The placebo response is a powerful widespread phenomenon which relieves many conditions including pain. It depends on the patient's belief or expectation that the therapy is effective. It is an unpopular topic because it is confused with quackery or seen as an expensive artifact or taken to challenge the rationale of a therapy or to mock the reality of the senses. In order to avoid taking the subject seriously, myths are invented claiming that placebos work only on hysterics or hallucinators or that they are the equivalent of doing nothing or that they act only on the mental results of pain and not on the pain itself. These myths are dismissed. A model of the brain is presented in which preconscious decisions are made as to appropriate behaviour. Pain is perceived only after a decision has been made that it is appropriate to the biological needs of the individual.