The Norwegian mass killer Anders Behring Breivik argues that he killed to do good for his country. Adolf Eichmann, one of the major organisers of the Holocaust, displayed neither guilt nor hatred, claiming he bore no responsibility because he was simply 'doing his job'. It was for him that the phrase ‘the banality of evil’ was coined. Ivan Milat, however, had a life-long history of behavioural disturbance and a propensity for sadistic violence. So how do we understand the problem? Is it just a lack of empathy or is there more than this to the problem of evil?