Ethics is Nicolai Hartmann's magnum opus on moral philosophy. Volume 1, Moral Phenomena, is concerned with the nature and structure of ethical phenomena. Volume 2, Moral Values, describes all values as forming a complex and imperfectly known system. The final volume, Moral Freedom, deals with one of the oldest puzzles in both philosophy and theology: the individual's freedom of the will.

Freedom of the will is a necessary precondition of morality. Without it, there is no morality in the full sense of the word. In Moral Freedom Hartmann sets out to refute the determinist view that freedom of the will is impossible. Following Kant, while rejecting his transcendentalism, Hartmann first discusses the tension between causality and the freedom of the will.

The tension between the determination by moral values and the freedom of the will is next examined, a crucial issue completely overlooked by Kant and virtually all other modern philosophers, but recognized by the scholastics. Why should we believe in the freedom of the will with regard to the moral values? Are there good reasons for thinking that it exists? If freedom of the will vis-a-vis the moral values does exist, how is it to be conceived? Moral Freedom concludes with the famous postscript on the antinomies between ethics and religion.

Hartmann's Ethics may well be the most outstanding treatise on moral philosophy in the twentieth century. Andreas Kinneging's introduction sheds light on the volume's continuing relevance.