Part Two is the structural heart of the book. Part One was theory — what mysticism is, how it relates to theology, philosophy, psychology, and magic. Part Two is the road map. Underhill takes the threefold pattern that Christian writers had inherited from Pseudo-Dionysius (purgation, illumination, union) and expands it into a five-stage Mystic Way: Awakening, Purgation, Illumination, the Dark Night, and Union. The Blake epigraph sets the tone — the soul is the pilgrim, the stages are permanent landmarks the pilgrim passes through. This becomes the framework that everyone after Underhill (Inge, Knowles, von Balthasar, Merton, McGinn) writes against, modifies, or argues with.Standard Underhill scholarship; see Dana Greene, Evelyn Underhill: Artist of the Infinite Life, on the influence of the Mysticism map on twentieth-century academic mysticism.