Hypnosis through history has had an interesting series of developments, rejections and later acceptance. Originally developed in 1770 by a Dr. Farnz Mesmer, hypnosis was originally called both mesmerism – a term still used today, as in mesmerize – and animal magnetism. James Braid later actually coined the term hypnosis in 1942. Braid believed that the mesmeric trance came from a physiological source or process. He believed that it was caused by prolonged optical fixation which caused parts of the brain to become fatigued and a "nervous sleep" or trance to develop. Braid used hypnosis to treat several disorders but had little success with physical conditions that were organic in nature. Other doctors however did have better results. A report from 1842 described an amputation surgery that was performed on a patient under hypnosis who felt no pain, leading to belief that hypnosis could be used as anesthesia. In the mid 1800's a Dr. James Esdaile perfumed 300 or more operations using hypnosis to control pain.

In the 1880's the new field of psychology adopted hypnosis. Jean Martin Carcot and his pupil Pierre Janet were proponents of hypnosis for psychological purposes. Later Sigmund Freud met Charcot and began to utilize hypnosis in his studies. But, hypnosis fell into disuse for a time, only to be revised in the 1930's by Clark Leonard Hull of Yale University. He was an experimental psychologist who made an advanced study of the topic. He found that hypnosis could be used as an anesthetic and post hypnotic amnesia could be induced. Still the most common use of hypnosis for many years was as entertainment by stage hypnotists or mesmerizers who would plant post hypnotic suggestions in the minds of subjects for the entertainment of the audience. Stage hypnotists still exist today.

Scientist believes that hypnosis is a way to access the subconscious mind directly. A person's subconscious mind is often working hand in glove with the conscious mind, which issues instructions. The subconscious mind takes care of those things we do automatically, like breath, walk, or driving a car. Through deep relaxation and focussing through exercise hypnotism can be used to subdue the conscious mind, to make it take a less active role. The conscious takes a back seat to the subconscious. This allows hypnosis to work, whether or medical or entertainment purposes.