Vasily Grossman:
When people are to be slaughtered en masse, the local population is not immediately gripped by a bloodthirsty hatred of the old men, women and children who are to be destroyed. It is necessary to prepare the population by means of a special campaign. [...] It is necessary to stir up feelings of real hatred and revulsion. [...] Experience showed that such campaigns make the majority of the population obey every order of the authorities as though hypnotized. There is a particular minority which actively helps to create the atmosphere of these campaigns: ideological fanatics; people who take a bloodthirsty delight in the misfortunes of others; and people who want to settle personal scores, to steal a man's belongings or take over his flat or job.