Why is it easier for a person in a foreign city to commit a crime than in his native land? What gives rise to people's fear of migrants, and how does this fear push them beyond the line of the law? How do perceptual errors drive healthy people into rage, insanity, and psychosis? Does the brain push us to commit a crime, or does it seek justification for an already made decision? Karl Jaspers, the great philosopher of the twentieth century, began his career as a psychiatrist, and he wrote his best scientific works during the years of his work in a clinic for the mentally ill. The stories of his own patients formed the basis of his works on crimes in a state of rage, reactive psychosis, as well as murders committed by migrants. The scientist wrote these works at the beginning of the twentieth century, and several decades later, in the second half of the century, he completely revised them. The works “Nostalgia and Crimes”, “Errors of Perception” and “The Doctrine of Reactive Psychoses” formed the basis of this book.