This is the 16-century collection of spiritual, mystical works regarding the search for unity with the divine. The author wrote part of the works during his imprisonment. In those times, the author experienced bad health and spiritual condition, which inspired him for an inner spiritual search. The result of this search was the poem The Dark Night of the Soul, telling about the soul's journey to unity with God, which goes through three stages: purgation, illumination, and unity. Ascent of Mount Carmel is a treatise to the poem mentioned above, which gives practical advice on the ascetic life. Finally, the Spiritual Canticle is a metaphoric poem about the soul searching the unity with Christ, presented as a story of a wife seeking her beloved husband.