I believe the book is written in the genre of science fiction, may seem interesting. It's about the fact that humanity is a single consciousness. But a single consciousness, when it has hooked the dark entity.
http://www.klex.ru/f0
Colin Wilson "the mind Parasites"
Re: Colin Wilson's "mind Parasites"
Good book. I read a long time ago. Here we can recommend books namesake Robert A. Wilson. Also an interesting concept.