**Why is there evil, and what can scientific research tell us about the origins and persistence of evil behavior?** Considering evil from the unusual perspective of the perpetrator, Roy F. Baumeister asks, How do ordinary people find themselves beating their wives? Murdering rival gang members? Torturing political prisoners? Betraying their colleagues to the secret police? Why do cycles of revenge so often escalate? Baumeister casts new light on these issues as he examines the gap between the victim’s viewpoint and that of the perpetrator, and also the roots of evil behavior, from egotism and revenge to idealism and sadism. A fascinating study of one of humankind’s oldest problems, *Evil* has profound implications for the way we conduct our lives and govern our society.