Any inquiry into the meaning and implications of the prolongation of the human lifespan requires an investigation of its metaphysical basis and its ethical outcomes. This chapter explains a series of metaphysical and ethical claims about lifespan extension. It highlights a number of arguments that are typically put forward against these claims, and shows the ways in which they are mistaken. Two such claims given in the chapter are: (1) aging and life stages are neither wholly constituted by biological givens, (...) nor wholly understandable in terms of biological parameters; instead, aging and life stages are, in crucial ways, socially constructed; and (2) death is bad, and other things being equal, a longer life is a better life. (shrink)