In his pre-critical lectures on rational psychology, Kant employs an argument from the I to the transcendental freedom of the soul. In the (A-edition of the) first Critique, he distances himself from rational psychology, and instead offers four paralogisms of this doctrine, insisting that ‘I think’ no longer licenses any inferences about a soul. Kant also comes alive to the possibility that we could be thinking mechanisms – rational beings, but not agents. These developments rob him of his pre-critical rationalist argument for freedom. In the Groundwork, this is a serious problem; if we are not free, morality will be a phantasm for us. In Groundwork III, Kant attempts to overcome this by offering a new argument for our freedom, involving the standpoint of practical reason. In this paper, I detail these developments and present a practical and phenomenological reading of Kant’s approach in Groundwork III. I also venture a defence of this new argument.