In A Modern Utopia, two travelers fall into a space-warp and suddenly find themselves upon a Utopian Earth controlled by a single World Government. The premise of the novel is that there is a planet (for "No less than a planet will serve the purpose of a modern Utopia") exactly like Earth, with the same geography and biology. They have, however, "different habits, different traditions, different knowledge, different ideas, different clothing, and different appliances." The narrator's double describes the ascetic Rule by which the samurai live; this includes a ban on alcohol and drugs and a mandatory annual one-week solitary ramble in the wilderness. He also explains the social theory of Utopia, which distinguished four "main classes of mind": The Poietic, the Kinetic, the Dull, and the Base. Poietic minds are creative or inventive; kinetic minds are able but not particularly inventive; the Dull have "inadequate imagination," and the Base are mired in egotism and lack "moral sense."