Although I reject his argument, I defend Bernard Williams’s claim that we would lose reason to go on if we were to live forever. Through a consideration of Borges’s story “The Immortal,” I argue that immortality would be motivationally devastating, since our decisions would carry little weight, our achievements would be hollow victories of mere diligence, and the prospect of eternal frustration would haunt our every effort. An immortal life for those of limited ability will inevitably result in endless frustration, since the number of significant projects that one is capable of completing is finite, but the span of time is infinite.