This is a major new study of Kant's ethics that will transform the way students and scholars approach the subject in the future. Allen Wood argues that Kant's ethical vision is grounded in the idea of the dignity of the rational nature of every human being. He focuses for the first time on the central role played in Kant's ethical theory by the value of rational nature as an end in itself. In addition, he shows the importance of Kant's systematic theory of human nature and history, and its implications for the structure, formulation, and application of Kant's moral principles.