This chapter considers the rationales used by individuals when committing and justifying human rights abuses—how they calculate, to the best of their knowledge, the advantages and disadvantages of abusive behavior. It challenges the view pervasive in some accounts of crime and mass atrocity that perpetrators are insane, irrational, or psychologically (or biologically) abnormal. The chapter first examines the many ways that perpetrators rationalize their actions since nearly every account of systemic, long-term abuse includes a large role for rationalization. In particular, it discusses three ways that perpetrators rationalize their crimes: exceptional circumstances, avoidance of responsibility, and routinization. It then describes some of the perceived benefits of criminal abuse such as psychological superiority, intelligence, and monetary benefits, as well as the possible penalties for human rights abuses. The chapter concludes by addressing the issue of the credibility and effectiveness of deterrence.