Key to the Science of Theology by Parley P. Pratt is a seminal work that offers a unique and comprehensive exploration of theology from a Latter-day Saint (LDS) perspective. Originally published in 1855, the book reflects Pratt's pioneering vision of theology not merely as a system of faith but as a science—a discipline governed by divine laws and eternal truths. A leading figure in early Mormonism, Pratt presents a bold synthesis of philosophy, religion, and governance, aiming to illuminate the deeper principles that govern both spiritual and temporal realms. In this work, Pratt discusses key Christian doctrines, including the nature of God, the role of Jesus Christ, the importance of revelation, and the eternal potential of humanity. He emphasizes the idea that spiritual knowledge is acquired through obedience to divine laws, portraying theology as a living, dynamic pursuit of truth. Pratt also addresses themes such as the resurrection, spiritual gifts, the afterlife, and the eternal progression of souls, offering a profound vision of the purpose of human existence. Beyond theology, Pratt's writings extend into practical matters of law and government, reflecting the Mormon belief in the integration of spiritual principles with societal order. He argues that true religion encompasses all aspects of life—personal, communal, and governmental—each governed by eternal laws that promote peace, justice, and freedom. Key to the Science of Theology remains a thought-provoking text for those interested in the relationship between faith and reason. Pratt's innovative blend of theology and philosophy challenges readers to see religion as a pursuit of knowledge governed by universal truths. For students of LDS theology, philosophy, or religious thought, this work offers a fascinating insight into the early development of Mormon beliefs and the visionary spirit that continues to shape the faith today.