What Makes an Action Truly Moral? In this groundbreaking philosophical work, Immanuel Kant lays the foundation for a universal system of ethics rooted not in consequence, but in reason and duty. Fundamental Principles of the Metaphysic of Morals introduces the concept of the categorical imperative—a moral law derived from pure reason, demanding that we act only according to principles we would will to be universal laws. Challenging both utilitarianism and moral relativism, Kant argues that the o ...