In the corpus of Western mystical literature, many writers claim that mystical union melds the human soul with God, exacting a temporary loss of awareness of their being apart from the divine. This phenomenon particularly intrigued Christian mystics in the late Middle Ages, a period coinciding with a noted increase in first-person narration and a renaissance of the idea of selfhood as a central concern in literary texts. This study argues that mystical writers face a unique challenge in conveying their sense of standing at a liminal point or threshold, inbetween states of being, negotiating (before the gaze of their readers) where the "self" ends and the divine other begins. Many assert that the ineffable nature of their experience makes this impossible to convey directly. This dissertation traces representations of the experiencing and narrating I in mystical literature to analyze how writers portray such a liminal state. After exploring liminality as a valuable critical concept for understanding mystical narrative, and as a central component of medieval Christian mystical experience, focus turns to the texts of Elizabeth of Spalbeek, whose "text" is actually a performance, and then to Marguerite Porete and Julian of Norwich, mystics from Lowland regions and England, but all of whose works circulated in some form in late medieval England. The author argues that these mystics are distinctive because they creatively manipulate conventions of narrative in order to represent spiritual experience and its potentially disruptive, divisive effects on perceptions of selfhood and ontological status. Evidencing a keen awareness of how consciousness and its divisions can be represented in narrative, they turn to structures that destabilize the narrating voice or persona, including dialogic discourse that melds multiple voices, inverted chronologies that suspend time, and recursive patterns, and use narrative form to depict their experiences. The study‟s claims proceed from close analysis of the texts in conversation with discourses of narratology, speculative theology, performance theory, anthropology, and psychoanalytic and philosophical theories of the subject. The dissertation bridges scholarship on narrative and mysticism, and contributes to the history of subject-formation and the medieval development of a literature of the self.