HISTORY: A. HYPNOTIC STAGE The history of abnormal psychology can easily and definitely be divided into three stages : the hypnotic, the experimental and the analytical. The first two derived their inspiration from Paris, the third from Vienna. The beginnings of medical psychology are less than a century old. It is true that the material on which it was based, that of hypnotic experiences, is considerably older, but there was no psychological theory of it to begin with. In the 17th century Maxwell, and in the i8th Mesmer, made such extensive observations in this field that relatively little has been added to them since. They accounted for them by postulating the presence of a mysterious fluid of a magnetic nature which could be trans mitted from one person to another. Early in the 1 gth century mental conceptions, such as imagination, were invoked and a struggle ensued between what were called the fluidists and the ani mists. First to present the latter point of view comprehensively was Bertrand, in the early 'twenties, and it was independently de veloped by Braid of Manchester some 20 years later. It was Braid who first used the terms "suggestion" and "hypnotism"; his work put an end to the idea of magnetic fluid. In the eighties of the last century, however, the discussion was renewed in other terms. Charcot, the distinguished neurologist, revived the study of hyp notism, which had almost fallen into disrepute, and again at tempted to account for the phenomena by physiological explana tions. This was countered by Bernheim of Nancy, a pupil of a local doctor, Liebault, who practised hypnotism, and once more the animist school, which ascribed everything in the process to mental suggestion, triumphed.
The most striking feature of the observations made by em ploying hypnotism was that in the peculiar mental condition thus induced, hypnosis, a large number of phenomena occurred which, though evidently of mental origin, were of such a kind that can not be normally produced by the deliberate action of the conscious will, in short, of the mind as previously conceived. For instance, changes could be produced in the functioning of various bodily organs which have no connection with consciousness and some times even changes in the physical state of the body. A hyper acuity beyond the normal could be induced in the sense organs for ordinary stimuli, hallucinations of non-existent stimuli brought about and "negative hallucinations" that prevented the percep tion of existent stimuli. Of special interest in later developments was the extension of memory in hypnosis ; long forgotten and otherwise inaccessible memories could be recovered, so that one was led to suspect that perhaps no memory traces are ever obliterated. These memories could be retained or not in the sub ject's subsequent waking state at the hypnotist's will, so that from these and many similar observations the conclusion was forced on psychologists that consciousness was by no means an essential attribute of mental processes. It could also be proved by post hypnotic suggestion that mental processes of which the subject was in no way conscious could lead to definite effects in conduct, so that it would not be true to regard them as merely latent.
It was at that time observed, notably by Charcot, that many of the phenomena that could be brought about in hypnosis, e.g., paralyses, contractures, anaesthesias, blindness, etc., were identical with spontaneous symptoms of a particular disorder, hysteria. He inferred that hypnosis was an artificially created hysteria, a conclusion which, though subsequently abandoned by psycho pathologists, may yet contain a germ of truth. It was only much later that the relationship between the two conditions was elu cidated through the discovery that hysterical symptoms, includ ing the bodily ones, are directly produced by unconscious mental processes and, further, that they are related to post-hypnotic suggestions in being closely connected with "delayed" obedience to parental influence that has been incorporated—largely uncon sciously—into the personality.
The theory of all these phenomena was slow in developing. For half a century no perceptible progress was made on the idea thrown out by Durand (1855, 186o) that a clear distinction should be effected between the "ideoplastic" and "hypotaxic" phenom ena. By the former he meant all those results of implanted ideas briefly indicated above, by the latter the peculiar mental state of the subject that made them possible. The essence of this state had long been recognized to be the existence of a peculiar rapport between the subject and the hypnotist. This is an emotional re lationship of intense concentration which may at times reach the pitch of rendering the subject oblivious to the presence and deaf to the voice of any other human being. In r9o5 Freud's investi gations led to the conclusion, subsequently amplified by Ferenczi and Ernest Jones, that the nature of the hypnotic rapport was a particular kind of erotic relationship of which the subject was quite unaware and, further, that its peculiar potency was due to a reanimation in the subject's unconscious mind of an infantile de pendence on the parents.
b. Experimental Stage The second stage in the development of medical psychology was the experimental work undertaken in the eighties of the last century by Binet, Fere, and, above all, Janet. By a series of beau tifully devised experiments Janet was able to demonstrate con vincingly the presence of mental processes, which he called "sub conscious," of which the subject was quite unaware. It could be shown, for example, that this subconscious part of the mind was able to register and reproduce impressions on an anaesthetic limb when no stimuli applied to it could be detected by con sciousness. The subject could feel and could not feel with the same limb, a paradox only to be described in terms of mental dissociation. The same conclusion was reached from study of more complicated mental manifestations, extensive amnesias, (gaps in memory), alternating personality, fugues (flights) and so on. Janet was able to describe a large number of hysterical symptoms in terms of mental dissociation and the problem was thus shifted to the nature and origin of this. The only explana tion he was able to throw out was the assumption of a congenital tendency to dissociation, a constitutional defect in mental inte gration to be correlated with what he termed a fall in psychical tension, a condition favoured by such factors as fatigue, shock, distress, grief, harmful suggestions, etc.
The various forms of what are grouped together as cases of dissociated personality, which have been most exhaustively studied by Morton Prince, introduce another problem. They include al ternating personality, double or multiple personality, hysterical fugues with amnesia, hypnotic somnambulism and the like. The actual problem of personality in this connection will be dealt with later, but it is necessary here to consider a feature of certain cases for the light it throws on the limitations of the conceptions just mentioned. In many of the cases it is found that of the total store of available memories one "personality" has access to all, whereas another has access to only a portion. The dissociation in question, therefore, cannot be a complete break, for it is travers able in one direction though not in the other. It is what Bernard Hart has termed an out-of-gear relationship. The noteworthy point is that all the memories concerned are accessible to one form or another of consciousness. Further they are all of a kind familiar to ordinary waking life. When a subject realizes that a part of him has been feeling sensations in an anaesthetic hand, or when a patient who has lost his memory for the past month is told that during this time he performed such and such actions, he may be astonished but he does not find it incredible. The mental processes not available to the main stream of conscious ness are for this reason termed "subconscious," and it is essential to appreciate the all-important distinction between this concep tion and that of the "unconscious," for the processes comprising the latter are alien to any form of consciousness the subject may possess and contemplation of them is repudiated with incredulity.
The origin of these was the communication, in 1884, by an older colleague, Breuer, of an observation the latter had made with a patient some three years previously. It was to the effect that if the memories connected with the beginning of an hysterical symptom could be recovered in hypnosis the symptom in question would vanish, in other words, that there was an inherent connec tion between the presence of such symptoms and the forgetting of certain significant mental processes. After spending a few years at other work Freud pursued the train of investigation thus sug gested and soon confirmed Breuer's observation. He was imbued with a deep faith in scientific determinism as applied to mental phenomena, and did not disdain to act on it even in regard to apparently trivial and meaningless phenomena which would usually be explained as being due to "chance." The object of the investigation was essentially a genetic one, and this feature has characterized all his later work, being, indeed, identical with the one just mentioned. Being forced to recognize the limitations of hypnotism as a method of investigation, Freud was led to devise one without its deficiencies, and in so doing made the most f ar reaching of all his discoveries. This was what is known as the free association method, which opened the way to the exploration of the deeper layers of the mind. The essence of it is that the more the conscious guiding of a train of thought is abrogated, the more extensively is it guided by processes of which the subject is un aware. The material thus produced provided either open or dis guised indications of these unconscious processes. They have to be extracted from it by an interpretative procedure and the criti cism naturally arises of the necessarily subjective nature of this. It is claimed that sufficient safeguards are provided in the tech nique of the procedure, which is a very complicated one, to check any tendency to subjectivity. In particular the observer has first to become aware, through self-analysis, of his own unconscious processes so as to obviate the automatic temptation to bias on the one hand and to blindness on the other.
An essential part of the technique consists of the correct handling of two groups of reactions which Freud terms "trans ference" and "resistance" respectively. By the former is meant the tendency of the subject to allow his unconscious trends to emerge only in the form of personal references to the analyst. Various ideas, attitudes, phantasies and emotions appear in this form, but prove on investigation to have been transferred tempo rarily to the analyst from some other person of importance in the subject's previous life. The discovery of these earlier atti tudes is thus regularly made via the person of the analyst. By resistance Freud refers to the innumerable forms of opposition that are automatically manifested whenever the subject is near ing some important unconscious material. The interpretation of the material in connection with these reactions is usually easier than might perhaps seem and it is constantly confirmed by the memories subsequently recovered and by the general piecing to gether of the material in the later course of the analysis. It is maintained that the converging nature of this admits of no alternative conclusions to the ones reached in the course of the interpretative procedure and that any errors in the latter are soon disclosed by the subsequent material.