To do the ultimate evil is to make another isolated due to the reason of this other's being not one of the race.
One cannot imagine not being human in the sense of being stripped of the membership. The choice does not seem ordinarily to exist. Hence the wordless despair, the cold, inhuman state of severance when such an extraordinary excommunication is decided and carried through.
However shattering the experience of the victim, though, it always leaves with the clarity of a solid mass in an x-ray the certainty in the mind that the perpetrator of the evil act was and will continue to remain human, all too human.