The Book of the Law by Aleister Crowley is the foundational text of Thelema, a religious philosophy focused on the discovery and pursuit of one's "True Will." Written in 1904, the book was dictated to Crowley by an entity named Aiwass and is divided into three chapters, each narrated by different deities. The central themes include the famous phrases "Do what thou wilt shall be the whole of the Law" and "Love is the law, love under will," emphasizing individual purpose and love guided by true will. The book promotes self-discovery, personal freedom, and the ushering in of a new spiritual era.