It isn't a book for everybody. Some people will be offended by its eccentric but unmistakably Catholic religiosity, others will find the story it tells simply too disturbing to be read with equanimity.
The story is futuristic fiction about a post-nuclear holocaust world hell-bent on repeating the mistake and next time finishing the job. It is organized in three sections, each of them a distinct narrative separated from the other two by many hundreds of years. They are joined by a common theme: human folly groping toward and eventually achieving technological mastery-and then making use of it to destroy itself.
Such sanity as exists in Miller's crazy world is found in the Church and, especially, in a monastic community founded after the first outburst of nuclear madness by an atomic scientist named Leibowitz. The founder intended that his monks, like their predecessors centuries earlier after the collapse of the Roman Empire, should serve as preservers and transmitters of civilized knowledge in a dark age.
During World War II Walter Miller flew 55 combat missions as a radio operator and tail gunner on a bomber. Among the targets: the historic monastery at Monte Cassino. Given that experience, it's hardly surprising that he took a dim view of fallen human nature and the survival prospects of a civilization ruled by technology. One hears the author's voice in the reflections of a fictional abbot:
"The closer men came to perfecting for themselves a paradise, the more impatient they seemed to become with it, and with themselves as well. They made a garden of pleasure, and became progressively more miserable with it as it grew in richness and power and beauty; for then, perhaps, it was easier for them to see that something was missing…some tree or shrub that would not grow."
Human perfection? And it is that absence, Miller suggests, which drives human beings in frustration and disappointment to the precipice of self-destruction.