A trilogy, whose component books are: Ordinary Germans; Eichmann: Explaining Perpetrator Behaviour; and Post-War Justice For Nazi War Criminals: Context, Culpability and Legitimacy. Together the three books examine multiple levels of German complicity in the objectives and activities of the Nazi regime. The whole is an attempt to establish the nature and extent of complicity of ordinary Germans in their differing roles, and to show a parallel between their behaviour in the Third Reich and human behaviour in all cultures, societies and historical periods. The argument presented is that the decisive factor in the behaviour of both ordinary Germans and Nazi perpetrators is pursuit of personal interest. It is further posited that the optimisation of personal outcomes is the decisive causal influence on all human behaviour, regardless of culture, society and epoch.