Birgitta Mark shows how mystical experience covers three aspects of a person's general experience: mystical ideas, mystical states of consciousness and mystical development. In this comprehensive and balanced study, she examines the state and theory of mysticism, explores the credibility of evidence for mystical experience, including scientific theories of consciousness and neuronal activity and how they influence mysticism, delves into the writings and subsequent interpretations of the mystical experience of John of the Cross and connects evidence and hypothesis within his writings. The author notes that her own understanding of mystical states of consciousness is based upon S. A. Greenfield's theory of consciousness and A. R. Damasio's theory of emotions. In her own view, she says, the main cause of the promotion of mystical development is the recurrence of such mystical states of consciousness. This well-researched book would be of interest to scholars of religion, mysticism, and psychology and others who wish to learn more about our understanding of mystic states and how they affect and are affected by the persons who have experienced them throughout history.