The intractability of the nonidentity problem

The author, in this paper and elsewhere, defends a person-affecting approach to morality, according to which an act that harms no one cannot be wrong, together with the argument from the nonidentity problem that any act that adversely affects only those future persons who owe their existence to that act's being performed cannot properly be said to harm those future persons. Extending the logic of the nonidentity problem to cases involving not just strict numerical identity but "biographical identity" as well, the author argues that agents do nothing wrong when they raise a child under, or return a child to, a particular biographical identity, since a new biographical identity, even if more advantageous, would not make the one child better off but instead replace the one child with another child-a biographically nonidentical child-altogether.