‘But the active ones, they were all National Socialists.’ This is how Filbert assessed the nature of participation in the Nazi Movement almost forty years after the end of the war. Filbert actively pursued a career in the Nazi security apparatus. He volunteered for service in the SS-Einsatzgruppen in the war of annihilation against the Soviet Union, and he displayed particular radicalism in implementing his commission to murder Soviet Jewry. Filbert can be regarded as falling into at least one (and quite possibly four) of the five categories of ‘ordinary people’ identified by the sociologist Michael Mann in his analysis of over 1,500 biographies of perpetrators of Nazi genocide: he was a ‘materialist killer’ (or careerist). In the words of Dr Henry V. Dicks, the British psychiatrist and psychoanalyst who interviewed Filbert at length in his prison cell in July 1969, Filbert was a ‘status-and-promotion seeking philistine’. His deputy in Einsatzkommando 9, Wilhelm Greiffenberger, concluded that Filbert ‘only had his own advancement in mind’. Simultaneously, however, Filbert also belonged to what Mann terms the ‘real Nazis’, that is, those who were ‘committed to extreme nation-statism radicalized into murderous ethnic/political cleansing. They were ideological killers’. Dicks classed Filbert ‘as a real fanatic. To persevere in accepting zealously and unquestioningly any assignment the Party offered him […] seems to me the hallmark of SS dedication.’ Indeed, the social psychologist Stanley Milgram has noted that ‘[i]deological justification is vital in obtaining willing obedience, for it permits the person to see his behavior as serving a desirable end’. Filbert's motivations for pursuing a career in National Socialism, culminating in active participation in crimes on a mass scale, were both careerist and ideological. In fact, Filbert's ambition and craving for recognition were strengthened and, significantly, justified by his ideology and his belief that he belonged to the ‘master race’. His ideology persuaded him that the career advancement, status and recognition he sought were no more than his due; he felt he had a right to success. Ideology and egotism were mutually reinforcing.