“[I]f you can breed cattle for milk yield, horses for running speed, and dogs for heralding skill, why on earth should it be impossible to breed humans for mathematical, musical, or athletic ability? I wonder whether, some 60 years after Hitler’s death, we might at least venture to ask what the moral difference is between breeding for musical ability and forcing a child to take music lessons. Or why is it acceptable to train fast runners and high jumpers but not to breed them?”