Ethicist Luc Bovens raises some awkward questions about the Catholic Church's favored method of contraception, as reported in the Sydney Morning Herald blog Dissection:
Part of Catholics' opposition to the contraceptive pill, he points out,
is that it in the event that a woman ovulates despite it and the egg is
fertilised, then the pill's effect on the lining of the uterus may
prevent the resulting embryo from implanting. Since, according to
Church doctrine, life begins at fertilisation then that can technically
be interpreted as an abortion. Ditto for the intrauterine device (IUD).
In natural menstrual cycles, free from hormonal or pharmaceutical or
mechanical manipulation, there is an optimal time of conception -
within a day or two of the egg being released from the ovary. Leave
them too long and they start to pass their prime, less able to carry
the genetic recipe for a healthy baby.
So, Bovens says in the Journal of Medical Ethics,
it's reasonable to assume that some of the rhythm method's
effectiveness comes not from preventing the egg and sperm getting
together in the first place, but from the creation of runt embryos that
don't stand a chance of passing muster in the great Darwinian survival
race. Add a decaying uterus lining later in the cycle and the poor
clump of cells doesn't stand a snowball's.
The same argument could apply to a newly released egg that is
fertilised by geriatric sperm, still hanging around from before the
period of abstinence.
"If it is callous to use a technique that makes embryonic death likely
by making the uterine wall inhospitable to implantation," Bovens
writes, "then clearly it is callous to use a technique that makes
embryonic death likely by organising one's sex life so that
[fertilised] ova lack resilience and will face a uterine wall
inhospitable to implantation."
I have never understood Catholic opposition to barrier contraception. Now it makes even less sense. Is it better to kill an embryo or to prevent one from forming? Somebody's argumentation needs some serious tweaking.