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Chapter 11

A Further Explanation Of The Activity
Of The Sensuous Instinct

416. We have to return now to the promised explanation of the more complicated activities of the sensuous instinct (cf. 401). This is undoubtedly a formidable task, and we are well aware of the difficulties we shall encounter.
The most serious difficulty becomes obvious when we consider that the explanation of the more complicated activities of the sensuous instinct has to be given without reference to intelligence and will. This is the first condition for any satisfactory explanation, although as far as I am aware it is not adhered to by those investigating the cause of animal activities. Normally, authors arbitrarily attribute some role to intelligence and will even in animals and, in doing so, eliminate the major difficulties encountered in positing the true cause of animal phenomena. In my opinion this is a very serious mistake. The concept of brute animal (which is the contrary of rational animal) totally excludes the light of reason together with all cognition and, consequently, every aspect of will (which, as a power operating according to what is already known, presupposes cognition).

417. The difficulty experienced in explaining the activities of animal sensuous instinct begins, therefore, with the first step in the investigation, that is, the formation of a correct concept of animal itself. As human beings, we use our intelligence to carry out many of the activities done by animals without intelligence. Hence, we can scarcely conceive mentally of a being entirely enclosed within the limitations of corporeal feeling and the instinctive activity which is the spontaneous effect of feeling.

418. In undertaking this difficult task, let us, therefore, first carefully examine the conditions required to explain satisfactorily the marvels of animal activity.

We see immediately that animal activities are not casual, disordered movements. Although taking place at various levels of complexity, these movements harmonise in an extraordinary manner and tend towards some purpose. A suitable and satisfactory explanation of these activities must therefore take into account: 1. the way in which such movements can originate from feelings; 2. the way in which the animal, without any trace of intelligence, can produce such suitably ordered movements for a given aim. The explanation of animal activity involves, therefore, two questions: How does motion arise? How does this motion attain a purpose? Both questions must be answered without reference to intelligence and will. If these conditions are not respected, the phenomena of sensuous instinct cannot be explained.

419. The first of our two questions has partly been dealt with (cf. 394-400). As we said, the stimulus producing the sensation by irritating the nerves is also the cause of incipient movements in the nerves themselves. These initial movements draw the sensuous principle into action and this in turn, by prolonging its action spontaneously, propagates and develops these extremely delicate movements throughout larger parts of the body. In my opinion, the initial movement of the nerves occasioned by a sensation is the general principle underlying every movement produced by the sensuous instinct .

The first feeling is the fundamental feeling. The movements permanently connected with the fundamental feeling are vital movements such as circulation. This is not sufficient, however, to explain spontaneous, partial movement in animals which, according to the principle laid down, requires a modification of the fundamental feeling, that is a new, acquired feeling, as we have called it.

The animal would remain perpetually immobile relative to these new, spontaneous movements if there were no new modification affecting the nervous system. This modification, which does not have its cause in the animal sense itself, must be a principle foreign to the animal and of such a kind that it produces new nerve movements parallel to the new feelings. Consequently the first cause of the instinctive movements we are considering cannot come from the animal itself; it must come from elsewhere. There is no necessity for supposing that the animal moves itself, which would certainly require the use of some kind of will. A sufficient explanation will be found in an excitatory stimulus foreign to the animal.

When animal activity has been brought into action through this foreign impulse or stimulus, it continues to act through the law of inertia, of which we have spoken. Far more is needed to explain cessation of action already present in the animal than would be required to explain how it continues in action.

420. We must now consider the law governing the propagation of spontaneous movement. In propagating itself, this movement increases through a harmonious alternation of feeling and movement. Let us imagine a local sensation. This produces nervous tremors, or some kind of extremely delicate movements in the affected nerve. In turn, these movements arouse and excite the soul to sensation which the soul spontaneously seconds and develops. This spontaneous action of the soul immediately gives rise to further propagation of the tiny movements. The laws of movement then insure that the parts moved by the soul come into forceful contact with adjacent or contiguous parts and through mechanical laws cause them to move. This produces new stimulation for the soul which is now drawn to apply its spontaneity to these movements. In this way, the material impulse given to the parts near those already moved by the soul comes back to the soul as more and more parts are aroused and in turn make themselves felt. The minimal, hidden, imperceptible movements gradually develop, spread out and multiply.

Let us take a war-horse as an example. As soon as it hears the sound of the trumpet, the horse begins to tremble all over, even if it has never been in battle. If it is an experienced war-horse, its movements are accentuated. Obviously we can distinguish the local sensation of sound from the general movement coursing through the animal. The first movement aroused by the sound in the acoustic organ is definitely minimal. The spontaneity of the soul, stimulated by the rapid, frequent movements of the nerves governing hearing, immediately renders the movement spontaneous and amplifies them in a marvellous way. The reinforced movements then act forcefully upon the adjacent parts surrounding them, while these, having received movement mechanically, act upon the soul either by drawing or forcing it into further action. The soul, which cannot withstand the new pressure put upon it, frees itself from strain by seconding the movements it receives. These then become spontaneous, and lose all oppressive tendencies. This in turn maintains movement, which would otherwise soon cease, and indeed extends it throughout the parts. By degrees, but with extreme rapidity, both movement and agitation is generated throughout the horse which responds with all the alertness required for battle.

421. It seems likely that every local feeling gives rise in some way to this kind of propagation of sense and movement. In all probability it is also at the origin of that obscure, but extremely efficacious feeling (which we called alimentary, cf. 408-411) constantly accompanying the local sensation of taste.

Tracing the propagation of local feeling throughout the whole animal would provide a very rewarding field for highly skilled investigation. Each of the more obvious feelings would have to be studied individually. For example, a given scent pleases some and displeases others. The local sense and the scent are the same, but the feeling diffused by the scent - and usually inadverted to - is very different. This causes it to be pleasing to some, but not to others. The qualities of the diffused feeling are widely different, and too refined to be easily noticeable, but in a hidden way are very effective. They dispose the animal for different experiences and incline it in different ways. A pain, for example, will render one person reflective, others sad or joyful, or affected in similar ways even independently of the association of ideas.

422. An equally delicate field for research, connected with that already suggested, would be to follow the propagation of the minimal nerve movements dependent upon the stimulation and movement of the various local interior or exterior senses. The aim would be to determine the progress of movement from different starting points in the nervous system, and explain how the final movement was propagated in perfect harmony with the nature of the minimal movements received in the stimulated nerve.

For example, the researcher could try to explain why multiple, varied movements, rather than a single movement, are produced by sound, as we see in the case of the war horse. Because sound depends upon a certain number of air waves, the movements received by the acoustic organ (movements which cannot be reduced to a single movement) vary in an orderly way according to the different impulses of air. A tremor, and perhaps a contraction, is produced in the horse. The nerves, vibrated by frequent movements, must cause the varied, agitated and frequent movements in the animal. Movements dependent upon rhythmic sound will give rise to dancing, by retaining and reproducing on a larger scale the wonderful order already invisibly present in the first nerve movements.

423. Let me make an observation on the feeling and effects of ticklishness, a phenomenon which perhaps has not yet been properly explained. Tickling begins with the stimulation of many tiny, multi-directional movements in the cutaneous organ. We should keep in mind what was said about the spontaneity of the soul which, on feeling some movement in a part of the body, co-operates in the movement spontaneously in order to free itself of pressure that it would otherwise be unable to sustain. Given the innumerable, tiny, conflicting movements, the soul must be in a state of great agitation as it strives to follow them and make them all spontaneous. New movements, taking place before the soul has time to respond to the previous stimuli, would give rise to contrasting activities and motions, and to convulsive movements (which are truly contrasting movements) first expressed in laughter, and then widely propagated. It is not improbable that these mutually opposed movements found in tickling, and generally in convulsions, could be sufficient to kill a person. Nor is there any doubt that the special constitution of the cutaneous organ, in which the most delicate nerve endings are to be found, plays a great part in this strange, complicated phenomenon.

424. The same kind of research into the propagation of movements arising from nerve disturbance simultaneous with feeling should be applied to the problem of `shared feeling' (or `sympathy'). Doctors use this phenomenon to indicate the extension of pain or disease in widely spaced parts of the human body, but it is not known if the phenomenon is founded in the anatomical connection of the nerves and muscles, or whether the life and sensuous instincts of the soul have some part in it, as would in fact seem certain. As we know, the unity and continuity of the soul permit it to act of its own power simultaneously in places distant from one another.

425. But undertaking such research would take us too far from the scope of this book. For our purposes it is sufficient to have indicated and demonstrated the general principle according to which the soul exploits feeling in order to impart movement to the muscles. We should note, however, that what has been said is valid for all feelings, internal and external. Consequently, we should apply the principle of spontaneous movement to phantasy images, which also give rise to movements in the way we have described. This would explain why a war-horse already accustomed to battle would be more daring under the direction of its rider than a horse which had not experienced the din of war.

426. What has been said explains the origin of movement from feeling, and the development and propagation of movement from minimum to maximum. But the propagation of movement must finally reach a limit beyond which harmony and spontaneous action ceases in the soul. Our explanation would seem insufficient, therefore, to explain cases in which the duration of movement appears to transcend this limit as, for example, when an animal in its eagerness to prolong some pleasure continues to act.

It seems to me that this persistence in continuing pleasurable activity has to be sought in the animal's synthetic or unitive power which in its simplicity joins the animal's act with the pleasure it receives from this act. Just as the animal naturally remains in a pleasurable state, so it perseveres with its act which, associated with pleasure, becomes a single thing for the soul perceiving this unity.

427. The soul's unitive power must also be the origin of the animal's effort to reinforce its act as it strives to reproduce and strengthen the degree of pleasure it receives. Experience reveals to the animal, which is directed by its apprehension of the whole scale of degrees of intensity, that its pleasure increases according to the intensity of effort that it devotes to its act. This apprehension in the animal generates sensuous expectation of something similar in the future - and it does indeed seem that the animal connects the past with the future in this way. In other words, the animal's successive experience is re-presented in its sense-faculty as `something unified', from which arises the sensuous expectation already mentioned as the cause of continued movement and of the reiterated action the soul puts into movement. The sense-faculty itself achieves this synthesis of feelings, by joining within its own unity 1. both the action which produces and the pleasure which accompanies movement; and 2. the successive degrees of intensity of movement which it feels actively, and the growing intensity of pleasure, which it feels passively. And even this multiple apprehension is an incitement to further movements. It is an animal affection, the basis and principle of constantly growing movement through which the animal maintains itself in spontaneous movement towards pleasure.

428. This affection, the total effect of all the animal's feelings, cannot be one of the particular feelings which serve to make up the affection and act as its source. It is a unique affection springing up from all these feelings; it entirely dominates the animal as the animal moves and contributes to the continuation and increase of its own pleasurable movement. A good example of this can be seen in the baby's way of feeding at the mother's breast.

First, the baby feels the act by which its lips strain on the nipple. This act, although composed of simultaneous movements of fauces, lungs and other parts of the body, is a single, very simple act for the baby whose partial efforts and movements are unified by means of the animal unitive power. The result in the baby is a single, simple, internal action. Along with the feeling of its activity, the baby has pleasant feelings arising from the flow of milk into its body and from the nourishment it receives. This, too, is made into a single feeling by the unity of the animal although it can be analysed into as many partial feelings as there are parts renewed by the feed, and nerves stimulated by pleasure.

The animal's unitive power, which has made a single, internal, original action of the many external actions, and a single, internal, final feeling of the many external feelings, now apprehends in a single, very simple act both the active feeling of its internal, universal action and the passive feeling of its internal, universal pleasure. As a result, the animal finally possesses in the depths of its being a single feeling (active and passive) of these two complex feelings. This final apprehension and feeling, the deepest of all feelings, informs the animal essence, and provides the principle of instinctive movement which, although simple in itself, extends its effects to several powers. Various parts are then moved simultaneously by a single thrust or pressure or slight internal movement. Each part or power, according to its own nature, receives and shares in the movement to the extent of the impulse given by the animal element to its internal parts, which are the first to participate in the stimulus arising from the unification and final completion of so many simultaneous feelings in the single feeling just described.

In the same way, the movements of the act of sucking, of which the animal element has an active feeling, and the pleasurable sensations of the milk in the body, are prolonged and repeated as they succeed one another with varying degrees of intensity. This gradual succession of actively felt movements and of passive feelings is also unified internally by the animal unitive force which makes of the succession a single (active-passive) feeling and apprehension. The animal element, either by continuing or reinforcing the movement, perseveres with this single apprehension as long as pleasure lasts. In other words, it continues what it has begun, and according to its experience gradually adds to it. In this way, time (as something feelable, not as a concept), although successive externally, is simplified in internal animal apprehension. A single internal feeling extends to embrace an entire succession; from that single feeling, movement expands in a simple act to produce a whole succession and progression of multiple acts [App., no. 7].

429. This whole artifact of feelable nature is necessary if the baby is simply to carry out the apparently easy task of feeding at the breast. One defect in the activities of the unitive force, however, would be sufficient to impede proper feeding. We would have to say that the difficulty in breast-feeding experienced by the cases of mentally defective children in Switzerland depends upon some defect in the unitive force. This would also account for their general difficulty and imperfection relative to first needs. When ten years old, these children are still incapable of putting food in their mouths and chewing it, so that they have to be subject to forced feeding.

430. The two preceding articles have clarified the origin of animal movements, which require neither a rational nor a volitive principle. We saw that animal spontaneity is aroused by two causes: 1. the need felt by the animal to avoid any painful state such as that of resistance or inaction in one of its living members when this is moved; 2. the tendency the animal feels to prolong and enhance any state of pleasure experienced in some determined activity.

Whichever of the two causes is operative, the principle of movement depends upon animal passivity which arouses itself to movement only through the intervention of some outside cause or impulse. This passivity then stimulates spontaneous activity in the animal. But once aroused, spontaneous activity continues and itself becomes a cause of new movement. In turn this movement becomes a stimulus to spontaneity, and a circular operation, combined with increasing interchange of movement and stimulus, takes effect. This explains the growth and endurance of animal movements.

The first of the two causes (by which the soul seconds the nerve movements) explains directly how the underlying spontaneous movement begins; the second (by which the soul perseveres in pleasurable action) provides a particular explanation for the expansion and continuation of movement.

But all this is not sufficient to explain the phenomena of the sensuous instinct. As we have said, it is not enough to indicate how movements can manifest themselves in the animal. We have to go further and show why these animal movements arise with such order, harmony and cohesion that they obtain some useful purpose for the animal itself. These movements are so far-seeing and wise that we are almost persuaded of their direction by some extraordinary intelligence. Perhaps this is the greatest difficulty in explaining adequately the functions of the sensuous instinct. Certainly, it is a field of philosophy still quite unexplored by mankind.
This does not discourage us, however, but provides greater impetus as we find ourselves in such fruitful, uncultivated territory. And we can hope for greater understanding and indulgence from the learned in this area where even to attempt such a beautiful, but arduous task, calls for sympathy.

431. First, I need to describe my approach to the problem. I do not believe that the order noted in the various movements of the sensuous instinct depends upon any light of reason in the animal, nor that it can be explained by positing a single cause. This order springs from three distinct principles which, taken together, can only show how the wonderful order, present in each and every complex animal operation, is generated.

The first principle by which animal movements attain such order must be found, I think, in the natural order of external stimuli and their consequent actions which incite the animal and produce in it the first movements.

The second principle positing order in animal movements must be sought in the construction and cohesion of the animal body which is characterised in all its parts with exquisite harmony and pre-established concord amongst its movements as they work to the advantage of the animal itself.

Finally, the third principle necessary for the order in animal operations is the nature of the spontaneous activity of the animal itself.

432. Therefore:

1st. There is something foreign to the animal which originates its movements. This consists in the natural or artificial stimuli which cause sensations and movements in the animal.

2nd. There is something in the animal body which orders the animal's movements. This is the harmony of forces and parts making up the body.

3rd. There is also something in the soul itself of the animal which orders and governs animal functions.

All three causes of order in animal operations have the wisdom of the Creator as their primary source. He imposes order upon all things - an order in inanimate matter, an order in the living body and a more wonderful order again in the feeling, animating principle, that is, the soul.
We have to speak about all three principles or causes of order. But we must preface our remarks with a comment.

433. As we have seen, the movements under discussion are always a consequence and effect of preceding feelings. If order is present in the movements, it has to be found previously in the feelings. As a result, we have to say that if the three causes of order put order in our movements, as we have indicated, they also posit it first in the feelings. We shall see this as we discuss each cause in turn.

434. We hinted at this cause when we showed that the order arising in dancing depends upon the order of sounds aroused in the acoustic organ. In turn, the order of the sounds depends upon the order of air waves which strike and stimulate that organ (cf. 396-400, 422-424). The same could be said about almost all animal movements. They always have an order of succession relative to the time in which they are distributed.

All natural stimuli at work in the animal follow certain immutable laws: day succeeds night; the seasons follow one another continually; each day brings an almost regular series of degrees of temperature, of atmospheric qualities, or wind direction, of electrical conditions in surrounding bodies, of cycles to which the animal body is itself subject. The supremely wise Author of nature has harmonised everything so that each has its role in bestowing a certain order on animal movements.

Even the animal body, accustomed to producing movements at appropriate times, offers well-ordered stimuli to itself and other animals living with it. The animal, finding this order satisfying, perseveres in it because the order is advantageous and pleasurable; disorder is odious, and avoided by instinct.

435. The wonderful harmony found between the different parts and forces constituting and activating the animal body also has a role in establishing order. The parts and forces of a body combine so well that a given feeling must be accompanied by a definite movement (simple or complex) extremely useful to the animal itself. Let us consider a few facts illustrating this harmony.

If we obstruct an animal's breathing by tying something around its neck, the animal is immediately stimulated by instinct to use its paws in an effort to remove the restriction; if we secure an animal by the leg, and impede its freedom of movement, the animal tries to bite through the rope. A blindfolded dog has no peace until it succeeds in shaking off the blindfold. Animals instinctively lick a wound or a sore; irritation induces scratching. At teething a baby compresses and rubs its gums with its fingers and other bodies to ease the arrival of the new teeth, and so on.

There is no doubt that these and many other facts depend upon a single principle determining the animal to such well-ordered and useful actions. And we shall see later the significant part played in this by spontaneity and especially by the animal's unitive power. In the meantime, it is easy to see that animal spontaneity is considerably aided in its operation by the harmony according to which each organ works to the advantage of the others.

436. It is the physiologists' task to determine the amount of influence exerted in this way. I think, however, that their investigations and experiments will finally produce the following result: `Where an organ is injured or impeded in its function, the other organs join in a series of movements directed towards the distressed organ. These movements are stimulated by the local pain, suitably affecting the nerve-endings and eventually the entire nervous system.' Such united movements are founded, I maintain, in the distribution of the material forces used by the life principle to help the animal's well-being. This movement, at once material and vital, is then perfected by the sensuous instinct for which the first material and life movements have to serve as a common stimulus. These operations, therefore, have a specific place: first, the dispositions of the material forces posit an element of order in the functions; another element is then added by the life instinct; finally, a third element, which subsumes and perfects the first two, is derived from the sensuous instinct.

437. This final cause, drawing the various animal movements to act advantageously for the animal, could also be illustrated by reference to lesions affecting different parts of the animal, and by observing the laws according to which the lesions remove or disturb the harmony already established by the wisdom of the Creator of animate being.

438. The order existing between the parts of the body (mechanical harmony), and between its forces (dynamic harmony), protect the animal against lesions and disturbance by simultaneously stimulating and directing the movements of the two instincts. But it also assists the animal's well-being in numerous other ways.

If the nose were not situated near the mouth, or did not possess a strict relationship and continuity with the palate and oesophagus, animals could scarcely be directed in their choice of healthy foods by smell. The association of the two senses of taste and smell explain many facts which at first sight could make us believe that animals, in their choice of food, were furnished with extraordinary intelligence. The association of these two senses is considerably assisted by their nearness to one another. This proximity depends only upon the wisdom of the Creator in connecting the parts of the animal which have to help one another mutually.

When one bird sings, all sing. And in general animals reply to sounds that they hear. We imagine, perhaps, that they are speaking to one another. It is clear that these phenomena would never take place if the vocal organs were not situated near the acoustic organs, or at least if they did not have some connection with one another. The connection and proximity of nerves causes the air which strikes and disturbs the acoustic nerves to initiate simultaneously movements of the nerves and muscles affecting the voice. Indeed, the movements of the acoustic nerve stimulate and start corresponding movements in the vocal organs - movements completed by the spontaneity to which they give rise and from which the voice proceeds.

The preludes to generative action are due to the physical, dynamic connection between the generative apparatus and the nerves of the eye and touch, their various movements and corresponding image-phantasies.
In a word, every single animal function, however wonderful and complicated, depends in great part on the order present in the arrangement of the body. This order necessarily results in variously ordered and extremely wise animal actions without our needing to presuppose intelligence of any sort in the animal.

439. Finally, the nature of the animal's very own spontaneous activity is the third, chief principle giving rise to the order of operations of the sensuous instinct which appear to depend upon reason.
Animal spontaneity has its own determined properties, and is subject to fixed laws. As a result, its operations naturally bear the mark, as it were, of these properties and laws, and of the regularity and marvellous order dependent upon them.

The properties and laws of spontaneous animal activity are profound, and would require lengthy study even for a tentative development. I shall confine myself, therefore, simply to mentioning them sufficiently for an adequate understanding of our present work.

440. The laws of spontaneous animal activity are principally derived from three sources:

1st. From the condition of the organic body to which spontaneous activity is tied in its operations. - The laws deriving from this source are highly mysterious; and effective work on them will have been achieved (even though they remain unexplained) when they are accurately described, and their existence is well established by factual observation.

2nd. From the inertia to which the spontaneity of the sense-instinct is subject.

3rd. Finally, from the synthetic or unitive force of the animal.

441. The soul, because of its adhesion to the organic body, is subject to many extraordinary laws. In particular, its spontaneous operations proceed with the same degree of regularity as that manifested in the state of its body.

We have already noted that the more perfect animals are twofold, that is, composed of duplicated parts, more or less equal, at least relative to the principal organs of feeling. Moreover, the greater the conformity between both parts, the more distinct and perfect the animal's feelings. In the same way, perfect imagination depends to a large extent on equality between the two hemispheres of the brain. An injury to one, or even inequality between them, causes confusion and disturbance of the judgment which of course depends upon material provided by judgments associated with cerebral movements. But if inequality in the brain hemispheres, say, causes defective images, it is clear that equality between the hemispheres leads on the other hand to regularity in the operations of the soul.(197) The same can be said about any lesion in the brain or in the nerves. The nature itself of the complex being formed by body and soul, and the nature itself of the union, conceal a law according to which the operations of the soul are determined in one way rather than another. A reason explaining order lies in this law.

442. But the laws to which the soul's activity is subject as a result of the action it receives from corporeal nature differ in their depth and wonder. Some are of the utmost delicacy. For example, let me remind the reader of the phenomenon of residuary colours. If I fix my eye for some time on a red object, and then suddenly look at something black, I see a bluish-green tint in it. If instead I first look at something orange, my eye then sees purple where the black is. If the pupil is affected by something greenish-yellow, the impression becomes violet when we place ourselves in darkness. On the other hand, if the eye has looked for some time at bluish-green and is then placed in the dark, it sees red. Likewise, purple looked at intensely is changed into orange in the eye, and violet into greenish-yellow.

Moreover, if the eye has been fixed for a long time on something white, and is then plunged into total darkness, the white sensation changes after a short period into different colours until it vanishes. First, the white sensation changes to yellow, then to red, purple, blue and finally green, when it disappears. Such a phenomenon shows clearly that the optic nerve is engaged in an action which changes in determined ways. To each of these changes corresponds a different sensation in the soul.

Now it is obvious that there must be a natural order amongst the colours themselves, that is, an order founded in the physical nature of the sensations if there is: 1. a stable law according to which movement (the condition of the retina affected by light) changes; and 2. another law according to which the soul modifies the action it posits in receiving the sensation of colours.

But colours are feelings and, as we said, where there is order in feelings, there must be order in movements deriving from them. The action of the feeling soul, relative both to the life instinct and to the sensuous instinct, receives a determined order from the profound, hidden laws resulting from the union of soul and body.

It may indeed be impossible for us to offer a principle, or first reason, to explain the source of these laws, but it is sufficient to have verified them carefully through experience and observation of the facts. Who can say why the nature of things is what it is? Does not this nature depend in the end on the eternal, intrinsic order of being?

443. The activity of the feeling soul is also regulated and ordered in its operations by laws arising from inertia. It is scarcely necessary for me to say that by inertia I understand the soul's disposition for remaining in a given state, or for persevering with a given action until an exterior cause makes it change state or action.

444. Both inertia and spontaneity are present in the soul. The latter tempers the former. Inertia maintains the soul in the same action until a foreign cause produces change; spontaneity provides the soul with an aptitude for changing its state or action, without resistance on the part of the soul, as soon as a foreign cause moves the soul.

445. Matter is inert and lacking in spontaneity. Hence it resists any force wishing to change its state of rest to one of motion, or its state of motion to one of rest, or to change a state of lesser motion into one of greater motion, and vice versa.
The feeling soul, which is simultaneously endowed with inertia and spontaneity needs on the one hand some exterior cause to induce it to change state. On the other hand, if this cause is present, it gently follows its invitation without resistance.

As we said, this arises because the first act of the soul's life instinct(198) operates continually upon the body (cf. 371-384). In this initial act, the soul possesses an impulse towards all future movements. The impulse, however, remains undetermined to any particular movement. Consequently, it does not move; it lacks a sufficient reason determining it to one rather than another movement. The universal impulse to all movements and all directions involves an equilibrium impeding movement in any specific direction.

Hence the causes drawing the soul to move the members of the body do not, properly speaking, provide the soul with motion, as happens in matter, but only with some determination towards motion. As a result, the soul is said to cause movement spontaneously, although we also attribute to it inertia in so far as it needs an external cause to determine it.

446. With these clarifications in mind, we see that inertia provides certain laws regulating and ordering the instinctive movements of the soul.

The two principal laws are:

1st. The soul determines itself to those movements which give it most natural pleasure.

2nd. The soul determines itself to and prefers, other things being equal, those movements which it can perform more easily.

The first law appertains to the soul's feeling, the second to its activity. Both correspond to the two causes we have already assigned to spontaneous movement, that is, the need to avoid disturbance, and to pursue pleasure (cf. 426-429).

447. Careful analysis shows that these laws are mutually inclusive: it must naturally be more pleasurable for the soul to do what is easier, and easier to do what is more pleasurable. But I have made two propositions of this one law because pleasure is sometimes found towards the end of an act, and effort at the beginning. Moreover, ease and pleasure can be considered from different points of view, and thus become the sources of more particular laws about the soul's activity. But we have no time to enumerate these laws here.

448. We note only that pleasure and ease are qualities sought by the soul of its very nature. They are rooted in the soul's inertia and spontaneity. Spontaneity tends towards what is pleasurable; inertia towards what is easy.

449. It is clear that these two laws must posit some order in the animal's instinctive movements. One result of the laws is that the soul is moved to choose whatever is easiest and most pleasurable; it does not operate by chance, nor is it indifferent to a choice of movements. We might almost say that its choice is made intelligently, although this is not the case. It is guided only by the laws of inertia and spontaneity.

We cannot wonder, therefore, if every animal carries out the movements most suitable to its nature. For example, most animals walk on four feet; human beings walk upright because this is easier and more pleasant for them. Every animal has its own habits and its own ways of lying down, stretching, taking food to its mouth, eating and drinking and carrying out other natural activities. In each action, animals prefer what is most natural, and therefore easier and more pleasurable for them.

450. We have to consider that an animal which feels any need whatsoever - hunger or thirst are the obvious examples - also experiences some kind of disquiet. The need produces tiny, unrelieved, multi-directional movements. Amongst these movements, the animal finds some which are suitable for satisfying its need and bettering its state. It follows these indications and gradually finds itself feeling better as it removes the cause of its distress. Put something on a dog's back, for example, and you will see the animal take up whatever position it finds suitable for removing the burden. If it discovers that lowering its back provides the freedom it desires, it will finally sit down and remove the weight altogether.

More often than not, animal instinct is very quick in choosing the movements and actions required for attaining the most comfortable and pleasurable position, for removing discomfort, and for bettering its state. Sometimes, however, a certain amount of effort and experiment is needed. The child, for example, spends much time finding its balance and directing its muscles in such a way that they help it walk and keep it walking. This is a case where the most comfortable and pleasurable position is tiring at the beginning, and requires effort for success.

451. Animals, therefore, can be trained, and would seem capable of grasping the art of movement and action, although this in fact depends entirely on the modification of instinct and on the sensuous retentive faculty accompanying instinct.(199)

Everything can be explained easily enough by reflecting that the sensuous instinct moves the animal to direct itself towards the easiest and most pleasurable movements and positions, and that every need experienced by the animal arouses in it, as we said, a multitude of tiny movements. These give rise to discomfort, and the animal, according to the laws we have detailed, pursues and develops whatever movements it finds easiest for attaining most satisfaction from the feeling it experiences.
The reader will see immediately how profound a source of stupendous order this is for instinctive animal movements.

452. Other extremely beautiful laws can be discovered by observing all that renders certain movements easy and pleasurable to a determined species of animal. It is also possible to explain why certain things, disposed in a given way, seem ordered harmoniously, while others do not. Such an investigation will succeed in establishing the principle of a natural passage in animal movements and feelings, that is to say, of the existence of certain steps determined by nature, making the passage from one determined feeling or movement easier and more pleasurable than the passage to any other feeling or movement. Only natural steps enable a passage to be made smoothly; effort is required to make the passage where nature has placed neither stepping stones nor signposts. In other words, there is a law, based in animal nature and sensitivity, which renders the passage from one state to another, or from one feeling to another, either smooth and delightful or difficult and distasteful. Granted this, it is certain that everything leading the animal to experience a series of feelings and movements ordered according to the steps decreed by nature will be extremely pleasurable and harmonious. Ignoring nature's way of passing from one state to another means losing this pleasure and harmony.

453. Rameau's splendid observations on sound, and Giambattista Venturi's on colours can be used to illustrate this point.
Rameau noted that as a sound dies in the ears it gives a sensation of a twelfth, that is, of a fifth above the octave. This shows that the natural passage for the sensations of the acoustic organ is from first to fifth. Playing a fifth after hearing the first interval, therefore, finds the ear already naturally inclined and disposed for what it hears. This is the obvious reason for the delight found naturally in a jump of a fifth, and the same is true for every other chord, as Rameau shows. We can see, therefore, that harmony of sounds is founded in the hidden laws of the union between soul and body, and in the principle of the sensuous instinct which, by reason of inertia, always seeks to enjoy what is easiest and most natural.

Our own G. B. Venturi noticed that the same occurred relative to residuary colours. Red harmonises well with green because the pupil, before losing its red sensation, passes naturally to green. Orange and purple, violet and yellow also form harmonious associations, as Mengs observed, and in general imaginary colours harmonise with the true colours that precede them. The sensation of one colour disposes the soul to pass so naturally to the sensation of another colour that the second sensation, once determined, not only costs the soul no effort, but helps it to carry out what it would have done of itself, although less vividly.

454. Something similar may take place in other sensations, but it is more difficult to observe.
However, the facts we have indicated are sufficient to show that there is a principle of order and harmony in the very nature of the sensitivity resulting from the union of soul and body. This principle must have an incredible influence on the movements proceeding from sense.

Notes

(197) Dr. Miraglia, in a paper read to the medical section of the 7th Italian Congress (Naples, 1845) maintained: `If the action of an entire hemisphere, or part of it, is altered, the exercise of all the functions is necessarily disturbed; but if the action, either of the entire hemisphere or part of it, is annihilated, activity is concentrated in the other hemisphere' (Cf. Polto, Relazione dei lavori, ecc., t. 53, 54).

(198) Our life instinct corresponds exactly to Hippocrates' enormon.

(199) Darwin and others decided to deny the presence of instinct, pointing out that animals learn certain activities. But what they call learning is not true, human, intellectual learning. Instinct is not just a faculty initially determined in its acts so that it has to do everything in the same way from the first moments of the animal's existence. Instinct, like other capacities, depends for its operation on many circumstances. In the first place, it needs stimuli and external occasions in order to act. As these vary, the instinctive activity also varies. Moreover, instinct also needs phantasms and the sensuous retentive faculty. The phantasy is the animal's means of carrying out actions when objects are lacking. The dog searching for its master is one example; imitating what it sees is another. Finally, habit provides another law of animal activity which has immense influence on instinct. What we normally call animal learning, therefore, is only the acquisition by the instinct of certain modifications and new attitudes dependent upon three main causes: 1. the stimulation of the exterior senses; 2. phantasms, together with their mutual associations and relationships with sensations; 3. the force of habit. Nevertheless, these three causes presuppose the existence in the animal of the instinctive principle which is then modified and, as it were, educated by them.