the afterlife. The opening of the text introduces the subject matter by outlining how the phenomenon of nightmares has significantly influenced the formation of certain erroneous beliefs, which flourished particularly between the 15th and 18th centuries. The author emphasizes the psychological aspects of these beliefs, suggesting that they stem from intense emotional experiences rather than historical or material explanations. Specifically, the text discusses how night terrors induce vivid feelings of fear and helplessness, contributing to superstitions regarding evil spirits and other supernatural phenomena that emerged during the Middle Ages, setting the stage for a deeper psychodynamic exploration throughout the rest of the work. (This is an automatically generated summary.)