This volume unites seventeen cutting-edge research articles about historical and contemporary issues surrounding the philosophical concept of animal. The historical issues include questions concerning the relation between the animal organism and its environment, the nature and origin of animal souls, the metaphysics of animal generation and the moral and legal standing of animals in ancient, Renaissance, early modern and late 18th/early 19th century philosophy. The contemporary issues include questions concerning the nature of animal experience and consciousness, the role of folk psychology in animal cognition research, the mereological analysis of the unity of the animal organism, and the role of animalism in theories of personal identity. Also contemporary issues concerning the status of animals in natural law, the possibility of moral emotions in non-human animals and the role of reason for understanding the relation between human and non-humans animals are discussed. All contributions have been specially commissioned for the present volume.