For many years scientists within human and animal science have extensively discussed the philosophy of medicine, but never have both sides communicated on their concepts of health, quality of life and welfare, with each other. This book helps clarify the difficult but central notions of health and welfare by comparing the human and animal variants of these concepts. Split into three parts this book starts by presenting a background of some of the major theories of human health and welfare, among these are the bio-statistical theory, classical theories such as Aristotle and Bentham, as well as objectivist and subjectivist contemporary theories. This is followed by a detailed discussion of theories on animal welfare and health; these include coping, feeling and preference theories. The final part of the book tests a comprehensive conceptual framework of a holistic kind, which focuses on the individual's ability to achieve it's vital goals.