“When we accept that humans are animals without resorting to claims of superiority, we can appreciate and value those of us that genetic inheritance or mutation have affected, from conjoined twins to people with Angelman syndrome. Disability or ageing are not seen as threatening aberrations from the essential existence of a human but as normal occurrences among organisms, which is not to say that we do nothing to ease associated suffering or to better their lives, but that we don’t see these individuals as diverging from a superior definition of being human.”