The Crowd

[prime]

We find that whole communities suddenly fix their minds upon one object, and go mad in its pursuit; that millions of people become simultaneously impressed with one delusion, and run after it, till their attention is caught by some new folly more captivating than the first.

https://www.gutenberg.org/files/24518/24518-h/24518-h.htm

I have never read it, but I liked this line. If you have not read the Apology of Socrates, then this is a good introduction to the problems of the herd and its defenders (Pharisees/Sophists) who are interested in means-over-ends thinking.