Footnotes

• Competing interests None.

• Provenance and peer review Commissioned; internally peer reviewed.

• ↵i All page numbers in the text refer to this paper unless otherwise noted.

• ↵ii However, if there is, in fact, an answer to the question as to whether it's better to be born with a womb or not then one might well wonder why parents do not have an obligation to transplant a womb into a male child or remove one from a female child?6 Until a safe, effective and reliable method of successfully changing the sex of infants is developed, though, Casal is correct that my argument about sex selection is not directly relevant to person-affecting enhancements.

• ↵iii This is not to claim that every child of the ‘better’ sex will have better life prospects than every child of the ‘worse’ sex. If parents have access to all the genetic information about two embryos they may well have reason to choose an embryo that happens to be male. Nevertheless, given the difference in average life expectancy between men and women parents can significantly enhance their children by choosing on the basis of sex alone. Moreover, this information is much more readily available than other genetic information.

• ↵iv Interestingly, Casal thinks that being bigger and stronger (more like men!) would benefit women.

• ↵v I must admit that I am myself increasingly nervous about the adequacy of the influential account of health and disease, developed by Christopher Boorse, which I rely upon here.16 ,17 For a recent and powerful critique, see Kingma.18 Note that the issue that is the focus of Kingma's criticisms—the justification of the choice of reference classes within Boorse's account—is also central to the question of the plausibility of Casal’s various counter-examples here (Equalia, Dimorphia, etc). Nevertheless, my fundamental argument remains that without an account of the normal capacities of male and female human beings, and the claim that these norms are morally significant, we cannot avoid the conclusion that one sex or the other should be acknowledged to have inferior capacities unless we are willing to embrace equally problematic conclusions elsewhere in contemporary bioethical debates.

• ↵vi Again, the extent to which it is plausible to distinguish ‘species-typical function’ from that observed in statistically normal members of the species in any given environment is a key question in debates surrounding the adequacy of Boorse's account of health.

• ↵vii Indeed, as noted above, the argument for moral enhancement itself almost certainly requires the welfare of children to be sacrificed for the social good.

• ↵viii The research for this paper was supported under the Australian Research Council's future fellowships funding scheme (project FT100100481). The views expressed herein are those of the author and are not necessarily those of the Australian Research Council.