Near the end of the Critique of Pure Reason, in the Canon of Pure Reason, Kant distinguishes knowing and believing as different species of something Kant calls “assent.” Kant says an assent that fails to epistemically warrant a knowledge claim does not qualify as believing unless it occurs in a practical relation. Despite recognizing that all the examples of believing Kant discusses in the Canon of Pure Reason fail to epistemically warrant a knowledge claim, some commentaries argue Kant’s example of believing in the existence of extraterrestrial lifeforms does not occur in a practical relation. In this paper, I explain what it means for an assent to occur in a practical relation, and I support my explanation by showing how all the examples of believing Kant discusses in the Canon of Pure Reason occur in a practical relation – including Kant’s example of believing that extraterrestrial lifeforms exist.