Selecting for Disabilities: Selection Versus Modification

This essay considers one argument used to defend parents who use preimplantation genetic diagnosis (PGD) to select for deafness and other disabilities. Some bioethicists have argued that a distinction should be drawn between genetically modifying embryos to possess disabilities and using PGD to select embryos that already present markers of them, and that the former is unethical because it inflicts avoidable harms onto the resulting children, whereas the latter is permissible because it allows children with potentially impaired abilities to exist. This essay raises doubts about whether a meaningful moral distinction can be drawn between modification and selection. Arguments which distinguish modification from selection can be understood in two ways. One is to read them as presenting a No Harm, No Foul argument. Another is to read them as presenting a Harming Versus Letting Be argument. Neither succeeds, however, either in establishing a meaningful moral distinction between modification and selection, or in showing that the second is morally permissible in contradistinction to the first.