Book cover featuring an illustration of US Uncle Sam-like character holding a woman.

Some time ago a bright young graduate student was driving me to a conference at a noted Midwestern university. He had a Ph.D. in molecular biology and was finishing his law degree, after which he planned to work for a biotechnology firm in the Philippines. I told him I supported human genetic and biomedical research, including stem cell research, but was concerned about the ways in which the results of this research could be misused. I asked him, "If it were possible to genetically engineer a human embryo to enhance some particular cognitive skill, would you support that?" He laughed, "Of course!" as if any other answer would be difficult to imagine. Then I asked how he would feel about a couple who wanted to create and genetically engineer an embryo to have impaired cognitive skill, perhaps because they thought people with simpler minds were happier. He thought a moment and said, "Well, that makes me uncomfortable, but I can't think of any good reason they shouldn't be allowed to do it."

A few months later I was having...