What is the fine-grained topic of the following text: And yes, a singularly striking image and idea meant to provoke and inspire -- the dual aims of art -- and the signal visual note to echo the thoughts of the book: "Extraordinary Popular Delusions and the Madness of Crowds," a history of popular folly by Scottish journalist Charles Mackay, first published in 1841. Only return the topic.
"Extraordinary Popular Delusions and the Madness of Crowds" by Charles Mackay