Hypnosis

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Hypnosis is an induced condition of narrowed attention and heightened responsiveness to suggestion, in which a person becomes unusually willing to act on, or experience as real, what is proposed to them. What exactly the state is — a distinct mode of consciousness, a form of focused absorption, or simply a social role enacted with conviction — has been argued for two centuries and remains unsettled.

Its ancestor was a theory of healing. In 1770s Vienna and then Paris, the physician Franz Anton Mesmer claimed to cure illness by redirecting an invisible fluid he called animal magnetism, passing his hands over patients until they fell into crises and recovered. A French royal commission in 1784, with Benjamin Franklin among its members, tested the fluid and could find none; the effects, it concluded, came from imagination. The verdict discredited the fluid but not the phenomenon. One of Mesmer’s followers, the Marquis de Puységur, soon described patients who sank not into crisis but into a lucid, sleeplike calm in which they spoke and obeyed — what he called artificial somnambulism, and what later observers would recognise as the hypnotic trance itself.

The modern name and the turn toward physiology came in the 1840s, when the Scottish surgeon James Braid — practising in Manchester, and persuaded after watching demonstrations of mesmerism in 1841 that the effect was real but the magnetic fluid a fiction — recast it as a nervous state brought on by fixed attention. In Neurypnology (1843) he called the condition neuro-hypnotism, nervous sleep, soon shortened to hypnotism, from the Greek for sleep. The coinage outran his confidence in it: Braid came to see that the state was not sleep at all, and spent his later years pressing a replacement — monoideism, the mind fixed on a single idea — but the word had already escaped him, and it is the one that survives.

Late in the century two French schools divided over its nature. At the Salpêtrière in Paris, Jean-Martin Charcot treated deep hypnosis as a symptom of hysteria, a pathology of the nervous system that unfolded — in his patients, at least — through fixed bodily stages. At Nancy, Hippolyte Bernheim and Ambroise-Auguste Liébeault held instead that it was suggestion at work in ordinary minds, and demonstrated it on ordinary patients. Nancy won. Charcot’s stages proved hard to reproduce outside the Salpêtrière; the suggestion account broadly prevailed, and fed directly into the early thinking of Freud, who studied under Charcot, visited Nancy, and used hypnotic technique before abandoning it.

Running alongside this clinical history was an occult one. Mesmer’s fluid, drained of medical respectability, flowed into Spiritualism and the nineteenth-century revival, where the entranced “magnetic sleeper” became a model for the medium and the clairvoyant, and where claims of mind-reading and travelling vision at a distance gathered around the magnetic state. The Society for Psychical Research, founded in 1882, took hypnotic suggestion as one of its serious subjects. Theosophical and later esoteric writers absorbed the language of magnetic influence into accounts of will, the subtle body, and unseen forces between persons.

Practitioners across these worlds believed the trance opened access to something the waking mind held closed — healing, hidden memory, latent powers of perception. Scholarship has been steadily more cautious: the reliably demonstrable effects are those of suggestion, expectation, and absorbed attention, while the grander claims of the magnetic tradition have not survived controlled testing.

The old quarrel over what the state is continues in modern dress, a question still under study. In the 1970s Ernest Hilgard proposed neodissociation — hypnosis as a genuine division of consciousness, dramatised by his “hidden observer” experiments, in which deeply hypnotised subjects who reported no pain could register, through a separate channel, how much it had hurt. The sociocognitive school of Theodore Barber, Nicholas Spanos, and their successors answered that no special state is needed: hypnotic responding is what absorbed, motivated people do with suggestion, expectation, and a well-learned role — and the hidden observer itself could be conjured or reshaped by changing the instructions. Neither camp has driven the other from the field. The American Psychological Association’s hypnosis division now defines it neutrally — focused attention, reduced peripheral awareness, a heightened capacity to respond to suggestion — a wording chosen, its authors note, to leave every theory of mechanism in play.

Its clinical standing, meanwhile, has firmed where its theory has not. That hypnotic suggestion can reduce pain is an established finding: a 2019 meta-analysis of eighty-five controlled trials found substantial analgesia, strongest in highly suggestible people given direct suggestions for relief. Gut-directed hypnotherapy for irritable bowel syndrome has performed well enough in trials to enter gastroenterological guidance. Against this stands the version most people have seen — the stage act, built on the few highly responsive volunteers it finds — and the gravest modern misadventure: the use of hypnosis in the 1980s and 1990s to “recover” buried memories. Reviews found hypnotically refreshed recollection not more accurate than ordinary recall but less — fluent, confident, and partly confabulated — and courts learned to turn it away. The technique that eases pain and the technique that built false memories are the same technique under different instructions. The state is real enough to measure; what passes through it has been the long argument.

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