why people do evil...they think they're moral

…Baumeister found that violence and cruelty have four main causes. The first two are obvious attributes of evil: greed/ambition (violence for direct personal gain, as in robbery) and sadism (pleasure in hurting people). But greed/ambition explains only a small proportion of violence, and sadism explains almost none. Outside of children's cartoons and horror films, people almost never hurt others for the sheer joy of hurting someone. The two biggest causes of evil are two that we think are good, and that we try to encourage in our children: high self-esteem and moral idealism. Having high self-esteem doesn't directly cause violence, but when someone's high esteem is unrealistic or narcissistic, it is easily threatened by reality; in reaction to those threats, people—particularly young men—often lash out violently. Baumeister questions the usefulness of programs that try raise children's self-esteem directly instead of by teaching them skills they can be proud of. Such direct enhancement can potentially foster unstable narcissism.

Threatened self-esteem accounts for a large portion of violence at the individual level, but to really get a mass atrocity going you need idealism—the belief that your violence is a means to a moral end. The major atrocities of the twentieth century were carried out largely either by men who thought they were creating a utopia or else by men who believed they were defending their homeland or tribe from attack. Idealism easily becomes dangerous because it brings with it, almost inevitably, the belief that the ends justify the means. If you are fighting for good or for God, what matters is the outcome, not the path. People have little respect for rules; we respect the moral principles that underlie most rules. But when a moral mission and legal rules are incompatible, we usually care more about the mission. The psychologist Linda Skitka finds that when people have strong moral feelings about a controversial issue—when they have a "moral mandate"—they care much less about procedural fairness in court cases. They want the "good guys"-freed by any means, and the "bad guys" convicted by any means. It is thus not surprising that the administration of George W. Bush consistently argues that extra-judicial killings, indefinite imprisonment without trial, and harsh physical treatment of prisoners are legal and proper steps in fighting the Manichaean "war on terror."

- Johnathan Haidt