Introduction
摘要
This introductory chapter defines the scope and terms used throughout the book. It clarifies two core senses of happiness—a short-lived feeling and a broader evaluation of life—using a brief, dictionary-based overview from major English references. The chapter notes older meanings tied to luck and fortune, contrasts them with contemporary senses emphasizing pleasure, contentment, and satisfaction, and explains that both strands remain active in current usage. It highlights how polysemy can lead readers and researchers to speak past one another unless the intended sense is specified. The chapter then sets a shared vocabulary for later chapters and provides a concise roadmap of what follows: a selective historical sketch, post-1945 developments, current meanings across disciplines, distinctions from neighboring constructs, and an organizing framework for evidence on persons, daily life, relationships, and context.