Kant argues that an understanding of the relation between morality and rational agency reveals the nature of moral rightness. Moral principles give us reasons for acting apart from our feeling or preferences. They give us reasons that apply to all rational agents alike. Principles that embody such reasons conform to a categorical imperative that states a universal law for all rational agents. Against critics who contend that this universal law is too general to tell us anything useful about right and wrong, Kant argues that it requires us to treat rational agents as ends in themselves, not to be sacrificed simply for the sake of other people’s goals. This attitude of mutual respect among rational agents is the basis for a moral and social order that realizes human freedom.
Human Freedom and Social Order: An Essay in Christian Philosophy