Apperception is the ability to identify a stable domain of objects in reference to a stable (i.e., temporally extended) sense of self. Heidegger borrows the term “apperception” from Husserl and Kant (who borrowed it, in turn, from Leibniz). Heidegger’s use of this term sheds light on his interpretation of Kant’s Critique of Pure Reason, his interpretive disagreements with the neo-Kantians, and his own criticism of Kant’s account of the self.