If you've spent much time at all arguing with those who are pro-abortion, you've doubtless heard this canard: "Scientists think some huge percentage of embryos naturally fail to implant--at least 50%. You pro-lifers don't worry as much about those but only about procured abortions. Your lack of energy expended upon attempts to protect embryos from natural implantation failure shows that you don't really believe that the embryo is human from conception. You just want to control women."
There are so many things wrong with this that it's hard to pick one. Just one is the fact that the pro-abort making this argument is talking vaguely. What precisely does he think we should be doing to "show that we care" about natural implantation failure? One's being pro-life hardly commits one to the (usually left-wing) politicization of natural death, disease, and disaster. It is normally the leftist who wants everyone to show that they care about x disease by calling for more government funding for research on x. It isn't a sign that I don't think women with breasts are human beings (!) if I don't constantly carry on and yell loudly that "we" must "do more" to try to "stop breast cancer."
The pro-abort who makes this argument also shows no awareness of how difficult it is to know what to do about natural implantation failure. Given that most of the time we don't even know when, much less why, it occurs, preventing or stopping it is incredibly difficult, as fertility doctors will tell you. In fact, if one believes that IVF is morally wrong, one would probably have reason to oppose much of the research that is done to try to figure out what causes implantation failure, since the best way to test various methods to prevent it is in an IVF context where researchers know there was an embryo in the first place. In this case, IVF embryos cannot simply be created and treated as cannon fodder for the alleged greater good of trying to find a solution to the implantation failure of other embryos. Using persons as means rather than ends, ethics, etc., etc.
So this is a pure head-fake, pure vague talking with no cash value. We're supposed to "worry about" a particular class of natural deaths in order to prove that we really believe that those who die in those cases are really human.
And then there's the question of whether we really know that such a high percentage of embryos naturally fail to implant. Very likely some do, but the inferences that bolster the statistical claim are always indirect and by no means decisive.
The bottom line is that we don't generally have to show that we believe that the members of some identifiable group are human persons by a particular amount of worry or fuss over disease and natural death that afflicts that group. How many of even the most PC liberals feel that they have to put in a daily or monthly quota of time worrying about deaths from sickle cell anemia to prove that they really believe blacks are human persons, or about deaths from Tay Sachs to prove that they really believe Ashkenazi Jews are human persons?
It makes no sense whatsoever to say that an attempt to protect members of a group from targeted, direct killing must be bolstered by equal (as measured by whom?) amounts of "worry" about natural deaths within that group, on pain of having one's belief in the humanness of the victims challenged. Even the word "protect" makes far more sense when applied to stopping deliberate killing than when applied to trying to solve some problem of disease or natural death.
So here's an analogy to use next time this nonsense comes up:
Suppose that someone wanted to make it legal to chop the heads off of unwanted five-year-olds in the U.S. Let's say for some reason they would put an upper limit of five hundred on the number of unwanted five-year-olds who could be executed--first-come, first-serve basis for applications made by the mothers. It would be an obvious red herring for that person to say, "You don't really believe that five-year-olds are human persons, because there are five-year-olds in Africa dying of malaria, a lot more of them than would be killed by people who took advantage of this legal policy we want to enact, but you aren't putting as much energy into fighting childhood malaria deaths in Africa as you are putting into fighting our attempt to legalize beheading some unwanted five-year-olds in America." Naturally we don't want kids to die of malaria in Africa. But there is a limited amount one can do to protect children from malaria (a disease borne by mosquitoes), whereas it is completely straightforward to lock people in prison (or execute people) who chop off children's heads. And it's deeply evil for government policies to put in place the principle that five-year-olds are non-persons who can be killed at will. It's just plain stupid to measure our belief that five-year-olds are truly human persons by the amount of energy we put into worrying about malaria deaths as compared to the amount of energy we put into trying to stop policies that legalize murder.