The Philosophical Corps, by E B Cole

Another find from the estate sale trove, this book from Gnome Press is a lot more successful than Address: Centauri. The main idea is sort of an inverse of the Prime Directive from Star Trek. When new civilizations gain spaceflight, there are two alternatives... either they make peace with the galactic sodality, or they have to be wiped out. Our Hero of the Star Fleet makes some sociological experiments to try to alter the ethical systems of pre-spaceflight systems, so that they will be friendly when the time comes. The novel is ginned together from a handful of short stories. The first section is strongest, as the idea is laid out and tested. The rest futzes around as the author gets paid by the word.

You can buy it, and or a couple other books I picked up, on ebay. But not The Moon Pool, because someone Bought It Now just a few hours after I listed it.