Disturbingly, in our so-called information age, pseudoscience is burgeoning, with alien abduction, "channeling" past lives, and communal hallucinations commanding growing attention and respect. In this compellingly brilliant new book, Carl Sagan argues that this is not just a cultural wrong turn, but a dangerous plunge into darkness that threatens our most basic freedoms. Casting a wide net through history and culture, Sagan examines and authoritatively debunks modern pseudoscience, as well as such celebrated fallacies of the past as witchcraft, faith healing, demons, and UFOs. By doing so, he demonstrates that true scientific thinking is critical not only to the pursuit of truth, but to the very well-being of our democratic institutions.