James Braid

Braid went to a mesmeric demonstration in Manchester in November 1841 intending to catch a fraud. He satisfied himself instead that the subjects really were in an unusual state, and then did something no mesmerist had done: he separated the observation from the explanation. If the state was real, he reasoned, it did not follow that any fluid had passed from operator to subject, and he tested this by having people fix their gaze on a bright object held slightly above the line of sight, with no passes, no magnets and no operator claiming to project anything. They went under. From that he concluded that the cause lay in the subject's own nervous system, in sustained attention and the expectation attached to it, and that the operator merely provided the occasion. He coined neuro-hypnotism for the state, from the Greek for sleep, and later regretted the name, since the state is not sleep, but by then it had been shortened to hypnotism and had stuck.

The full account appeared in Neurypnology in 1843. The move cost him the mesmerists, who regarded the fluid as the whole point, and it did not immediately win him the medical establishment either, which was inclined to treat anything descended from mesmerism as disreputable. He spent the rest of his career arguing on both fronts at once, and the term he coined outlived nearly everyone in the argument.

The 1784 royal commission had shown that the effects of animal magnetism followed the subject's belief rather than the magnetiser's passes, and the usual reading of that verdict, then and now, was that the whole business was empty. Braid's contribution was to notice that the commission had established something positive and nobody had picked it up: if belief and attention can produce insensibility to pain and dramatic behavioural change, then belief and attention are doing something worth studying in their own right. He kept the phenomenon, discarded the fluid, renamed the field and handed it to medicine. Surgical anaesthesia by suggestion was practised on that basis, notably by James Esdaile in India, in the years just before ether made the question moot.

The later French schools at Nancy and at the Salpetriere argued at length about whether suggestion or a pathological susceptibility was the essential factor, and the Nancy position, which is close to Braid's, is the one that survived. Hypnosis is today an accepted clinical and experimental subject with a substantial literature, while animal magnetism is a chapter in a history book, and the difference between those two fates is almost entirely Braid's doing.