These three primitive tendencies and emotions, with their derivatives, form the first storey of the building. Fear and anger especially have an extremely general character; we can descend very low in the animal scale before we find them absent. The tender emotions, based on sympathy (the source of social and moral emotions), cover a much narrower area; they are, however, to be found among the lower animals under the form of temporary or permanent associations.
The other tendencies are slower in appearing, and their circle is more restricted: (4) The play-instinct, if we use this word to designate the tendency to expend superfluous activity. This is a stock which puts forth several branches: (a) the need of physical exercise; (b) the taste for a life of adventure; (c) the passion for gambling, which so soon becomes morbid; (d) æsthetic activity. (5) The tendency towards knowledge (curiosity) only appears with a certain degree of intelligence and attention; at first connected with the exercise of the senses (looking at an object, touching it, etc.), it is strictly practical, though at a later stage producing all the varieties of the intellectual sentiment. (6) At a later epoch, and perhaps in man alone, are manifested the egotistic tendencies (self-feeling, Selbstgefühl, amor proprius), which express the ego, the personality as conscious of itself, and show themselves in the emotion of pride, or its opposite, and their varieties. (7) There remains the latest in date (at least in man), the sex-instinct, of which the exceedingly general character is well known.
Such are the tendencies which, in my opinion, are the roots of all simple or compound emotions, present, past, or future. This assertion will be justified or invalidated by the following studies.
CHAPTER I
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.
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.