The humanity formulation of Kant's Categorical Imperative demands that we treat humanity as an end in itself. Because this principle resonates with currently influential ideals of human rights and dignity, contemporary readers often find it compelling, even if the rest of Kant's moral philosophy leaves them cold. Moreover, some prominent specialists in Kant's ethics have recently turned to the humanity formulation as the most theoretically central and promising principle of Kant's ethics. Nevertheless, it has received less attention than many other aspects of Kant's ethics. Richard Dean offers the most sustained and systematic examination of the humanity formulation to date. He presents an original analysis of what it means to treat humanity as an end in itself, and examines the implications both for Kant scholarship and for practical guidance on specific moral issues.