This groundbreaking volume explores the intersection of dreams, medicine, and literary practice in the poetry of Chaucer and influential literary works from antiquity through the late fourteenth century. An introductory exploration considers topics such as Asclepian dream healings of ancient Greece, Old English poetry, medieval mystics, and foundational works by Hippocrates, Aristotle, Galen, Avicenna, Macrobius, and others. Detailed analyses of a series of Chaucer's poems follow. Frequently incorporating and commenting on antecedent works, these late medieval poems span various genres including the dream-vision, the romance-tragedy, and the comic tale. Dreams and medicine are woven into the fabric of these texts, the author contends, revealing distinct and often surprising insights. One such insight is the 'double potential' of literary practice, medicine, and dreams - that is, each is capable of facilitating healing and wholeness yet equally capable of causing harm and disease. Ultimately, this book shows that the joining together of medicine and dreams constitutes a vital dimension of these key works in Western literature - one that reveals a profound connection between literature and the fundamentally human experiences of disease, healing, and dreaming.