 Since World War II, moral, political, and legal philosophers have become increasingly interested in the concept of evil. This interest has been partly motivated by ascriptions of ‘evil’ by laymen, social scientists, journalists, and politicians as they try to understand and respond to various atrocities and horrors, such as genocides, terrorist attacks, mass murders, and tortures and killing sprees by psychopathic serial killers. It seems that we cannot capture the moral significance of these actions and their perpetrators by calling them ‘wrong’ or ‘bad’ or even ‘very very wrong’ or ‘very very bad.’ We need the concept of evil.