Richard Dawkins examines the growing suspicion the public has for science-based medicine, despite its track record of successes like the germ theory of disease, vaccines, antibiotics and increased lifespan. He notes a fifth of British children are currently not immunised against measles, mumps and rubella, attributing it to fears arising from a highly controversial report linking the vaccine with autism.

Dawkins points to some of science’s achievements and describes it as freeing most people from superstition and dogma. Picking up from his superstition-reason distinction in The Root of All Evil? (while recycling some footage from it), he then says reason is facing an "epidemic of superstition" that "impoverishes our culture" and introduces gurus that persuade us "to run away from reality". He calls the present day dangerous times. He returns to science’s achievements, including the fact that, by extending people's lifespan, it helps them to take more advantage of life. He turns his attention to astrology, which he criticizes for stereotyping without evidence. Having put astrology to the test and referred to larger-scale experiments, he then briefly describes the mechanics of astronomy, and then expresses frustration that 50% of the UK population – more than are members of one religion – believe in the paranormal.