" Hence the problem was how to overcome not so much their conscience as the animal pity by which all normal men are affected in the presence of physical suffering. The trick used by Himmler--who apparently was rather strongly afflicted with these instinctive reactions himself--was very simple and probably very effective; it consisted in turning these instincts around, as it were, in directing them toward the self. So that instead of saying: What horrible things I did to people!, the murderers would be able to say: What horrible things I had to watch in the pursuance of my duties, how heavily the task weighed upon my shoulders! "

― Hannah Arendt , Eichmann in Jerusalem: A Report on the Banality of Evil