The World Inside

This is a science fiction novel, written by Robert Silverberg and published in 1971. The novel is set on Earth in the far future. The world has been badly overpopulated due to religious beliefs similar to fundamentalist christianity, and most of the action occurs in a massive pyramidal enclosed city. Note the similarlity to Isaac Asimov's novel, The Caves of Steel. The dwellers of the mega-city share scant resources, and believe that the non-proprietary sharing of everything is required in order for people to peacefully co-exist in close quarters. The sharing extends to wives and husbands, a sentiment no doubt springing from the free love movement of the mid to late Twentieth Century. Although great effort is spent to maintain a stable society, the people of the mega-city often suffer from mental illness, and in fact this befalls the books two main characters.