The moral significance of the therapy-enhancement distinction in human genetics.

The therapy-enhancement distinction occupies a central place in contemporary discussions of human genetics and has been the subject of much debate.1–7 At a recent conference on gene therapy policy, scientists predicted that within a few years researchers will develop techniques that can be used to enhance human traits.8 In thinking about the morality of genetic interventions, many writers have defended somatic gene therapy,9,10 and some have defended germline gene therapy,11,12 but only a handful of writers defend genetic enhancement13, or even give it a fair hearing.14–16 The mere mention of genetic enhancement makes many people cringe and brings to mind the Nazi eugenics programs, Aldous Huxley’s Brave New World, “The X-Files,” or the recent movie “Gattaca.” Although many people believe that gene therapy has morally legitimate medical uses,17,18 others regard genetic enhancement as morally problematic or decidedly evil.19–21 The purpose of this essay is to examine the moral significance of the therapyenhancement distinction in human genetics. Is genetic enhancement inherently unethical? Is genetic therapy inherently ethical? I will argue that the distinction does not mark a firm boundary between moral and immoral genetic interventions, and that genetic enhancement is not inherently immoral. To evaluate the acceptability of any particular genetic intervention, one needs to examine the relevant facts in light of moral principles. Some types of genetic therapy are morally acceptable while some types of genetic enhancement are unacceptable. In defending this view, I will discuss and evaluate several different ways of attempting to draw a solid moral line between therapy and enhancement.22