As human enhancement—germline editing, neural interfaces, advanced prosthetics—moves towardreality, it generates a pressure easily overlooked: the optimization of the human toward a sharedideal contracts the range of genetic and cognitive variation. The process is gradual, diffuse, andunauthored, and its endpoint is an irreversible narrowing of the variation on which an unforeseenfuture might depend. The intuitive remedy is preservation, the banking of the variants we still hold.This paper argues that preservation cannot do the work asked of it: storage sorts by wealth, and atthe point of use it forces a ranking of variants that reinstates the eugenic sorting it was meant toavoid. Nor can the loss be averted by selecting more wisely. Because the value of a trait is relative toenvironments that cannot be known in advance, which traits are superior cannot be seen ahead oftime; optimization toward a single ideal is therefore not merely ethically hazardous butepistemically unfounded. The paper's positive claim is that human diversity is protected not byranking lives but by a universal quality of life: a social condition, combining technical compensationwith the valorization of atypical constitutions, under which every way of being human can live well.Where no constitution carries a penalty, the motive to select dissolves rather than having to beforbidden. The argument inverts a familiar assumption: the pursuit of perfection yields fragility,while the acceptance of imperfection yields the resilience that perfection itself could not secure.