According to the marginal cases argument, there is no property that might justify making a moral difference between human beings and the other animals that is both uniquely and universally human. It is therefore “speciesist” to treat human beings differently just because we are human beings. While not challenging the conclusion, this chapter argues that the marginal cases argument is metaphysically misguided. It ignores the differences between a life stage and a kind, and between lacking a property and having it in a defective form. The chapter then argues for a view of moral standing that attributes it to the subject of a life conceived as an atemporal being, and shows how this view can resolve some familiar puzzles such as how death can be a loss to the person who has died, how we can wrong the dead, the “procreation asymmetry,” and the “non-identity problem.”
