Preview of Cities in Flight Summary:

To a very great extent, Blish's social concerns are his great theme in Cities in Flight. America, he suggests, is at a crossroads. Western civilization is wearing out in a very real sense and is about to be replaced by something new, what Blish rather clumsily labels Earthmanist Culture. Through the four books of the tetralogy readers see this culture grow, pass through the various stages predicted by Spengler and then itself begin to decay. Blish ends the series with the ultimate in cultural collapses as Mayor Amalfi, protagonist of much of the series, intentionally sets off an explosion which will destroy, and then recreate, the entire galaxy.

Another theme of some importance here is the necessity of faith and, more specifically, a faith based upon rational analysis. Blish's main characters are not conventionally religious people, but they are believers of a sort and they have an abiding...