Instinct and the Unconscious. W.H.R.Rivers
of shock or illness. Hypnotism furnishes a striking example of the process by which experience is suppressed. By means of suggestion given in the hypnotic state any experience, pleasant or painful, which occurs during this state may be banished from the memory. When this has been done the hypnotised person is quite unable to recall the experience, and it will remain unconscious until he is again hypnotised or until the experience is recalled under some other condition in which unconscious suppressed experience comes to the surface. In this case the suppression takes place independently of the will of the hypnotised person, but there is reason to believe that the suggestion to forget is more likely to be successful, the more the forgetting is in consonance with the conscious wishes of the subject. This probably gives the clue to the fact that conscious repression seems often to lead to suppression. The suppression itself is unwitting, but the wish of the sufferer for suppression assists the process, or at least helps in its maintenance and completeness.
I have now to consider a characteristic of active forgetting and suppression which is of great importance in understanding its nature. The experience which tends to be forgotten or repressed is the immediately painful. If we forget an appointment or a letter in connection with which we anticipate unpleasant emotions, the ultimate consequences may be even more unpleasant than the immediate experience from which we escape by the act of forgetting. If we were able to consider rationally the consequences [p. 21] of the lapse, we should find that in most cases the I course which would give us least trouble and inconvenience is the long run would be to keep the appointment or write the letter. The process of active forgetting, however, takes no account of these ultimate consequences, but is directed exclusively towards the avoidance of the more immediate pains and discomforts. The same seems to be true of cases of pathological suppression. If, as I suppose, the claustrophobia of my patient was the result of the suppression of his four-year-old experience, there can be little doubt that the sum-total of unhappiness due to his dreads was far greater than that which would have resulted from the immediate memories of his terror when in the passage with the dog. The memory was suppressed because of its immediately painful character, and in following this course Nature took no account of the effects of the suppression which were to torment the child and man for thirty years. The suppressions which form so large an element in the neuroses of war we also directed to allow escape from the immediately unpleasant, regardless of future consequences. Suppression is a process of reaction to the pleasures and pains which are immediately present, and takes no account of the more extended experience with which it is the function of intelligence to deal.
Footnotes
[1] See Appendix I.
[2] The Psychopathology of Everyday Life.
IV. Suppression and Inhibition
The examples of the unconscious and of its instrument, suppression, which have been given in the last two chapters, have been taken from aspects of experience which belong clearly to the domain of psychology, and involve mental processes of a relatively high order. I propose now to consider the relation between the suppression of psychological experience and certain physiological processes. I will begin with an example drawn from the borderland between the psychological and the physiological, one dealing with the sensory concomitants of nervous process in a case of experimental interference with the integrity of the nervous system.
Observations on the sensory changes which accompany the regeneration of a divided and reunited nerve have led Head and his colleagues to distinguish two different kinds of mechanism on the afferent side of the nervous system.[1] Prolonged observations after the division of nerves in Head's own arm brought out clearly the existence of two definite stages in the return of sensibility. In one of these, the protopathic stage, the sensations are vague and crude in character, with absence of any exactness in discrimination or localisation and with a pronounced feeling-tone, usually on the unpleasant side, tending to lead immediately, as if reflexly, to such movements as would withdraw the stimulated part from contact with any object to which the sensory changes are due. At this stage of the healing of the reunited nerve there are present none of those characters of sensation by which we recognise the nature of an object in contact with the body. The sensations are such as would enable one to know [p. 23] that something is there and that it is pleasant or unpleasant. It is also possible to distinguish between mere contact or pressure and stimulation by heat or cold, but within each of these modes of sensation there is no power of distinguishing differences in intensity nor of telling with any exactness the spot where the processes underlying the sensory changes are in action.
The second stage of the process of regeneration is characterised by the return of those features of normal cutaneous sensibility, such as exact discrimination and localisation, by means of which it becomes possible to perceive the nature of an object in contact with the skin and adjust behaviour according to this perception. The modes of reaction which make this exactness of discrimination and power of external projection possible are grouped together under the heading of epicritic sensibility. In interpreting these observations two chief possibilities are open. Epicritic sensibility may be only a greater perfection of protopathic sensibility, experience gradually enabling an exactness of discrimination and localisation which were not at first possible. The other alternative is that the two kinds of sensibility represent two distinct stages in the development of the afferent nervous system. According to this second view the special conditions of the experiment revealed in the individual two widely different stages in the evolution of cutaneous sensibility. Many features of the experiment point strongly to the truth of the second of these alternatives. The way in which epicritic sensibility returns and the fact that it is possible to annul it by treatment affecting only the peripheral factors, without influence on such central processes as would be set up by experience,[2] go far to show that the two modes of sensibility represent two stages in phylogenetic development.
All that we know of the protopathic stage is consistent with its being the representative of the sensibility of an animal which possesses only the power of becoming aware of changes of a crude kind and, according as these changes are pleasant or unpleasant, of reacting at once by such mass-movements as would take it nearer to, or remove it from, the source of the stimulation. If [p. 24] there is only capacity for such mass-movements, there will be no necessity for the discrimination which would enable the exact perception of the nature of the object. There would be a definite correlation between the crude nature of the sensibility and the limited capacity for behaviour possessed by the animal.
Epicritic sensibility, on the other hand, is adapted to behaviour of a far more complex and delicate kind. The sensations do not merely tell the animal or man that something is there and set up the crude mass-movements of approach or withdrawal, but they enable the many forms of reaction which become possible when the exact nature of the stimulating object is recognised.
It is not necessary for my present purpose to consider these two possibilities fully. Whatever be the interpretation of the two stages, there is no doubt as to their existence, and my present object is to point out certain special features of the relation between the two. When epicritic sensibility returns, the earlier protopathic sensibility does not persist unaltered side by side with the later development, but undergoes certain definite modifications. Some of its elements persist and combine with elements of the epicritic stage to form features of normal cutaneous sensibility. Thus, the cold and heat of the protopathic stage blend with the modes of temperature sensibility proper to the epicritic stage, and form the graded series of temperature sensations which we are normally able to discriminate. The crude touch of the protopathic system blends with the more delicate epicritic sensibility of this kind, while protopathic pain, with its peculiarly uncomfortable rather than acute quality, forms a much larger element in the normal sensibility to pain. In this process of blending or fusion certain aspects of the earlier forms of sensibility are modified to a greater or less extent, and in some cases this modification involves the disappearance of certain characters. This disappearance