One thing that disturbs people about Earth Abides is its incredible humbling realism about the human condition. People who read it come away profoundly unnerved by the idea that civilization is not something guaranteed to come into existence if we lose it and that it requires an enormous convergence of many different kinds of stimulus to create the energies needed within a race of men to bring it into being. Even the most gifted races of people on the Earth can barely hold it together in the best of times, George Stewart shows us how easily it can all fall apart and remain in a primeval condition for untold generations.
http://www.amazon.com/Earth-Abides-George-R-Stewart/dp/03454...
From one of the reviews:
One thing that disturbs people about Earth Abides is its incredible humbling realism about the human condition. People who read it come away profoundly unnerved by the idea that civilization is not something guaranteed to come into existence if we lose it and that it requires an enormous convergence of many different kinds of stimulus to create the energies needed within a race of men to bring it into being. Even the most gifted races of people on the Earth can barely hold it together in the best of times, George Stewart shows us how easily it can all fall apart and remain in a primeval condition for untold generations.
http://www.amazon.com/review/R3L6EVT6CXOAFM/ref=cm_cr_dp_tit...