This list is derived from the book "50 Spiritual Classics: Your Shortcut to the Most Important Ideas on Self-Discovery, Enlightenment, and Purpose" (Tom Butler-Bowdon).
From the Introduction: "50 Spiritual Classics is less about religion or theology than personal spiritual awakening and the expansion of awareness. Consequently, it focuses on the life stories of many well-known spiritual figures, including dramatic conversions or increases in faith, but also the slow discovery of purpose over a lifetime."
I don't believe the ordering of the books is a form of ranking.
