Robert Sparrow argues that because of women's longer life expectancy philosophers who advocate the genetic modification of human beings to enhance welfare rather than merely supply therapy are committed to favouring the selection of only female embryos, an implication he deems sufficiently implausible to discredit their position. If Sparrow's argument succeeds, then philosophers who advocate biomedical moral enhancement also seem vulnerable to a similar charge because of men's greater propensity for various forms of harmful wrongdoing. This paper argues there are (...) various flaws in Sparrow's argument that render it unsuccessful. The paper also examines whether dimorphism reduction is a more desirable outcome than male elimination, thereby further illustrating the difficulties besetting the distinction between therapy and enhancement. (shrink)