In this chapter, after a general introduction to Underhill and an overall description of her text around which this book revolves, I work towards defining the concept of mysticism and speak briefly about the origins of Christian mysticism. From written reports of mystics, two interesting and important questions surface, and these questions help launch the study documented in this book. This introductory chapter also explains my reasons for choosing Underhill's text as my foundational source of reference. A major portion of the chapter consists of a presentation of the objective and method navigating this study as well as an introduction to the themes of dialecticism and sublimity, which constitute the hermeneutical framework for investigating mysticism. In the final section I offer previews of the subsequent chapters in the book.