It just seems incredible to me that a doctor could abandon his Hippocratic oath and serve at Auschwitz. It seems even more incredible a doctor could do this while feeling bad about it (ie knowing what he was doing was morally wrong, but doing it anyway).
Is this true?
Follow-up question which could actually be included in the main one, how much choice did the doctors at Auschwitz have in being there? What would have happened if they refused?