Aside from his unpublished manuscripts, Ostad Elahi’s written works are essentially found in three books published during his lifetime: Knowing the Spirit, Demonstration of the Truth, and Commentary on The Book of the Kings of Truth. Although his unique style and innovative reflections were more readily expressed in his oral teachings, these scholarly books reveal the nature and scope of the author’s research, as well as the extent of his expertise in the fields of philosophy, theology, and religious history.