Children and the Argument from ‘Marginal’ Cases Amy Mullin Accepted: 19 July 2010 / Published online: 28 July 2010 # Springer Science+Business Media B.V. 2010 Abstract I characterize the main approaches to the moral consideration of children developed in the light of the argument from "marginal" cases, and develop a more adequate strategy that provides guidance about the moral responsibilities adults have towards children. The first approach discounts the significance of children"s potential and makes obligations to all children indirect, dependent upon interests others may have in children being treated well. The next approaches agree that the potential of children is morally considerable, but disagree as to whether and why children with intellectual disabilities are morally considerable. These approaches explore the moral significance of intellectual capacities, species membership, the capacity for welfare, and the interests of others. I argue that relationships characterized by reciprocity of care are morally valuable, that both the potential to be in such relationships and the actuality of being in them are morally valuable, and that many children with significant intellectual disabilities have this potential. Keywords Children . Disability . Reciprocity . Relationships This essay is part of a larger project exploring the nature of adults’ moral obligations to children. Here I explore what makes children worthy of moral consideration, by looking to the way children, especially children with severe intellectual disabilities (IDs) have functioned in what Jan Narveson has dubbed the ‘argument from marginal cases’ (1977). The argument from marginal cases is really a class of arguments claiming that if we consider a wide enough range of humans, including young children and people with severe IDs then no morally relevant characteristic will distinguish all humans from nonhuman animals. Advocates of these arguments typically conclude that nonhuman animals deserve greater moral consideration 1 than they have hitherto received, and that ‘marginal’ humans may deserve less (Frey 1980, McMahan 2003). Ethic Theory Moral Prac (2011) 14:291–305 DOI 10.1007/s10677-010-9241-z 1 A morally considerable being is one toward whom moral agents can have direct obligations, as opposed to indirect obligations such as those based on the importance of the being to another moral agent. See Warren 1997, 3. A. Mullin (*) Department of Philosophy, University of Toronto, Jackman Humanities Building, 170 St. George Street, Toronto, Ontario M5R 2M8, Canada e-mail: amy.mullin@utoronto.ca