 A Canticle for Leibowitz opens 600 years after 20th century civilization has been destroyed by a global nuclear war , known as the " Flame Deluge " . The text reveals that as a result of the war there was a violent backlash against the culture of advanced knowledge and technology that had led to the development of nuclear weapons . During this backlash , called the " Simplification , " anyone of learning , and eventually anyone who could even read , was likely to be killed by rampaging mobs , who proudly took on the name of " Simpletons " . Illiteracy became almost universal , and books were destroyed en masse . 
