As a philosopher interested in biomedical ethics, I find recent advances in genetic technologies both fascinating and frightening. Future technologies for genetic therapies and elimination of clearly deleterious genes offer us the ability to get rid of the cause of much human suffering, seemingly at its physiological root. But memories of past eugenics programs gone horribly awry (whether we speak of Hitler's program, California sterilization laws and practices of the 1920s, or even contemporary practices, such as attempts to work out deals that exchange sterilization for early prison release) must make cautious our initial optimism for these generally well-intentioned programs. Most often the scientist proceeds in research with the best of intentions, but that does not make all scientific investigation worth pursuing.