Kant gives what appear to be consequentialist and retributivist reasons for his claim that the state must punish criminal offenders. I argue that Kant's justification is retributivist and not consequentialist. In particular, I argue that Kant's justification is found in his argument that we must attribute to an offender's reason the judgment that she must be punished. I argue that other retributivist interpretations as well as interpretations that prioritize consequentialist reasons have little textual support. I also reconstruct an argument that Kant implies for his claim that ius talionis is the proper criterion for determining the quality and quantity of punishment.