Charles McKay's book is a compilation of the most outstanding delusions and follies of mankind: from pyramid schemes to religious psychoses. It has become a classic work on mass mania, mob behavior and human stupidity. The "delusions" and "madness" set forth in the book refer to the chronic "diseases" of mankind. Financial pyramid schemes, corruption of power, falsification and self-deception of imaginary healers and prophets - all this was, is and will be.