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OF THE SENSES, THE APPETITES, AND THE INSTINCTS.
The Sensations.-I. Muscular sense -2. Sight and Touch-3. Instinct,
germ of Will.
EVERY study of experimental psychology, whose object is the exact description of facts, and research into their laws, must henceforth set out with a physiological exposition, that of the nervous system. Mr. Bain has done this, and also Mr. Herbert Spencer (in his latest edition of the Principles of Psychology). This is the obligatory point of departure, not resulting from a passing fashion, but from nature itself, because the existence of a nervous system being the condition of psychological life, we must return to the source, and show how the phenomena of mental activity graft themselves upon the more general manifestations of physical life. Mr. Bain describes the brain, the cerebellum, the marrow, the spinal cord, and the spinal and cerebral nerves. The nervous force acts upon these different portions of the body after the manner of a current.
• It is nevertheless manifest that the nervous power is generated from the action of the nutriment supplied to the body, and is therefore of the class of forces having a common origin, and capable of being mutually transmitted,—including mechanical momentum, heat, electricity, magnetism, and chemical decomposition. The power that animates the human frame and keeps alive the currents of brain, has its origin in the grand primal source of reviving power, the sun.'i
If our means of observation and of measurement were perfect, we could see how nourishment is consumed in the human being, one part being attributed to the animal heat, another to the action of the viscera, another to the activity of the brain, and so on. The nervous force which thus results from the expenditure of a given quantity of nourishment may be converted into every other form of animal life.
Hence we must conclude, contrary to the received opinion,
1 Bain's Senses and the Intellect, edit. 1855, p. 59.
that the brain alone does not constitute the sensorium, that it is not the only seat of the mind ;'but that that seat is wherever there are nervous currents, including the brain, the nerves, the muscles, the organs of the senses, and the viscera.
From this completely physiological beginning we pass on to the first class of phenomena properly belonging to mind. This is not, as it might at first be supposed, the study of our various sensations. There are more general phenomena, hitherto neglected by psychology, which the author describes and examines with that wealth of details, that abundance of facts, which characterize true experimental study.
These are the phenomena of spontaneous activity, known to us by muscular sense. This sense, whose objects are sensations attached to the movements of the body, or to the action of the muscles, must not be confounded with the five ordinary senses; it is generally admitted that it ought to be studied separately.
The chapter which the author devotes to this subject affords a specimen of his learned and scrupulous method. Always in search of experiences, bent on obtaining completeness, he illustrates by his fine and ingenious remarks a great number of curious and common facts which metaphysics, looking down upon them from its height, does not seem to have observed. I cannot, however, attempt to analyse his minute analyses.
We generally see in our own activity, interpreted by our movements and our desires, the result of some anterior sensation or knowledge ; but prior to the former, there is a spontaneous activity coming from ourselves-coming from within, and no' from without, which acts of itself, and not by reaction against the exterior world. The facts which best establish the existence of this is the tonicity of the muscles, the state of permanent closing of the sphincter muscles, the morbid activity and excitement which it causes, the extreme mobility of childhood, and of second childhood, which can only be explained by a surplus of activity. This spontaneity, to which psychology is apparently indifferent, nevertheless contains, as we shall see, the germ of the development of the will.
Muscular sensation, although it very nearly approaches sensa
tion properly so called, differs from it in this, that the one is associated with an internal stimulus, the other with an external stimulus. United to the organic condition of the muscles, it reveals to us the pains and the pleasures which result from exercise, the different modes of tension of the organs in movement; and it gives the measure of the effort.
We might perhaps especially call it the sense of our movements, and of that which relates to them.
The muscular sensations have a double character, affective or emotional, and intellectual; each in an inverse ratio to the other.1
In considering these under their emotional aspect we find two great classes of movement, whence very different muscular sensations result. Slow movements induce sleep; they produce calm after morbid agitation ; they inspire gravity and sad
After day of exertion and tumult we recover tranquillity by the sympathetic effect of measured movements, such as music and the conversation of calm persons. Thence also the slow pronunciation in exercises of devotion-the melancholy sounds of the organ. Quick movement, on the contrary, causes great excitement of the nerves. These rapid movements are in fact a sort of mechanical intoxication. Every organ in a state of rapid motion communicates its excitement to all the other organs in motion. If we walk quickly, still more if we run, the mental tone is excited, our gestures and speech become hurried.
As examples of this class of muscular excitement and movement, we may cite hunting, dancing, the orgie-like worships of the East, and the rites sacred to Dionysus and Demeter. Finally, muscular sensation may be given to us simply by effort, and independently of all movement; for example, carrying a weight, sustaining one's body, are cases of dead tension.
Considered under their intellectual aspect, the muscular sensations are very important from the point of view of knowledge. If to a weight' of four pounds held in the hand we add another
It is a psychological law that in a complex phenomenon like a sensation, knowledge is clear and complete in proportion as pleasure and pain have been slight, and vice versa.
pound, the state of consciousness changes : this change of constitution is discrimination, or the faculty of discerning, and it is the foundation of our intelligence. Let us note this definition of our author ; later on we shall discover its import.
The different modifications of muscular action make us know three things : first, resistance, which is the fundamental experience ; secondly, continuation of effort, accompanied by movement or not; finally, rapidity of contraction of the muscle corresponding to the rapidity of the movement of the organ. We have only to reflect a little in order to see that these are important notions, whence several others are derived. Thus the degree of effort or of force expended gives not only the measure of resistance, but the inertia, the weight, and the mechanical properties of matter. The continuation of muscular action gives ideas of duration and extent.
“The difference between six inches and eighteen inches is expressed to us by the different degrees of contraction of some one group of muscles, those for example that flex the arm, or in walking, those that flex or extend the lower limb.'1
Finally, the knowledge which we have of the degree of rapidity of our movements permits us to estimate the speed of other bodies in motion, the measure being at first borrowed from our own movements.
We will now pass on to the study of sensations. They are distributed into six classes : sensations of organic life, of taste, of smell, of touch, of hearing, and of sight. The three latter are especially intellectual. Mr. Bain gives the pre-eminence to sight, and even places hearing above touch. His analysis, ample and detailed as it always is, is largely indebted to chemistry and psychology. We shall confine ourselves to selecting three essential points in this study, which are treated with originality and depth : the nature of organic sense, the perception of the exterior world by touch, and by sight.
Even in France we begin to consider the sensations of organic
Bain, Senses and Intellect, p. 114.
life as a separate group.? Spread over the whole body, particularly in the viscera, they have no organs proper to themselves. Their obscure and continuous action exercises an incontestable influence over our psychological life. Distinct from muscular sensations which especially reveal to us the movement and the effort of the muscles, they reveal themselves to us by the pleasure or the pain which they cause us; they are most frequently affective. Mr. Bain particularizes seven species.
The sensations due to the condition of the muscles, the pain experienced by their being cut, the suffering caused by excessive fatigue, broken bones, torn ligaments; in a word, all the violent damage which can be done to the muscular system.
The nervous system is not only the instrument proper to the faculty of feeling, it also has organic sensations resulting from the condition of its tissue ; for instance, neuralgia, nervous exhaustion, and tic-douloureux are examples of pain proceeding from the tissue itself.
Circulation and respiration, with the sensations of hunger, thirst, and suffocation, which belong to them, the pleasure of breathing pure air, the uneasiness produced by a confined atmosphere, have considerable influence upon our condition.
The state of consciousness which results from a healthy circulation
be considered as the characteristic sensation of animal existence.
Digestion, like respiration, presents all the conditions of a sense ; an external object, nourishment, and a special organ, the alimentary canal. To it we owe the agreeable sensations produced by a good condition of the digestive organs, the malignant influence exercised by their deranged condition, the sensations of nausea and disgust, and the melancholy caused by diseases of the stomach and intestines. We may
add the sensations of cold and of heat, their influence upon the activity of the organic functions; and, finally, the sen
1 See in particular M. A. Lemoine, L'Ame et le Corps, and M. L. Peisse La Médecine et les Médecins. The sensations, says the latter, proper to headache, indigestion, and palpitation prevent our being ignorant of where our organs are, apart from the aid of dissection.