Contents: preliminary consideration; what is mysticism; old basic principles; psychological aspect; ingredient of terror; nature mysticism; mysteries; some early syncretists; gnosticism; dry rot of asceticism; the logos; logos at Nicaea; demonology; dangers of ecstasy; twilights of mysticism; foregleams of Christianity; osculatory mysticism; quietism; sordid interlude; religion & social order; new mysticism.