CHAPTER I. The Instinct of Conservation in Its

THE INSTINCT OF CONSERVATION IN ITS PHYSIOLOGICAL FORM.

Hypothesis regarding the relation between the nutritive organs and the brain—Perversion of the instincts relating to nutrition—Pathology of hunger and thirst—Proofs furnished of the priority of these tendencies in relation to pleasure and pain—Facts in support of this—Negative tendency; disgust—Its biological value as a protective instinct.

The above title may seem quite unconnected with psychology, or at least of a nature to throw little light on our subject. This is not the case. This group of tendencies—for we have seen that the conservative instinct is a sum, a total—represents the principal factors in what is called cœnæsthesia, the very soil on which emotional life grows and bears fruit. Moreover, the nutritive instincts have their pathology, which enables us to watch, not the genesis (which would be impossible) of new tendencies, but a radical transformation, a complete change of orientation, whose effects are easily observable and instructive. In a normal state the instincts are presented to us as ready made and in action; we cannot, either in ourselves or in others, go back to that distant and obscure period when the unconscious impulse, the blind tendency, showed itself for the first time, without antecedent experience of the pleasant or unpleasant consequences. So that our affirmation that tendency is antecedent to pleasure and pain may be stigmatised as merely theoretical so long as we are unable to cite indubitable facts in demonstration of it. These facts we are about to furnish.

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. 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.

Footnote 128:

Brugia, Patologia della cenestesia (1893).

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.

Footnote 129:

I must here repeat Briquet’s remark on this point: “However strange these appetites may appear, their origin can frequently be discovered. Thus a young woman, who would greedily devour the embers of her foot-warmer, told me that she had, from the beginning, been fond of the crust of bread; from this she came to like the crust of toasted bread, then charred bread, and so gradually acquired the taste for small pieces of charcoal. I am inclined to think that, were we to inquire into the origin of many of these strange tastes, we should find it as simple as the above.” Pierre Janet (État mental des hystériques, ii. p. 71) transcribes this passage, and adds, “I have often followed this advice and been in a position to appreciate its value.” This psychological inquiry is very ingenious, but only removes the difficulty a stage further back. It shows us through what series of associations the final result is attained; but association alone is not sufficient to arrive at this result, still less to render it permanent. It is only the external mechanism which explains, at the utmost, why the deviation should have taken this particular direction. Many persons are fond of crust, even of burnt crust, who will never come to have the slightest appetite for charcoal. Many have eaten charcoal out of curiosity, or by accident, but without acquiring a taste for it. It is some deeper and more powerful cause than association which lies at the root of these feelings and renders them active.

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.

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Footnote 130:

For details, see Campbell “On the Appetite in Insanity,” in the Journal of Mental Science, July 1886, pp. 193 et seq., and Belmondo, “Pervertimenti dell’istinto di nutrizione,” in Tamburini’s Rivista, 1888, pp. 1 et seq., where is cited the case of an insane patient in whose stomach were found 1841 objects, such as nails, bits of lead, and the like, weighing in all eleven (English) pounds, ten ounces.

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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.

II.

Nutrition—i.e., the essential act of physiological life—is safeguarded by two distinct kinds of tendencies. (I am still speaking of those only which come within the bounds of consciousness, and therefore have a psychological character.) On the one hand, we have the positive tendencies, consisting in an attraction towards and attack on the external world (in this case, food and drink)—viz., hunger and thirst. On the other hand, the negative tendencies consisting in aversion, refusal, flight, and summed up in the state known as disgust.

Disgust is due to excitement of the pneumogastric nerve, producing vomiting, nausea, or mere malaise. This repulsive instinct is connected (1) directly and immediately with taste and smell, two senses which can scarcely be isolated, and whose function is to watch over all substances entering the organism; (2) indirectly and through association of ideas with visual and tactile sensations (sticky, slimy bodies, etc.), by analogy and metaphorically with certain objects which have nothing in common with the nutritive functions—the ugly, the immoral, etc. In virtue of that law of transference or association of analogous sensations, of which we have spoken, the tendency departs more and more from its primary form; but in all cases there is a common groundwork of repulsion, refusal, desire to escape, etc.

Disgust under its primary form (the only one now occupying us) has not been much studied. Writers have contented themselves with classing it among organic sensations, while neglecting its emotional side, i.e., its function in the conservation of the individual. The only work I know on this subject is the excellent monograph of Ch. Richet, of which I here give a summary.

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Footnote 131:

“On the Causes of Disgust,” in L’Homme et l’Intelligence, pp. 41-84.

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Disgust is connected with conservation; it is “an instinctive feeling of protection.” In order to justify this statement, the author passes in review the various objects in nature, noting those which inspire us with disgust, and inquiring into the cause of this. The inorganic kingdom, in general, leaves us indifferent; yet sulphuretted hydrogen, ammonia, and various other gases cause a marked repulsion. This is the effect of an association of ideas; the smell recalls that of decomposition, of a corpse. As regards the vegetable kingdom, the herbivora, by reason of their diet, are the best subjects for observation; their instinct scarcely ever deceives them in the choice of food. We are reminded that, on their arrival in the New World, the Spaniards, hesitating before an unknown flora, whose properties were unknown to them, trusted the judgment of their horses. In man, Richet attributes the repellent influence exerted by bitter aromas to the fact that they frequently co-exist with toxic properties; he takes as types the vegetable alkaloids (quinine, nicotine, etc.), whose power as poisons is in some degree proportioned to their bitterness. So that we have always, at bottom, “the love of life and the horror of death.” In the animal kingdom disgust is aroused by putrescent matter, which indicates or suggests cadaveric decomposition and toxic substances; by parasites, by animals really venomous, or so reputed; for instinct, which sees everything in mass, confounds in the same repugnance the toad and the frog, the venomous serpent and the harmless snake.

In its general bearing, the thesis of the finality of disgust is incontestable. There are, no doubt, many exceptions, many facts difficult to explain (some have been pointed out by Richet); but if we take into account the complexity of the question, all objections fall to the ground.

That tastes are not to be argued about is a platitude which has been worn threadbare for centuries past. Taken literally, it would reduce disgust to a purely intellectual manifestation, with no biological bearing; it would deprive it of all specific character, and utterly eliminate it as an instinct. This, however, is a merely superficial position. Contradictions in taste may be compared with contradictions in morality. Variations in manners and customs, according to race, epoch, country, and even caste, do not exclude the existence of a law which has this characteristic common to all cases—that it is derived from the conditions of existence of each group, and is by that right imposed on it. In the same way, disgust exists everywhere, under one form or another, as a protective instinct. The question is complicated, in man, by his intellectual development, and the consequent modification, transformation, or even suppression of this instinct. Between reasoned knowledge and instinctive tendency a battle has been fought, in which the victory inclined sometimes to one side, sometimes to the other. We know the repugnance of animals towards a change of food. The same thing is seen in children, and in the inferior races, when not pressed by necessity. Plasticity grows with civilisation.

We may add to this the necessity for new adaptations; thus, in a besieged town, people devour unclean food; the instinct of physiological conservation is a “divided house,” where the positive form struggles against the negative with results, varying in different individuals. To this antagonism between primitive instinct and more complex rational motives let us add the influence of imitation and of fashion, and there will remain few or no unexplained exceptions.

As for the origin of this instinct, if we accept the hypothesis of acquired modifications, we may say that the animals and men best fitted for abstaining from hurtful substances, have ipso facto better chances of survival, and that they have been able to transmit to their descendants certain qualities which became fixed and organised as an innate tendency. Whether or not we admit this hypothesis does not matter, our only aim being to remind the reader that disgust is not a capricious and irrelevant phenomenon, but has its roots in the unconscious depths of our organisation.