In “On Mr. Spencer's Data of Ethics,” Malcolm Guthrie engages critically with Herbert Spencer's ethical framework, meticulously dissecting the philosophical underpinnings of Spencer's approach to morality. The work is characterized by its rigorous analytical style and a clarity that challenges the reader to reflect on the implications of Spencer's theories within the broader context of ethical philosophy. Guthrie navigates the interplay between ethics and evolutionary theory, presenting a nuanced examination of how claims of moral progress are derived from biological notions, thereby placing Spencer's ideas within the late Victorian intellectual milieu that sought to reconcile science and morality. Malcolm Guthrie, a prominent Scottish philosopher and educator, was known for his combative and nuanced engagements with contemporary ethical theories. His interest in ethics developed alongside his academic pursuits in moral philosophy, leading him to critically assess Spencer, whose ideas were both influential and controversial in their time. Guthrie's background in philosophical inquiry provides a lens through which he advocates for a more robust understanding of morality that transcends Spencer's original framework, reflecting the evolving landscape of ethical thought in the late 19th century. This book is an essential read for anyone interested in the intersections of philosophy, ethics, and evolution. Guthrie'Äôs thorough critique not only clarifies the complexities surrounding Spencer's ideas but also invites readers to question the foundations of ethical reasoning itself. Scholars, students, and philosophy enthusiasts will find Guthrie'Äôs work a valuable contribution to ongoing discussions about the nature of ethics, morality, and the legacy of Victorian thought.