When Hannah Arendt wrote “The Origins of Totalitarianism” in the years just after the Holocaust, she struggled to explain what made the Nazi genocide so unprecedentedly evil. What separated this atrocity from all previous atrocities, she decided, was not the number of victims. It was, rather, the new institution of the concentration camp, which Arendt described as the supreme expression of the monstrous ambition of totalitarianism: to eradicate the individual human being.