A seasoned voyager narrates four voyages that use dramatic changes of scale and surreal societies to examine human character and institutions. He encounters miniature islanders with petty politics, giant inhabitants who cast a different moral light on manners and power, a floating island devoted to abstruse sciences and impractical inventions, and a rational equine society that contrasts cold reason with savage human behavior. Through satirical episodes and moral reflection, the journeys critique political ambition, scientific pretension, and the frailties of pride, reason, and civilization.