  Some critics (Sparrow 2012) have argued that advocates of liberal eugenics face a problem if they reject the idea that some conception of human nature or of normal human capacities matters for debates about genetic improvement. They must accept that parents’ have reasons to choose some traits in spite of repugnant consequences, or that parents’ choices regarding some human traits must take into account the interests of society. Others contend that proponents of liberal eugenics simply fail to appreciate the historicity of the human condition and view human beings as a collection of parameters that can be optimized in isolation of each other (Nordmann 2007).