Much of what is written about consciousness seems to assume the existence of a "normal" or baseline state of awareness. The contents of consciousness are supposed to display themselves against a more or less standardized mental background. At most, perhaps, there will be some discussion of dreaming to act as a counterpoint to waking normality. Yet we know that this is really a considerable over-simplification; we have reports of numerous other possible kinds of awareness: mystical, ecstatic, near-death, drug-induced, toxic confusional, post-traumatic, manic and melancholic, to name just a few. Many psychologists and philosophers, notably William James, have recognized the importance of such unusual states for theories of mind and have tried to take them into account. This is particularly true of hypnotism, probably the exceptional mental state most widely studied by Western researchers in the last 200 years. Many have believed that it provides a uniquely valuable window into the mind and especially the "unconscious", yet the literature of hypnotism is notoriously difficult to evaluate. The publication of Alan Gauld's new book is therefore to be welcomed. Gauld is particularly well qualified to write a study of hypnotism; an academic psychologist with a long-standing interest in the history of hypnotism, he has previously written excellent books on the founders of the Society for Psychical Research and on mediumship among other subjects. He is thus not afraid to take on contentious subjects, to which he brings a scholarly mind, objectivity, and a pleasantly dry wit.
One of the main ways in which hypnotism is relevant to questions of consciousness is in its apparent ability to produce psychological automatisms, in which during or after hypnosis apparently purposeful activities are carried out without the participation of the subject's ordinary awareness. There are important resemblances here to abnormal mental states such as fugue and multiple personality disorder, in which two, three, or more different personalities seem to alternate with one another, with varying degrees of inter-personality access to common memories and awareness. Multiple personality has attracted a lot of interest recently, especially in North America. But sceptics suggest that most if not all such cases are iatrogenic, produced by over-zealous psychiatrists. Hypnotic phenomena, similarly, are often dismissed as role-playing, and the existence of a special "hypnotic state" is disputed.
What, then, are we to think about the hypnotic state? Is it a definable entity? Are there perhaps numerous altered states of consciousness that go by that name? If there is a hypnotic state, is it the same as somnambulism? Such questions have been debated for over 200 years, beginning soon after the alleged discovery of "animal magnetism" by Anton Mesmer. Whether Mesmerism was identical with what we now call hypnotism is uncertain; Mesmer's treatment methods were highly theatrical and Mesmer himself had some of the qualities of a shaman. It was in any case not Mesmer but one of his followers, the Marquis de Puységur, who discovered the "trance". Reports began to appear of paranormal phenomena: subjects allegedly became telepathic or clairvoyant and even made diagnoses and proposed treatment while in trance, both for themselves and for others.
Later in the nineteenth century Mesmerism fell out of favour, at least in scientific circles, attention shifting to what we now call hypnotism. Treatment of disease by this means continued, but there was also a vogue for performing ambitious surgery under hypnosis. The discovery of chemical anaesthesia led to the abandonment of hypnotic analgesia (though it is still sometimes used today), but hypnotism continued to be studied and theorized about by neurologists, especially in France, where rival theories were developed by JM Charcot and his followers in Paris and by AA Liebault and H Bernheim in Nancy. Charcot linked hypnotism with hysteria, and therefore regarded it as a pathological state, whereas the Nancy school held that almost all hypnotic phenomena could be obtained in normal individuals. This view eventually prevailed and the use of hypnotism as a means of therapy became increasingly widespread in Europe and America. In Paris, however, Pierre Janet continued to regard hypnosis as hysterical somnambulism, and after a period of eclipse his ideas are once more being taken up by some researchers today. One of the merits of Gauld's historical approach is that it shows how supposedly modern explanations of hypnotism have in reality been advanced before. Such a survey "may discourage one from propounding ideas which, as so often happens in this field, are revived cyclically by persons seemingly unaware of the previous cycles".
The authenticity of hypnotic phenomena in general is a central question. Gauld's own position is moderately sceptical. He doubts that there is a state characterized by unsuggested post-hypnotic amnesia and state-dependent memory; he thinks rather that "hypnosis" is a socially transmitted concept system. Ideas of hypnosis have become almost institutionalized in our society; hypnotic subjects behave as they do because that is what is expected of them.
"The mysterious domain of hypnosis emerges…as a kind of fairy palace, less than real, but more than illusion. It has, one might say, sufficient substance in its foundations to have deceived mortals rather well. Especially has it ensnared savants of past generations, who in turn have misled the media and the public at large. But from our vantage point at the end of the twentieth century we can begin to see that there is no one path by which it may be reached, no one material of which it is built, no one hidden chamber containing all its secrets, no one key which will open all its doors, and no simple formula by which it may be dispelled. Those who set out to investigate it should beware of the bafflements to come."
Gauld's scholarly yet readable book is an excellent starting point for anyone who wishes to embark on such an enterprise.