This article explores the relevance of death to the value of life. After a preliminary discussion of the human experience of mortality, I consider Heidegger’s argument that death is a condition of authenticity, Sartre’s claim that death is an externality that is irrelevant because it cannot be lived and Simmel’s theory that death is a boundary that is transcended by life. While all theories have their merits, I suggest that Simmel’s approach, which articulates well with Levinas’s ethical critique of Heidegger, (...) offers important insight into our responsibility for other people and for the survival of other forms of life. (shrink)