Since, for the moment, we are eliminating movements in order to confine our attention to the _internal_ conditions of emotion, it is easy to see that these conditions reduce themselves to that which we designate by the name of internal, organic, vital sensations. This is not the place to enumerate the modifications of each in the case of each special emotion (for which the reader is referred to Part II.); the question, taken for the present in its generality, is put thus: Are the internal sensations reducible to a single and fundamental process? If the answer is in the affirmative, the internal conditions of emotion would find themselves simultaneously determined under their most general form. We can, at any rate, try.
The first difficulty consists in our not having a complete enumeration, on which all authors are agreed, of the internal sensations, as we have in the case of the special sensations. Beaunis gives a very detailed classification in eight groups; Kröner adopts a somewhat different one; both include pleasure, pain, and the emotions. Let us eliminate this last group (the affective manifestations) and confine ourselves to the vital sensations properly so called, connected with purely physiological needs, with the organs and functions indispensable to life: the different sensations of the alimentary canal (hunger, thirst, _malaise_, nausea, etc.); those of the respiratory apparatus (the need of fresh air, dyspnœa, asphyxia), of the circulatory apparatus, of the excretions and secretions; of the sexual organs in the normal state or in transitory phases (puberty, menstruation, pregnancy, menopause); the need of muscular movement, of rest, of sleep; the sensation of fatigue;—we have nearly all, if not all, the elements of cœnæsthesia, _i.e._, the consciousness of the body as living and acting.
Have these multiplied sensations a common cause? Are they different modes of one and the same process? Do they imply, at their origin, the same stimulus, the same kind of excitement, as all the varieties of visual sensations suppose luminous vibrations, and the varieties of auditive sensations, sonorous vibrations? Kröner maintains that, for all internal sensations, the initial excitation is of a _chemical_ nature. “Every organic sensation is based on a chemical process, and arises according to the laws of diffusion and osmosis.”[83] The author justifies his assertion by the enumeration of a large number of facts, for which I refer the reader to his book. Chemical action, according to him, either takes place under the gaseous form (a person passes from the open air into a room full of deleterious miasma) or under the liquid (alcohol, toxic substances in solution in the fluids of the organism and introduced into the circulatory current).
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Footnote 83:
Kröner, _Das körperliche Gefühl_ (Breslau, 1887), pp. 102-112.
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It is not very certain, _pace_ Kröner, that _all_ internal sensations are caused by chemical action, under one or other of the forms we have mentioned, and that their vague localisation is due to this cause alone, and not, as generally admitted, by their arising in organs incapable of movement. Thus tickling, giddiness, the muscular sensations (which Kröner and Beaunis include in this group) appear to depend on mechanical excitations rather than on chemical causes. At any rate, one cannot deny that the internal fundamental sensations—connected with nutrition and its immediate conditions, with fatigue and sleep, both of which result from a poisoning of the muscles and the nervous centres, with sexual life—are due to chemically caused excitations. This granted, we may go one step further in the track of James and Lange, and say that the emotions depend not only on physiological conditions, but still more intimately on the chemical action going on in the tissues and fluids of the organism.
In support of this extreme condition of the genesis of the emotions, we can only offer some fragmentary remarks, which, however, show how closely they depend on the variations of the intra-organic environment.
1. We have, in the first place, the group of exciting, tonic, depressing, toxic substances: wine and the various alcoholic beverages, haschisch, opium, coca, the aphrodisiacs, etc. Although they are artificial products, introduced from without, not engendered in and by the organism, we know how far they modify the interior environment, and consequently the temper, character, intensity, and direction of the passions.
2. But there are also the substances which the living body compounds or modifies for itself. It has been said that the organism is the receptacle and laboratory of poisons; in the state of emotion, the only one with which we are concerned at present, the function of this chemical process is manifested at every instant. We are always speaking of the weakening or the increase of the circulation of the blood; yet the emotional dispositions or modifications are connected, not only with variations of quantity, but also with those of _quality_ in the blood (anæmia, aglobulia, malarial poisoning, etc.). The popular expression regarding the emotions which “curdle the blood” is not so ridiculous as it might seem. Anger, fear, fatigue are often accompanied by changes in the intimate constitution of the sanguinary fluid. We may incidentally note the ascertained relations between certain cardiac affections and affective dispositions: in aortic affections, anæmia, excitement, irritability; in cases of mitral insufficiency, congestion, and a taciturn and melancholy humour. We shall elsewhere have occasion to enumerate the facts which show the correlation of certain emotions with toxic changes in the saliva and the lacteal secretion. Perspiration may, in certain affective states, be coloured red, yellow, green, or blue, not to mention the varieties of odour, which are assuredly of chemical origin. Even apart from mental disease, the urinary secretion could furnish a long list of chemical changes (azoturia, oxaluria, phosphaturia) coinciding with variations of the affective order, such as apprehension, melancholy, irritability. In gouty and rheumatic patients, the modifications of temper, depending much more on general nutrition than on active suffering, have often been pointed out. We know the relations between the secretion of the gastric juice and pleasurable or painful states; dyspeptics have a well-established reputation for being neither cheerful nor comfortable to live with. Beaumont ascertained, in the case of his famous Canadian, that under the influence of anger or other very strong emotions, the lining of the stomach was irritated, became red, dry, and very sensitive, and an attack of indigestion was the result. The rutting time (that of sexual excitement) is, in many animals, accompanied by deep-seated chemical changes, showing themselves externally by modifications of colour and odour, and, internally, not limited to the sexual organs, but extending to the whole of the body. It is known that the flesh of game is uneatable during this period, and that many fish, at spawning-time, become poisonous. It should not be forgotten that, during the same period, the animal becomes vicious, violent, aggressive, and dangerous. It would be easy to develop this point further, even as regards man (puberty, gestation, lactation, menstruation).
3. It has long been observed that, in the great majority of cases, mental disease begins by affective disturbances and that the intellectual aberrations only make their appearance later. Much more recently, a doctrine has been propounded which tends to seek the primary cause of these affective disturbances in a self-intoxication—_i.e._, in “the disorders produced in the interior of the organism by the excessive formation or the morbid retention of normal poisons; in particular, by those originating in the digestive canal and the urine.” Nutritive troubles through acceleration, retardation, or perversion, are assigned as the most general cause. In support of this, we are referred to the relations between melancholia, hypochondria, a pessimistic disposition, with hyperchlorhydria of the stomach, and the good results of purgative medicines; the numerous mental modifications coinciding with organic chemical modifications—_e.g._, certain attacks of mania in arthritic subjects. “One characteristic of the mental state of diabetic patients is the way in which the fluctuations of the mental state correspond with those of the sugar, and the barometric (if one may so call it) influence of the composition of the urine on the moral disposition.” This liquid, in mania, loses, to a great extent, its toxic character, in consequence of the morbid retention of normal poisons which are no longer eliminated.[84]
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Footnote 84:
Bouchard, _Leçons sur les auto-intoxications_; _Leçons sur les maladies par ralentissement de nutrition_. Régis, _Traité des maladies mentales_, pp. 112, 415, 423, etc. Féré, _Pathologie des émotions_, pp. 264, 495 _et seq._
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A long enumeration of facts bearing on this as yet insufficiently studied question would be here out of place. Besides, it could only be of real value if systematic—_i.e._, if under the heading of each emotion were grouped the physiological facts invariably accompanying it, and all the chemical modifications exclusively peculiar to it. We have only included the chemical conditions in our study, in order to penetrate as far as possible into the most general conditions of affective life, and show once more why it betrays the inmost constitution of the individual.
When treating of pleasure and pain, we remarked that they were too exclusively attributed to intensity of excitation (excessive, it was said, for pain; moderate, for pleasure), and that its _quality_ was forgotten. Since we have to do with hypotheses as to the part played by chemical conditions in affective life, since they are the most general, and since pleasure and pain also have this character of generality, it may be permitted to hazard a conjecture. This would consist in admitting that pleasure arises either when excitement increases chemical activity in the organism, without producing toxines, or when this augmentation of activity brings about the disintegration of the normal poisons; and that pain arises either when excitement creates an environment appropriate to the formation of toxines, or when, directly and at once, it promotes their formation, either generally or locally. But I would not insist on a simple _obiter dictum_, for which I can offer no proof, thrown out merely as a suggestion with regard to a question not as yet fully examined.
We have spoken throughout of the chemical modifications as coinciding with emotional changes. Are they effects or causes, or both, according to circumstances? It is clear that this question is not new to us. It is the antithesis between the psychological and physiological theories of emotion, presenting itself under another aspect; there is no occasion for discussing it a second time.
