This book concerns the nature of ethics and the relation between ethics and politics in the philosophy of Danish philosopher and theologian K. E. Løgstrup. In the book, Løgstrup argues that apart from deontology and teleology, there is a third main tradition within philosophical ethics, which he calls ontological ethics. According to Løgstrup, ontological ethics is rooted in the fundamental conditions of human life and is closely related to Martin Luther’s natural law ethics. Løgstrup sees the fundamental ethical relationship between humans as one of interdependence based on mutual vulnerability. In this respect, Løgstrup is reprising ideas from his earlier work The Ethical Demand (1956), where he introduced his ethical position. In the present book, Løgstrup connects his understanding of the ethical demand with his new key ethical conception of sovereign expressions of life, a concept he introduced a few years earlier in his 1968 Controverting Kierkegaard, but did not then discuss in relation to the ethical demand. Finally, Løgstrup also ventures into the area of political philosophy, discussing how it is possible to connect his own ontological ethics to politics.