While the Christian church has experienced extraordinary growth over the last century, Western culture has continued its seemingly inexorable drift into post-Christian forms. The contrast between our burgeoning churches and the scant impact that Christians have on public policy, the university, or the professions is distressing. And nowhere is this development more evident-and more consequential-than in the field of bioethics, where the dignity of human beings is constantly open to redefinition, and where much of our inheritance is coming under withering fire from those whose values are...