What are we to think about the fact that Nature (and for believers, Nature's God) profligately creates and destroys human embryos? John Opitz, a professor of pediatrics, human genetics, and obstetrics and gynecology at the University of Utah, testified before the President's Council on Bioethics that between 60 and 80 percent of all naturally conceived embryos are simply flushed out in women's normal menstrual flows unnoticed. This is not miscarriage we're talking about. The women and their husbands or partners never even know that conception has taken place; the embryos disappear from their wombs in their menstrual flows. In fact, according to Opitz, embryologists estimate that the rate of natural loss for embryos that have developed for seven days or more is 60 percent. The total rate of natural loss of human embryos increases to at least 80 percent if one counts from the moment of conception. About half of the embryos lost are abnormal, but half are not, and had they implanted they would probably have developed into healthy babies.

As far as I know, bioconservatives like Robert George do not advocate the rescue of naturally conceived unimplanted embryos. But why not? In right-to-life terms, normal unimplanted embryos are the moral equivalents of a 30-year-old mother of three children.

Stepping onto dangerous theological ground, it seems that if human embryos consisting of one hundred cells or less are the moral equivalents of a normal adult, then religious believers must accept that such embryos share all of the attributes of a human being, including the possession of an immortal soul. So even if we generously exclude all of the naturally conceived abnormal embryos -- presuming, for the sake of theological argument, that imperfections in their gene expression have somehow blocked the installation of a soul -- that would still mean that perhaps 40 percent of all the residents of Heaven were never born, never developed brains, and never had thoughts, emotions, experiences, hopes, dreams, or desires.