Suggestion
The sensitiveness to suggestion of the entranced subject is the characteristic and invariable accompaniment of the hypnotic state, and is also a distinctive feature of hysteria. Indeed, many modern scientists give to hypnotism the name Suggestion." An abnormal suggestibility implies some measure of cerebral dissociation. (See Hypnotism.) In this state every suggestion advanced by the operator, whether conveyed by word, gesture, or even unconscious glance, operates with abnormal force in the brain of the subject, as being relieved from the counterexcitement of other ideas. In the view of Professor Pierre Janet all suggestibility implies a departure from perfect sanity, but this, though perhaps true in the strictest sense, is somewhat misleading, since all are more or less amenable to suggestion. In hypnotism and hysteria, however, the normal suggestibility is greatly exaggerated, and the suggestion, meeting with no opposition from the recipient's critical or judicial faculties (because there are no other ideas with which to compare it) becomes for the time his dominant idea. The suggestion thus accepted has a powerful effect on both mind and body, hence the value of suggestion in certain complaints is incalculable. The " miracles" wrought by Christian Scientists, the efficacy of a pilgrimage to Lourdes, the feats of "healing mediums " all testify to its powerful effect. Post-hypnotic suggestion is the term applied to a suggestion made while the subject is entranced , but which is to be carried out after he awakes.
Sometimes an interval of months may elapse between the utterance of a command and its fulfilment, but almost invariably at the stated time the suggestion is obeyed, the recipient is perhaps unaware of the source of his impulse, not finding adequate logical grounds for the action he performs, or perhaps automatically lapses into the hypnotic tic state. Auto-suggestion does not proceed from any source, but arises in one's own mind, either spontaneously or from a misconception of existing circumstances , as in the case of a person who drinks coloured water under the impression that it is poison, and exhibits every symptom of poisoning. Auto-suggestion may arise spontaneously in dream, the automatic obedience to such suggestion often giving rise to stories of " veridical" dreams. The outbreaks of religious frenzy or ecstasy which swept Europe in the Middle Ages were examples of the results of mass-suggestion-i.e., suggestion made by a crowd, and much more potent than that made by an individual.
Cases of so-called collective hallucination may be referred to the same cause . Suggestion is doubtless responsible to some extent for clairvoyant and mediumistic faculties, and on the whole enters largely into the study of psychic science.