Before I knew that a man could kill a man, because it happens all the time. Now I know that even the person with whom you've shared food, or whom you've slept, even he can kill you with no trouble. The closest neighbor can kill you with his teeth: that is what I have Learned since the genocide, and my eyes no longer gaze the same on the face of the world.
Majority decisions tend to be made without engaging the systematic thought and critical thinking skills of the individuals in the group. Given the force of the group's normative power to shape the opinions of the followers who conform without thinking things through, they are often taken at face value. The persistent minority forces the others to process the relevant information more mindfully. Research shows that the deciscions of a group as a whole are more thoughtful and creative when there is minority dissent than when it is absent.
We want to believe in the essential, unchanging goodness of people, in their power to resist external pressures, in their rational appraisal and then rejection of situational temptations. We invest human nature with God-like qualities, with moral and rational faculties that make us both just and wise. We simplify the complexity of human experience by erecting a seemingly impermeable boundary between Good and Evil.