In "Reason, the Only Oracle of Man; Or, A Compendius System of Natural Religion," Ethan Allen presents a compelling critique of traditional religious doctrines, advocating for a rational and empirical approach to understanding the divine. The text is structured as a systematic exposition of natural religion, emphasizing reason as the sole arbiter of truth. Allen deftly weaves Enlightenment principles with a pointed critique of dogmatic belief systems, positioning his work within the rich context of 18th-century Rationalism and Deism. His prose is both incisive and accessible, aiming to strip away the complexities of supernatural claims in favor of a more universal and reason-based spirituality. Ethan Allen was not only a prominent figure in the American Revolutionary War, but also a fervent advocate for rationalism and democratic values, which profoundly influenced his philosophical pursuits. His diverse experiences, ranging from military leadership to passionate debates over governance and belief, equipped him with a unique perspective on the conflicts between reason and religious dogma. Allen's own journey from a theologically governed society towards one rooted in Enlightenment ideals is reflected in the bold assertions made in this work. Readers seeking a thoughtful exploration of the intersection between reason and faith will find "Reason, the Only Oracle of Man" both enlightening and provocative. This book challenges conventional religious thought and invites a reexamination of one's beliefs through the lens of reason. Ideal for those interested in Enlightenment philosophy, religious studies, or the evolution of American thought, Allen's work remains a vital contribution to the discourse on natural religion.