This introduction presents an overview of key concepts covered in the subsequent chapters of this book. The book attempts to define the dual nature in Christ through the Christological debates leading up to the Council of Chalcedon, especially in its Syrian and other desert guises. It also observes a disparity between the doctrinal insistence on the full humanity of Christ and ascetic unease about the body which sometimes verged on a dualistic rather than integrated understanding of the physical and material aspects in the human person. In addition to the wealth of ascetic and Patristic sources Pauline anthropology provides a richly stocked mine of ideas about man body, its fleshly make-up and the life of the spirit within the human person. These investigations were stimulated by friction between the integrity of Christ's humanity as part of a unity of natures and the integrity of the human being.