Originally published in 1915, "Practical Mysticism" is a work by one of the foremost 20th century Christian mystics, Evelyn Underhill. This work is an abridged version of Underhill's theology, and a perfect starting point for immersion into the subject.
In "Practical Mysticism," Evelyn Underhill sets out her belief that spiritual life is part of human nature and as such is available to every human being. Underhill's practical mysticism is secular rather than religious, since "it is a natural human activity."