This study of human violence begins by describing the "magnitude gap" between the victim's viewpoint and that of the perpetrator. It then goes on to explore the basic roots of evil, evil as a means to an end, revenge and egotism, and sadism. The final section looks at how people step over the line between acceptable and evil acts, then how evil can grow and spread. There is also a discussion of the human mechanism for suppressing evil - guilt - as well as our natural inclination towards ambivalence, which allows evil to flourish.