Over the course of six decades, Emmanuel Levinas developed a radical understanding of time. Like Martin Heidegger, Levinas saw the everyday experience of synchronous time marked by clocks and calendars as an abstraction from the way time functions more fundamentally. Yet, in a definitive break from Heidegger's analysis of temporality, by the end of his career Levinas's philosophy of time becomes the linchpin for his argument that the other person has priority over the self. For Levinas, time is a feature of the self's encounter with the face, and it is his understanding of time that makes possible his radical claim that ethics is first philosophy. Levinas's Philosophy of Time takes a chronological approach to examine Levinas's deliberations on time, noting along the way the ways in which his account is informed by aspects of Judaism and by other thinkers: Rosenzweig, Bergson, Husserl, Heidegger. The progression in Levinas's account, Severson argues, moves through his viewing time as a gift or a responsibility in earlier works and culminates in the groundbreaking expressions of his later works in which he rests his resounding philosophy of radical responsibility on an understanding of time as diachrony. Further, by focusing on this progression in Levinas's thought, Severson brings new insight to a number of aspects in Levinas studies that have consistently troubled readers, including the differences between his early and later writings, his controversial invocation of the feminine, and the blurry line between philosophy and religion in his work. Finally, drawing on Levinas's own acknowledgment that significant work remained to be done on the concept of time, Severson considers the problems and benefits of Levinas's understanding of time and ultimately suggests some possibilities for thinking about time after Levinas. In particular, he reconsiders Levinas's account of the feminine and gender, identifies an implict 'fourth person' that functions behind the scenes of Levinas's work, and highlights the concept of hope in both a future justice and the possibility of a restoration that is not egocentric but for-the-other.