Abstract: Preimplantation genetic diagnosis (PGD) refers
to procedures to test genetically embryos in vitro. One means to create
“designer babies” is to produce several embryos in the lab and
then use PGD to select a candidate (or candidates) for implantation. Those
embryos not selected for implantation are typically destroyed or cryogenically
preserved. Presently, PGD is used mainly for ‘negative selection’:
assaying for genetic abnormalities associated with monogenetic diseases
like Huntington’s disease, and chromosomal irregularities such as
Robertsonian translocations. Increasingly, PGD is employed for ‘positive
selection’, for reasons other than attempting to detect genetic abnormalities,
e.g., it is has been used to select embryos for tissue matching to save
an elder sibling, and for gender selection. In the near term, there is the
distinct possibility that it could be used to select for genes associated
with the potential for increased muscle mass, perfect pitch, or high IQ.
Clearly there are a number of important moral questions and issues that
arise from the use and prospective expansion of positive selection. This
paper considers one objection: since embryos are persons, and positive selection
involves the destruction of so many embryos, positive selection harms persons.
This paper argues that even if we grant the (contested) claim that embryos
are persons, positive selection does not harm the persons created through
this process. That is, this paper has the counterintuitive conclusion that
a policy that permits positive selection cannot be said to harm those persons
created, even if it is foreseeable that tens of thousands of persons will
be killed through this process. The argument is an application of Parfit’s
famous ‘non-identity’ problem. Time permitting, I will show
that there is a contradiction in some of the best-known applications of
the non-identity problem.
