Some critics of the normal function approach take issue with its focus on the “species-typical range”, arguing that it is insensitive to the diversity of ways in which human beings can flourish in life. They point out that those born with disabilities may be wary of biomedicine’s “fatal attraction to normalizing”.( Silvers, 1998; Asch and Block, 2011) Moreover, even when no amount of treatment can give someone “species typical” functioning, there may be compensatory technologies that can actually expand their range of opportunities beyond the norm (Silvers 1998). Should powered wheelchairs be designed to slow and stop at the same distance that walking humans would succumb to fatigue, in order to keep them from “enhancing” their users’ abilities? By the same token, the naturally gifted may find that they have no claim to treatment for injuries or accidents that merely bring them down into the “normal range”. If our champion thinkers, athletes and saints can legitimately claim treatment for problems that impair their species-optimal functioning, bringing the rest of us up to their levels should count as proper health care as well. But that leaves only the most extreme improvements on the other side of the “enhancement” boundary: if our species champions are the benchmark, only interventions that create capacities no human has had before would fall beyond medicine’s proper domain.  Individualizing the optimal functional range to individual genomic potentials will not resolve this problem, of course, to the extent that our genomes themselves become biomedically malleable. Establishing the “species-typical norm” for a particular human function is a difficult enough task, even where descriptive statistics can help. But when the boundary is “optimal” not “normal” functioning, the evidentiary foundations of the approach begin to come apart (Sculley and Rehman-Sutter 2008).