This chapter examines Emmanuel Levinas's claim that the question of the alterity of the other cannot be separated from the question of the alterity of time, and how both questions are intertwined in both Edmund Husserl and Martin Heidegger. It begins by asking whether the Husserlian transcendental ego constitutes a sphere that is absolutely closed off to time and to the other. It then considers Heidegger's assertion that we must understand time not on the basis of eternity, but on the basis of time itself. It argues that, between ontological and ontic Dasein, there is only a “temporal” difference, a difference in the mode of the temporalization of temporality—and not, as in Husserl, a difference between a factual mortal ego and an immortal transcendental ego.