Abstract: Significant effort has been devoted to locating a good argument for Kant's Formula of Humanity. In this paper, I contrast two arguments, based on Kant's text, for the Formula of Humanity. The first, which I call the ‘Valued Ends’ argument, is an influential and appealing argument developed most notably by Christine Korsgaard and Allen Wood. Notwithstanding the appeal and influence of this argument, it ultimately fails on several counts. I therefore present as an alternative the ‘Autonomy’ argument, which is largely inspired by the failings of the Valued Ends argument.