In a little noted passage in A Theory of Justice, John Rawls argued that genetic intervention in the traits of offspring may be morally required as a matter of distributive justice. Given that the “greater natural assets” of each “enables him to pursue a preferred plan of life[,]” Rawls wrote, the parties to the original position “want to insure for their descendents the best genetic endowment.…Thus over time a society is to take steps at least to preserve the general level of natural abilities and to prevent the diffusion of serious defects.…The pursuit of reasonable policies in this regard is something that earlier generations owe to later ones.” (Emphasis added.) Whether biological enhancement actually is a moral obligation we owe to future generations is a question that I have taken up elsewhere, but which lies beyond my scope here. If we agree with Rawls that some measure of safe and effective genetic intervention may be required as a matter of justice, it stands to ask how the distribution of genetic goods – that is, the hereditary basis of human traits – should be carried out.