A Canticle for Leibowitz is a great sci-fi thought experiment on the subject. Having survived (barely) world nuclear war, a monastery seeks to aggregate whateve

A Canticle for Leibowitz is a great sci-fi thought experiment on the subject. Having survived (barely) world nuclear war, a monastery seeks to aggregate whatever fragments of information they can (notably they mysterious note "Pound pastrami, can kraut, six bagels—bring home for Emma"), and try to rebuild society without inevitably repeating the great conflagration.