When confronted by a range of violent actions perpetrated by lone individuals, contemporary society exhibits a constant tendency to react in terms of helpless, even perplexed horror. Seeking explanations for the apparently inexplicable, commentators often hurry to declare the perpetrators as “evil”. This question is not restricted to individuals: history has repeatedly demonstrated how groups and even entire nations can embark on a criminal plan united by the conviction that they were fighting for a good and just cause. Which circumstances occasioned such actions? What was their motivation?Applying a number of historical, scientific and social-scientific approaches to this question, this study produces an integrative portrait of the reasons for human behavior and advances a number of different interpretations for their genesis. The book makes clear the extent to which we live in socially-constructed realities in which we cling for dear life to a range of conceptions and beliefs which can all too easily fall apart in situations of crisis.