- Black Elk, Lakota Visionary: The Oglala Holy Man and Sioux Tradition
- Meditations: Essays on Religious Pluralism & the Perennial Philosophy
- Touchstones of the Spirit: Essays on Religion, Tradition & Modernity
- The Library of Perennial Philosophy
- The Betrayal of Tradition: Essays on the Spiritual Crisis of Modernity (Library of Perennial Philosophy)