From a Western point of view, the decisive moment in the history of hypnosis occurred in the 18th Century (coinciding with the Enlightenment and the Age of Reason).The work of Franz Mesmer, amongst others, can be seen as both the last flourish of “occult” hypnosis and the first flourish of the “scientific” viewpoint.
On the other hand, it’s only in the last few decades that we’ve come to realise that!
Hypnosis itself hasn’t changed for millennia, but our understanding of it and our ability to control it has changed quite profoundly.
The popular image of the hypnotist as a charismatic and mystical figure can be firmly dated to this time.
Inevitably, these magical trappings led to Mesmer’s downfall, and for a long time, hypnotism was a dangerous interest to have for anybody looking for a mainstream career.
At the same time, the style of hypnosis changed, from a direct instruction issued by an authoritarian figure (a legacy of the charismatic mesmerist) to a more indirect and permissive style of trance induction, based on subtly persuasive language patterns.
This was largely due to the work of therapists such as Milton H. More importantly, perhaps, hypnosis became increasingly practical, and regarded as a useful tool for easing psychological distress and bringing about profound change in a variety of situations. Advances in neurological science and brain imaging, together with the work of British psychologists Joe Griffin and Ivan Tyrrell who linked hypnosis to the Rapid Eye Movement (REM), have also helped to resolve the “state/non-state” debate, bringing hypnosis and hypnotic trance firmly into the realm of everyday experience.
The history of hypnosis, then, is really the history of this change in perception.
In the 21st century, there are still those who see hypnosis as some form of occult power.
At the same time, the nature of “ordinary” consciousness is better understood as a series of trance states that we go into and out of all the time.