The Enlightenment bequeathed to us the notion that the human mind can and should dominate over nature—that there is nothing we cannot know or should not attempt. And, in fact, there is something to be said for this position, since a truthful historian has to admit that standards of living have generally been greatly bettered by the technology of the last two centuries. Without confidence in our ability to remake nature, the great medical advances of the nineteenth and twentieth centuries would never have been possible: antisepsis, the discovery of the tuberculosis bacillus, sulfa drugs, the polio vaccine. Like twentieth-century researchers who faced polio and smallpox, Mark Walker has perhaps identified the central ethical malady of our twenty-first century civilization—how the lack of virtue impedes our moral progress. And just as biological researchers sought to use science to eradicate these diseases, so Walker seeks to use genetic manipulation to eradicate evil.