If you've opened a newspaper or magazine recently, you've probably seen splashy ads for Botox, as part of a new $50 million direct-to-consumer marketing campaign to promote cosmetic injections of botulism toxin.

The Botox campaign follows other recent news reports about the use of human growth hormones for children who are perfectly healthy, but just happen to be short. In June an advisory committee to the Food and Drug Administration recommended, at the request of pharmaceutical giant Eli Lilly, that the agency approve this "treatment."

These are not the only recent stories about high-tech human "enhancements." The year began with headlines of an alien-chasing sect that claimed to have created a cloned baby. After that story, newspapers turned to the 50th anniversary of the discovery of DNA's structure. That coverage venerated scientists as celebrities and visionaries, and made exaggerated promises about the wondrous future benefits of biomedical research.

But what if all these promises and visions of more perfect humans fall short of their fantasy-inspiring expectations? Unfortunately, there is little evidence of that kind of healthy skepticism and line of...