What is melancholy? How does it relate to mental disorders - dementia and craziness, rabies and lycanthropea? How do melancholy engender witchcraft and magic, stars and signs, food and sleep, pleasure and sadness, passions and excitement, poverty and wealth, selfishness and vanity, love of knowledge and excessive study of science? The author considers the essence and causes of melancholy, speaking in modern language, as a philosopher and sociologist, psychologist and psychiatrist, involving a huge number of literary sources - from Antiquity to the New Age....