I.
The nutritive acts take place in the inmost recesses of the tissues and organs. By what channels are they connected with the cortex, either when undergoing its influence or transmitting the echoes of their slackening, accelerative, and other modifications? On this point physiologists know little. According to some (Schiff, Brown-Séquard), there are relations between the digestive tube and the optic layer, the striated body, the cerebral peduncles; the psychic actions which modify respiration being transmitted through the third ventricle and the anterior corpora quadrigemina. The experiments of Pitres and François-Franck on the sensori-motor zone of the cortex show that excitement, at any given point, results in: augmentation, retardation, or even arrest of breathing; acceleration of the cardiac rhythm, and, if powerful, inhibition or even syncope; vaso-motor effects, a contraction or relaxation of the bladder; an influence on uterine contractions; on the secretion of the saliva and the pancreatic juice, and on trophic action in general. According to Goltz, the destruction of the anterior lobes produces atrophy, that of the posterior the contrary effect. These discrepancies and uncertainties are to us of small importance; but it remains certain that the nutritive functions especially depend on the pneumogastric and the great sympathetic nerves, that they are in some manner represented in the cerebral cortex and form the principal contents of cœnæsthesia. Though in the adult they play only a latent and intermittent part by reason of the preponderance of external sensations, images, and ideas, it is probable that in animals, particularly in voracious ones, the functions are inverted, and that cœnæsthesia, as a synthesis of the organic functions, passes to the front rank. This has even been asserted to be the case in children and savages, the argument being based on the fact that they have, in proportion, larger stomachs and longer intestines, and on various other characteristics.[[128]] However this may be, when deep-seated disturbances take place in the organism, cœnæsthesia is modified; which involves modification of the tendencies, and, consequently, of the position of pleasure and pain.
The facts I am about to enumerate relate to nutritive needs only; but we shall find their equivalents or analogies in the other manifestations of emotional life. We can, therefore, already generalise so far as to say that when abnormal or morbid tendencies, however absurd or violent, show themselves, their satisfaction involves pleasure, their non-satisfaction, pain. Where the normal man, with normal tendencies, places pleasure, the abnormal man, with abnormal tendencies, places pain. Conversely, that which the man with normal tendencies feels to be agreeable, the man with abnormal tendencies feels to be unpleasant. Pleasure and pain follow the changes of tendency, as the shadow follows the movements of the body.
Let us look at the facts. We have at this moment to do only with the perversion of instincts relative to nutrition.
Pregnancy produces during the first few months digestive, circulatory, secretory disturbances, incomplete nutrition, and at the same time those grotesque aberrations of appetite, those depraved tastes, which every one knows, and of which the catalogue would be endless. Not to digress from the subject of this chapter, I say nothing of those morbid tendencies of another kind which show themselves at the same time in some women—homicidal or suicidal tendencies, aversion to husband, kleptomania, etc.
In anæmic, chlorotic, hysteric, and other subjects, if badly nourished, we sometimes find an acute pleasure in earth, straw, tobacco, chalk, sand, charcoal, etc., and an aversion to the most savoury foods.[[129]]
There are many instances of hypochondriacs searching for and devouring with enjoyment worms, toads, spiders, caterpillars, etc.; and the beginning of insanity is often marked by an eccentric and disordered dietary.
Again, at a still lower stage, we have coprophagy and scatophagy (the swallowing of excrements, urine, the contents of spittoons, etc.), which are rarely, if ever, found in any but idiots and those suffering from dementia, i.e., in beings whose simplest instincts have been abolished or perverted. The voracity of certain idiots has been attributed to paralysis of the gastric branch of the vagus nerve.[[130]]
The same would apply to the sense of smell, so intimately associated with that of taste that it has justly been called “tasting at a distance.” (We must not, moreover, forget its close connection with the sex-instinct.) Certain persons, who cannot endure the most delicate aromas, enjoy the odour of valerian, of asafœtida, and of still more repulsive substances.
To sum up, we may say that, in a given race, at a given moment of its development, there is a certain average of alimentary tastes, whose satisfaction is pleasurable; but on the appearance of deep-seated disturbances in the organism everything is changed, tendencies, desires, and aversions; the pleasurable and painful states, which are merely effects, vary with and in the same manner as their cause.
The physiological acts, which have for their aim the maintenance of nutrition, scarcely enter into the consciousness, except under the guise of hunger and thirst, whose psychology cannot be studied here, because it forms part of another department—that of the sensations. All the phenomena previously enumerated are reducible to anomalies or deviations of hunger. The pathology of thirst is simpler, for it may be summed up as dipsomania, a condition whose modalities and clinical varieties have no interest as regards the psychology of instinct; but so far as this need is concerned, the transformation of the normal and natural tendency into a morbid one does not differ in its mechanism and results from what we have already stated in the case of hunger.
There exist, in general and special treatises, many descriptions of dipsomania to which we may refer the reader. Leaving aside all hallucinations, motor disturbances, intellectual and moral decadence, we shall only consider the genesis, the development, and the consolidation of this morbid tendency.
“It is not every one who can be a dipsomaniac.” To drink too much, whether voluntarily or by accident, is a thing which may happen to any one; but such an occurrence does not necessarily bear the fatal and inexorable character of an insatiable instinct. The period of incubation—i.e., of gradual action tending towards complete metamorphosis—presents clearly-marked psychological characteristics, showing a disturbed state of cœnæsthesia and belonging to the region of the emotions: malaise, sadness, lack of energy and courage, apathy, moral insensibility, vague presentiments of danger. After this the eruption takes place in the form of an intense, devouring thirst. Many try to react on this and cheat themselves by the aid of water or mucilaginous substances, which shows, as several writers on the subject have remarked, that alcoholism properly so called is only a paroxysm: under the pressure of a progressively intensified craving the decisive step is taken. We shall find a great variety in the numerous observations published on this subject, a struggle at the beginning only, a struggle preceding every attack, indignation of the patient against himself, under the influence of which he calls himself names, and forces himself to swallow strange and repugnant beverages; all these phenomena are found in various cases. To sum up, the history of this psychological metamorphosis is briefly this: incubation, formation of a fixed idea, obsession, final fall.
It is scarcely necessary to point out once more that the primary fact is the transformation of a natural tendency, in consequence of changes in the organism, and that satisfaction and appeasement only come afterwards.