Having used what he believes to be sound reasoning to implicate NFP in avoidable embryo deaths, he then entertains some possible pro-life responses. Since there’s little actual reasoning in Bovens arguements, I’d just as soon skip his charicatures of pro-life rebuttals. However, since they involve subtle changes to his arguments and could easily stand on their own, I’ll briefly address them, if only to highlight his slight of hand.
"So what is the alternative? If one is concerned about minimising embryonic death, then one should avoid types of contraception whereby each unintended pregnancy (due to its failure) comes at the expense of a high embryonic death rate. Given our first assumption, a condom user (who makes no distinction between HF and non-HF periods) can count on one embryonic death for each unintended pregnancy. A rhythm method user, however, should count on two to three embryonic deaths for each unintended pregnancy. Assuming a success rate of 95% for condom usage, we can count on an expectation of .5 pregnancies in 10 years. Hence, the expectation of embryonic death is .5 per ten years for a condom user, which is substantially lower than the expectation of two to three embryonic deaths per ten years on the rhythm method. Even a policy of practising condom usage and having an abortion in case of failure would cause less embryonic deaths than the rhythm method."
"So how can this argument be blocked? First, one could say that the empirical data are questionable. However, the result really depends on the simple assumption that embryos conceived outside the HF period are less viable than embryos conceived during the HF period. If this is the case, then the success of the rhythm method is contingent on a higher embryonic death rate and so every pregnancy due to a failure of the technique will come at the expense of a higher embryonic death rate—and this is all that is needed to get the argument off the ground."
If that’s the case, then the argument is grounded. Dr. Whitty explains.
"Boven’s third assumption is wholly invalid in the light of current knowledge of human reproductive physiology. The ovum lasts for about 12 hours, 24 at most; sperm may last up to 3-5 days with the support of both the appropriate types of cervical mucus and of the activity of the cervical crypts. Any conception is as viable as the next, barring a fatal genetic or developmental defect; there is no truth to the old ‘old sperm’ or ‘old ovum’ speculation, or its ‘twice as likely to be viable’, ‘lack resilience’ and ‘reduced survival chances assumption. Neither is there any truth in the ‘heightened fertility (HF)’ and ‘tail- end fertility’ idea, with or without further speculative assumptions about extrapolated comparative embryonic viability based on this innacuracy. A luteal phase of less than 11 days may be insufficient to sustain a natural conception, but this is a case for medical intervention. So all that follows based on the HF and other assumptions is invalid."
With the exception of women who have previously miscarried, there is no statistically significant difference in the viability of HF conception and non-HF conception embyros. As I’ve explained, that problem can be addressed by making simple modifactions of NFP’s rules.
"Second, one could be concerned about the death of an embryo due to an abortion but not due to IUD usage, because not providing the right environment for embryonic growth is less of a direct action than performing an abortion. This would bring in the intricacies of the action/omission doctrine. I am dubious that enough can be gleaned from the action/omission doctrine to support this distinction, but this is not the place to turn to this discussion."
I think Bovens’ notion of direct action is a bit strained. A freezer may fail to provide the right enviroment for preserving ice cream. If that failure was due to the fact that I sabotaged the thermostat, it is my fault because I have directly acted to ensure failure of the freezer.
"Third, one might draw a moral distinction between techniques that cause embryonic death (such as abortion and IUDs) and techniques that employ a mixed approach of preventing conception and increasing the likelihood of embryonic death in case conception occurs (such as the contraceptive pill and the rhythm method). There may indeed be a psychological distinction, similar to the comfort a person in a firing squad receives from not knowing that it was his bullet that killed the victim, but I do not think that this distinction has any normative force."
This argument is moot if the results of the study withstand scrutiny and experimental repetition. It’s also a rather ironic argument because it seems to me that this is exactly what supporters of abortifacient contractives are doing. That is, they seem to be saying, "I don’t know whether my IUD/pill/whatever killed the embryo or if it was spontaneously aborted because it was defective, and I don’t want to know. As long as I don’t know, I don’t have to feel guilty about possibly ending an otherwise viable life."
"Fourth, one might try to make a distinction between causing an inhospitable environmentfor embryonic survival (as in IUD and pill usage) and restricting the possibility of conception to a time when the environment is inhospitable for embryonic survival (as in the rhythm method). Again, the former may be considered to be more of a direct action than the latter, but once again, I think that this would be asking more from the action/omission doctrine than it can deliver."
I do not believe the distinction is one of means, i.e., action vs omission, but of ends, i.e., which embryos die. In the case of natural spontaneous abortions, which are the only kind an NFP failure could result in, onlydamaged embryos (genetic abnomalities, blighted ova, etc.) die. In the case of artificially induced spontaneous abortions (almost seems a misnomer, doesn’t it?), such as brought about by IUD and sometimes birth control pills, some of the embryos killed would otherwise be viable.