"Hypnotism: the consensual management of the capacity for inductive reasoning." At least, that’s my definition of hypnotism. Let’s look at it bit by bit.
‘Consensual.’ Hypnotism is generally a one to one or one to many aspect of communication in which the parties have agreed to engage. It shares certain characteristics with brain washing and mind control (in the same way that the palliative provision of morphine shares certain characteristics with a junkie shooting horse) but differs, fundamentally, by being consensual.
‘Management.’ Hypnotism is not therapy, per se. It is the establishment, maintenance and dismantling (or, ‘management’) of a phenomenon conducive to the exercise of therapy.
‘Capacity for inductive reasoning.’ There are two main kinds of intellectual reasoning; inductive and deductive. Inductive reasoning enables us to conceive the big picture from it’s constituent elements. Deductive reasoning allows us to appreciate the constituent elements from the big picture. When a trance is induced a hypnotee is moved to a state of mind where their capacity for inductive reasoning can be suspended. Dave Elman, doyen of medical hypnotists, called this the ‘establishment of selective thinking’ (Findings in Hypnosis). The capacity for inductive reasoning can be suspended completely, in which case the hypnotee is left only with the ability to deduce. For both stage and clinical hypnotism, however, it is preferable that the hypnotee’s capacity for inductive reasoning is only suspended with regard to specific suggestions made by the hypnotist. Thus when a stage hypnotist tells his hypnotee that they are in love with a mop, they will be. They cannot inductively reason ‘it is a mop used for cleaning floors and generally I prefer to love women therefore I do not love this mop.’ They can only deduce all the behaviour which flows from their model of ‘love’ and express those behaviours accordingly. At the same time, however, they can hold a perfectly rational discussion about macro economics (or whatever) in which they can both induce and deduce normally.
So, hypnotism is the consensual management of the capacity for inductive reasoning.
Lots of people can get limb catalepsy, or ideo motor responses, and think they are doing hypnotism. Some people think eye closure equals hypnotism. It doesn’t. They may have achieved some kind of trance, but trance and hypnotism are not the same. As Elman says of his famous eye closure “But does that mean that you are hypnotized? Indeed, it does not. It is merely the entering wedge, and hypnosis is not obtained until selective thinking is firmly established.”
What Elman doesn’t say is what this establishment of selective thinking is exactly. Well, it’s the management of the capacity for inductive reasoning and when it’s done consensually, that’s hypnotism. When it’s done for therapeutic ends, it’s clinical hypnotism. When it’s done for entertainment, it’s stage hypnotism.
Of course, anyone can talk a good case. Doing it is something else. Here's a demonstration of me actually hypnotizing a someone.