This book focuses on the unique philosophical relationship between Hedwig Conrad-Martius and Edith Stein. The two phenomenologists discussed and debated insights and ideas about the nature of the soul, phenomenology, personhood and individuality, animal life, nature, being, and God. This book brings together for the first time leading international scholars of phenomenology to explore the philosophical exchange between both Conrad-Martius and Stein. This is an important book for understanding the development of the phenomenological movement and key phenomenological ideas and methods. It provides a critical and comprehensive overview of the key issues that helped frame both phenomenologists' philosophical trajectories. Additionally, the ideas of Conrad-Martius and Stein are mined to address contemporary questions surrounding such topics as personal identity, animal versus human personhood, contemporary atheism, and the relationship between religion and science. The book will have great appeal to phenomenologists, philosophers, and historians of philosophy.