Some hypnotists conceive of suggestions as being a form of communication directed primarily to the subject's conscious mind, whereas others view suggestion as a means of communicating with the "unconscious" or "subconscious" mind. These concepts were introduced into hypnotism at the end of 19th century by Sigmund Freud and Pierre Janet. The original Victorian pioneers of hypnotism, including Braid and Bernheim, did not employ these concepts but considered hypnotic suggestions to be addressed to the subject's conscious mind. Indeed, Braid actually defines hypnotism as focused (conscious) attention upon a dominant idea (or suggestion). Different views regarding the nature of the mind have led to different conceptions of suggestion. Hypnotists who believed that responses are mediated primarily by an "unconscious mind", like Milton Erickson, made more use of indirect suggestions, such as metaphors or stories, whose intended meaning may be concealed from the subject's conscious mind. The concept of subliminal suggestion also depends upon this view of the mind. By contrast, hypnotists who believed that responses to suggestion are primarily mediated by the conscious mind, such as Theodore Barber and Nicholas Spanos tended to make more use of direct verbal suggestions and instructions.
