The City And The Stars (1956) is a science fiction novel set in a far-flung Earth future of a thousand millions years from now, when the seas have dried up and the mountains have been worn down. Here, only two human population centres remain, and they are distinct in their attitudes. One is more materialistic and enjoys the trappings of a technically advanced civilisation; the other eschews these for a simpler and more philosophical life. They are estranged, and the plot concerns their reconciling by an unusually inquisitive young man who wants to explore the world.
As you may imagine, the depiction of the two different cultures is fertile ground for the author’s exploration of humankind. This is done eloquently in a way which is neither verbose or abrupt. Furthermore, his descriptions of the physical landscape and its exotic flora and fauna are vivid. Indeed, the reader will be filled with a sense of wonder and curiosity throughout the book as the protagonist encounters a diverse manner of landscapes, foreign cultures, and strange creatures.
All of this is done admirably in a compact 250 pages, in a novel which remains readable and thought provoking sixty years after publication.