly reactionary (to be fair, it is a defense and does not claim to be anything else), but his arguments are piss-poor and he cherry picks evidence in a manner which comes across as being childish and willful. It definitely gave me a better understanding of why Christianity is such a fragmented belief system. Any religion which claims unfocused crap like this as being "foundational" is going to have huge problems down the road. Throughout all of the sections I read, I kept getting the feeling that on some level, Augustine really didn't seem to have the energy or the will to make something this ambitious work. I guess if your obsessed with early church history then it might be bearable. Otherwise, look elsewhere.