diamond CONTAINING WITH NOTES BY THE TRANSLATOR. IN TEN VOLUMES. VOL. V. London PRINTED FOR THE PROPRIETOR, SOLD AND BY H. D. SYMONDS, PATERNOSTER-ROW. 1807. T. Gillet, Printer, Wild-Court
As all our knowledge turns upon the relations by which one object differs from another, if there existed no brute animals, the nature of the human being would be still more incomprehensible. Having considered man in himself, ought we not to derive every assistance, by comparing him with the other parts of the animal creation? We will proceed then to examine the nature of animals, to compare their organization, to study their general economy, thereby to make particular applications, to mark resemblances, to reconcile the differences; and from the assemblage of those combinations, to distinguish the principal effects of the living mechanism, and to make a further progress in that important knowledge of which man is the object. We will begin by reducing within its proper limits a subject which, at first view, appears to be immense. The properties of matter which animals possess in common with inanimate beings come not within our present consideration, and which we have already fully treated upon. For the same reason we shall reject such qualities as are found equally to belong to the vegetable and to the animal. As in the class of animals we comprehend a number of animated beings, whose organization is highly different from that of man, as well as from more perfect animals, so we shall wave the consideration of them, and confine ourselves to those animals which have evidently the greatest affinity to us. But as the nature of man is superior to that of animals, so of that superiority we shall study to demonstrate the cause, in order that we may distinguish what is peculiar to man, from what belongs to him in common with other animals. Previous to an examination of the minute parts of the animal machine, and their peculiar functions, let us view the general result of this mechanism, and, without at first reasoning upon causes, confine ourselves to an elucidation and description of effects. An animal has two modes of existence; that of motion, or awake, and rest, or asleep; and which, while life lasts, succeed each other alternately. In the former, all the springs of the machine are in action; in the latter, there is only a part of them so, and this part acts as well while the animal is asleep as while it is awake, and is therefore absolutely necessary since the animal cannot exist without it. It is also independent of the other, as it acts of itself; the former, on the contrary, depends on the latter, as it cannot exercise itself alone. The one is a fundamental part of the animal economy, since it acts continually and without interruption; the other is less essential, since it acts but by internals. The first division of the animal economy appears general and well founded. An animal when asleep is more easy to be examined than when awake and in motion. This difference is essential, and not a simple change of situation as in an inanimate body, which may be equally and indifferently at rest or in motion; for in either of these states it would perpetually remain, unless constrained to quit it by some external power or resistance. By its own powers the animal changes its condition; and naturally, and without constraint, it passes from repose to action, and from action to repose. The period for awaking returns as necessarily as that for sleep, and both arrive independent of any foreign cause; since in either state the animal cannot exist but for a certain time, and an uninterrupted continuity of either would be equally fatal, to life. In the animal economy, therefore, we may distinguish two parts; the one acts perpetually without interruption, and the other acts only by intervals. The action of the heart and lungs in animals that breathe, and of the heart in the f[oe]tus, seem to constitute the former as does the action of the senses, and the movements of the members of the latter. If we imagine beings endowed by nature with only the first part of this animal economy, though deprived of sense and progressive motion, would yet be animated, and differ in nothing from animals asleep. An oyster which appears to have no external sense or progressive motion, is a being formed to sleep for ever. In this sense a vegetable is merely a sleeping animal, and in general every organized being destitute of sense and motion may be compared to an animal doomed by Nature to a perpetual sleep. In animals, then, sleep is not an accidental state, occasioned by the exertions of their functions while awake. It is, on the contrary, an essential mode of existence, which serves as a basis to an animal economy. By sleep our existence begins; the f[oe]tus sleeps continually, and the infant is more often asleep than awake. Sleep, therefore, which seems to be a state purely passive, resembling that of death, is, on the contrary, that which a living animal first experiences, and is the very foundation of life. Confined solely to that part which acts continually, the most perfect animal will not appear to differ from those beings to which we can scarcely give the appellation of animal. As to external functions, it would be nearly upon a level with a vegetable; for however different the internal organization of animals and vegetables may be, the inferences will be the same. They each receive nourishment, grow, expand, have external motions, and a vegetating life. But of progressive motion, action, and sentiment, they will be equally destitute; nor be endowed with any interior or apparent character by which animal life may be distinguished. Investing, however, this internal part with senses and members, animal life will presently manifest itself; and the more this cover shall contain of sense and members, the more will the animal life be perfect. It is by this investment that animals differ from each other. The internal part belongs, without exception, to all animals; and is nearly the same in all which have flesh and blood. The external cover, however, is widely different; and it is at its extremities that the greatest differences subsist. In order to elucidate this argument, let us compare the body of a man with that of a horse or an ox. In each the heart and lungs, or the organs of circulation, and of respiration, are nearly the same; but the external cover is highly different. The materials of the animal body, though the parts are similar to those of the human, vary greatly as to number, size, and position; and thereby the dissimilitudes in their respective forms are rendered very wide. Besides, we shall find that the greatest differences are at the extremities; for in dividing the body into three principal parts, the trunk, the head, and the members, we find, that in the head and members, which are the extremities of the body, consist, the most material difference between man and other animals. We discover that the greatest difference in the trunk is at the two extremities; since in men there are clavicles at the upper extremity, which in animals are wanting; and the under extremity of animals is terminated by a tail, consisting of a certain number of exterior vertebrÆ, which the human body is without. The inferior extremity of the head also, as the jawbones, and the upper extremity, as the bones the forehead, differ prodigiously in man and beast. Finally, by comparing the members of a man with those of other animals, we plainly perceive it is at the extremities they differ most, as no two things bear less resemblance to each other, than the human hand with the foot of a horse or an ox. Taking the heart then for the centre of the animal machine, we find in that and other adjacent parts, there is a perfect resemblance between man and other animals: but the more we remove from this centre, the more they become different; and when in the centre itself there is found any difference, then the animal is infinitely more distant from man, and possesses nothing in common with those animals we are now considering. In most insects, for example, there is a peculiar organization of this principal part of the animal economy. Instead of heart and lungs, they have parts which, being subservient to the vital functions, have been considered as analogous to those viscera, but which in reality widely differ from them, both in structure and result of action, and therefore are insects to the last degree different from man and other animals. A minute difference in the centrical parts is always accompanied with an infinitely greater in the exterior parts. The tortoise, whose heart is of a peculiar structure, is a very extraordinary animal, and has not the smallest resemblance to any other animated being. In considering men, quadrupeds, birds, cetaceous animals, fishes, reptiles, &c. what prodigious variety do we find in the figure and proportion of their bodies, in the number and position of their members, in the substance of their flesh and bones? Quadrupeds have generally tails and horns; cetaceous animals live in another element, and though their mode of generation is similar to that of quadrupeds, yet they differ greatly from them in form, having no inferior extremities; birds differ still more by their beaks, feathers, wings, and their propagation by eggs; fishes and amphibious animals are yet farther removed from the human form, and reptiles have no members. In the whole exterior covering there is the greatest diversity, the interior conformation being nearly the same; they have all a heart, a liver, a stomach, intestines, and organs for generation; these ought to be considered as parts the most essential to the animal economy, since they are the most fixed, and least subjected to variation. But it is to be observed that, even in the cover, there are some parts more fixed than others. Of all the senses none of these animals are divested. We have already explained what may be their sensation of feeling. What may be the nature of their smelling and taste we know not, but we are assured they all enjoy the sense of seeing, and perhaps that of hearing also. The senses may be considered, then, as another essential part of the animal economy, as well as the brain, from which sensation derives its origin. Even insects, which differ so much in the centre of the animal economy, have a part analogous to the brain, and its functions resemble those of other animals; and such as the oyster, which seems to be deprived of a brain, ought to be considered as only half-animated, and as filling up an intermediate space between the animal and the vegetable kingdoms. As the heart is the centre of the interior part of the animal, so is the brain the centre of the cover. In like manner as the heart, and all the interior parts, communicate with the brain and exterior cover, by means of the blood-vessels, the brain communicates with the heart, and with all the interior parts, by means of the nerves. This union appears to be intimate and reciprocal, and though of these two organs the functions are absolutely different, yet they can never be separated without the instant death of the animal. The heart and the whole interior part acts continually without interruption, and independent of any exterior cause; but the senses and exterior part act only by alternate intervals, when affected by external causes. Objects act upon the senses, the senses modify this action, and carry the impression modified into the brain, where it becomes what we term sensation. In consequence of this impression the brain acts on the nerves, and communicates the vibration it has received; and this vibration it is which produces progression, and all the other exterior actions of the body. Whenever a cause acts upon a body, we know that the body also acts upon the cause. Thus objects act upon animals by means of the senses, and animals act upon the object by its exterior movements. In general action is the cause, and re-action the effect. It may be said, that in solid bodies, which follow the laws of mechanism, the re-action is always equal to the action; but that in the animal body it appears that the re-action is greater than the action, and that the other exterior movements ought not to be considered as simple effects of the impression of objects upon the senses. To this objection I reply, that though in certain cases effects appear proportioned to their causes, there is in Nature an infinite number of cases where the effects bear no kind of proportion to their apparent causes. By a single spark of fire a magazine of powder may be set in flame, and a citadel be blown up. By electricity a slight friction produces a violent shock, which is communicated to great distances, and if a thousand persons touch each other, they would all be almost as much affected by it as if the shock had been confined to each of them individually. It is not, then, extraordinary that a slight impression on the senses should produce in the animal body a violent re-action, and should manifest itself by exterior movements. The causes we are qualified to ascertain, and the quantity of whose effects we can precisely estimate, are less numerous than those whose mode of action is unknown, and of whose proportional relation with their effects, we are entirely ignorant. Now most effects in Nature depend on a number of causes differently combined, whose actions vary, and seem to be determined by no established law, consequently we can only form a conjectural estimate by endeavouring to approximate the truth by the means of probabilities. I pretend not, then, to assert as a demonstrative fact, that progressive and other exterior movements of animals, are caused solely by the impression of objects upon the senses. I mention it merely as likely, and founded on principles of analogy, since all organized beings, which are destitute of sense, are likewise destitute of progressive motion, and that all those which possess the one have also the other. To illustrate these observations let us briefly analyze the physical principles of our actions. When an object strikes any of our senses, and the sensation it produces is agreeable, it creates a desire, which desire must have a relation to some of our qualities or modes of enjoyment. The object we cannot desire but either to see, taste, hear, smell, or to touch. We desire it merely that we may render the first sensation still more agreeable, or to excite another which is a new manner of enjoying the object; for if in the moment that we perceive an object we could enjoy it fully, through all the senses at once, we should have nothing to desire. The source of desire, then, is our being badly situated with respect to the object perceived, our being either too far from, or too near to it. This being the case we naturally change our situation, because at the same time that we perceive the object, we likewise perceive the cause which prevents our obtaining a full enjoyment of it. From the impression which the object produces upon our senses, then, the motion we make in consequence of that desire, and the desire itself, solely proceeds. An object we perceive by the eye, and which we desire to touch, if within our reach, we stretch forth our hands, and if at a distance we put ourselves in motion to approach it. A man deeply immersed in thought, if he is hungry, and there is a piece of bread before him, he will seize it, and even carry it to his mouth and eat it, without being conscious that he has done so. These movements are a necessary consequence of the first impressions of objects, and would never fail to succeed this impression if other intervening impressions did not often oppose this natural effect, either by weakening or by destroying the action of the first. An organized being void of sensation, as an oyster, whose sense of feeling is probably very imperfect, is deprived not only of progressive motion, but even of sentiment and intelligence, as either of these would produce desire, which would manifest itself by exterior movement. That such beings are divested of a sense of their own existence I will not assert, but at least that sense must be very imperfect, since they have no perception of the existence of others. It is the action of objects upon the senses which creates desire, and desire progressive motion. In order to render this truth still more sensible, let us suppose a man, at the instant his will incites him to approach an object, suddenly deprived of all his members, his body reduced to a physical point, to a globular atom, and, provided the desire still subsists, he will exert his whole strength in order to change his situation. The exterior and progressive movement depends not, then, upon the organization and figure of the body and members, since whatever be the conformation any of being it will not fail to move, provided it has senses, and a desire to gratify them. On this exterior organization, indeed, depends the facility, quickness, direction, and continuity of motion, but the cause, principle, action, and determination, originate solely from desire occasioned by the impression of objects upon the senses; and if a man was deprived of them he would no longer have desire, and consequently remain constantly at rest, notwithstanding he might possess the faculties for motion. The natural wants, as that of taking nourishment, are interior movements, which necessarily create desire or appetite. By these movements exterior motions may be produced in animals, and, provided they are not deprived of exterior senses relative to these wants, they will act to satisfy them. Want is not desire; it differs from it as the cause differs from the effect. Every time the animal perceives an object, relative to its wants, desire begins, and action follows. The action of external objects must produce some effect; and this effect we readily conceive to be animal motion, as every time its senses are struck in the same manner, the same movements always follow. But how shall we comprehend the action of objects creating desire or aversion? How shall we obtain knowledge of that which operates beyond the senses, those being the intermediate between the action of objects, and the action of the animal; a power in which consists the principle of the determination of motion, since it modifies the action of the animal, and renders it sometimes null, notwithstanding the impression of objects? This question, as it relates to man, is difficult to be resolved, being by nature so different from other animals. The soul has a share in all our movements, and to distinguish the effects of this spiritual substance, from those produced by the powers of our material being alone, is an object of very great difficulty, and of which we can form no judgment but by analogy, and by comparing our actions with the natural operations of other animals. But as man alone is possessed of this spiritual substance, which enables him to think and reflect, and as the brute is a being altogether material, which neither thinks nor reflects, nevertheless acts, and seems to determine, we cannot doubt but that the principle of the determination of motion is in the animals an effect altogether mechanical, and absolutely dependant upon its organization. I conceive, therefore, that in the animal the action on objects on the senses produces another on the brain, which I consider as an interior and a general sense, which receives every impression that the exterior senses transmit to it. This internal sense is not only capable of being agitated by the action of the senses, but also of retaining for a length of time the agitations thus produced; and in the continuity of the agitation consists the impression, which is more or less deep in proportion as the agitation is more or less durable. In the first place, then, the interior sense differs from the exterior senses, in the property which it has of receiving all impressions, while the exterior senses receive them merely as they relate to their conformation; the eye, for example, being no more affected by sound than the ear is by light. Secondly, the interior differs from the exterior senses, by the duration of the agitations produced by exterior causes; but in every other respect they are of the same nature. The interior sense of the brute, as its exterior, is entirely material, and the effect of mechanical organization. We have, like the animal, this material sense; and we possess, moreover, a sense of a nature highly superior, which resides in the spiritual substance, and which animates and guides us. The brain of the animal is, therefore, a general sense, which receives all impressions the external senses transmit to it, and these impressions continue much longer in the internal than in the external senses: for instance, the agitations which light produces in the eye, continues longer than that which sound produces on the ear. It is on this account that the impressions, which the former transmits to the interior sense, are more strong than those transmitted by the latter; and that we represent to ourselves the things which we have seen much more forcibly than those which we have heard. It is even found, that of all the senses, the eye is that in which the agitations are the most durable, and in which, of consequence, though seemingly they are more explicit, the strongest impressions are formed. The eye may therefore be considered as a continuation of the interior sense. It is, indeed, nothing more than one large nerve expanded, and a prolongation of the organ, in which the interior sense resides. That in its nature there should be a greater affinity to this internal sense is not then surprising; and in effect not only its impressions are more durable, but its properties more eminent than those of the other senses. The eye represents outwardly the inward impressions. Like the internal sense, it is active, and expresses desire or aversion, while all the other senses are wholly passive; they are merely organs formed for the reception of exterior impressions, but incapable of retaining or reflecting them. When with violence, however, and for a length of time any sense is acted upon, the agitation subsists much longer than the action of the exterior objects. This is, however, felt most powerfully in the eye, which will retain the dazzling impression made by looking for a moment on the sun, for hours and even days. The brain also eminently enjoys this property, and not only retains the impressions it receives but propagates their actions, by communicating the vibrations to the nerves. The organs of the exterior senses, the brain, the spinal marrow, and the nerves, which are diffused over every part of the body, ought to be considered as one continued substance, as an organic machine, in which the senses are the parts acted upon by the external objects. But what renders this machine so different from all others is its fulcrum not only being capable of resistance and re-action, but is itself active, because it long retains impressions it has received; and the brain and its membranes being of great capacity and sensibility, it may receive a number of successive agitations, and retain them in the order in which they were received, because each impression agitates one part of the brain only, and the successive impressions agitate the same or contiguous parts, in a different manner. Should we suppose an animal which had no brain, but possessing an exterior of great sensibility and extension; an eye, for example, of which the retina was as extensive as that of the brain, and had the property of retaining, for a long space, the impressions it might receive: it is certain, that the animal so endowed would see at the same time not only the present objects, but also those it had seen before; and seeing thus the past and the present with one glance, it would be determined mechanically to act according to the number or force of the agitations produced by the images which accorded with, or were contrary to this determination. If the number of images calculated to create an appetite surpassed those that would produce disgust or loathing, the animal would necessarily be determined to move, in order to satisfy that appetite: but if their number and force were equal, having no particular cause for motion, it would remain perfectly at rest; and if the number or the force of the images of the former are equal to the number or the force of the images of the latter, the animal will remain undetermined, and in an equilibrium between these two equal powers, nor will he make any movement either to obtain or to avoid. This I say it would do mechanically, and without the intervention of memory; for as the animal sees at the same time all the images, they consequently act, and those which have an affinity to appetite and desire, counteract those which have an affinity to antipathy and disgust; and it is by the preponderance of either, that determines it to act in this or in that manner. It is evident, therefore, that in brutes the interior sense differs in nothing from the exterior but in the property of retaining the impressions it has received, a property by which alone all the actions of animals may be explained, and some idea obtained of what passes within them; a property which likewise demonstrates the essential and infinite difference which subsists between them and us, and from which may be distinguished in what respects they are similar. The degrees of excellence in the senses do not follow the same order in the brute as in the human species. The sense which has the strongest affinity to thought, is the touch. This is enjoyed by man in greater perfection than by animals. That which has the strongest affinity to instinct and appetite, is that of smelling; a sense in which man must acknowledge an infinite inferiority. Man, then, has the greatest tendency to knowledge, and the brute to appetite. In the former, the sense first in point of excellence, is the touch, and smelling the last; and this difference corresponds with the nature of each. The sense of seeing is at best uncertain, without the aid of the touch, and therefore less capable of perfection in the brute than in man. The ear, though perhaps as perfect in the former as in the latter, is of much less use to the animal, from the want of speech, which in man is an appendage to the sense of hearing, an organ of communication which renders it an active sense; whereas in the other hearing is a sense almost entirely passive. Man, then, enjoys the senses of feeling, seeing, and hearing, more perfect, and the sense of smelling more imperfectly than other animals; and as the taste is an inferior smell, and has also a stronger relation to appetite than any of the other senses, there is a sufficient probability to suppose that animals enjoy it in a more exquisite degree than man. Of this a proof might be adduced from the repugnance which animals have to certain kinds of food, and from their natural appetite for such as are proper for them; while man, unless informed of the difference, would eat the fruit of one tree for that of another, and even hemlock for parsley. The excellence of the senses proceeds from Nature; but art and habit may render them still more perfect. A painter sees, at the first glance, numbers of shades and differences, which another person will pass over unnoticed. A musician, always habituated to harmony, receives a lively sensation of pain from discord. In like manner are the senses, and even appetites of animals rendered more perfect. Birds may be taught to repeat words, and imitate tunes; and the ardour of a dog for the chace may be increased by accustoming him to a certain reward. In proportion as these senses are acute and perfect does the animal shew itself active and intelligent. In man the improvement is not so conspicuous, because he exercises his ear and his eye by means more rational and ingenious. Those persons who see, hear, or smell, imperfectly, are of no less intellectual capacity than others; an evident proof that in man there is something more than an internal animal sense. This is the soul of man, which is a superior sense, a spiritual substance, entirely different in its essence and action from the nature of the external senses. From this, however, we are not to deny that there is in man an internal material sense corresponding with the external senses. But what I maintain is, that the latter is infinitely subordinate to the other; that the spiritual substance governs it, and either destroys or creates its operations. In the animal this sense is the determinating principle of motion, but in man only the means, or the secondary cause. Let us endeavour to clear up this important point, and let us see what power this internal material sense possesses, and what it is capable of producing. The internal material sense receives promiscuously all the impressions the external senses transmit to it. These impressions proceed from the action of objects; they only pass over the external senses, and produce in them but an instantaneous vibration; they rest, however, upon the internal sense, and produce in the brain, which is its organ, durable and distinct agitations. These vibrations create appetite or disgust, inclination or repugnance, according to the present state and disposition of an animal. An animal, the instant after its birth, begins to breathe, and to feel the want of nourishment; the smell, which is the sense of appetite, receives the emanations of the milk which is contained in the teats of its mother. The vibrations which this sense undergoes, from the odoriferous particles, are communicated to the brain, which acting, in its turn, upon the nerves, the animal is stimulated to open its mouth, to obtain that sustenance of which it feels the want. The sense of appetite being less acute in man than in brutes, the infant at its birth feels only the desire of receiving nourishment, which it announces by its cries, but it cannot obtain it of itself; it receives no information from the smell, and is obliged to have its mouth put to the nipple, when the agitations, excited by the touch and smell, are communicated to the brain and nerves, and the child makes the necessary motions for sucking in its nourishment. Solely by the smell and taste, the senses of appetite, can the animal be informed of the presence of its food, and of the place where it is, as its eyes are still closed, and would, even if they were open, in no degree contribute towards the determination of motion. Vision has a greater relation to knowledge than to appetite, and in man the eye is open from the moment of his birth; in most animals it is shut for several days, but in whom the senses of appetite are far more expanded, and more perfect. The same remark is alike applicable to progressive motion, and to all the other exterior movements. A new-born infant can hardly move its members, and it is a long time before it attains strength sufficient to change its place, but in a very little time does a young animal acquire these faculties. In the animal these powers relate solely to the appetite, which is vehement, quickly developed, and the sole principle of motion; in man the appetite is weak, more slowly developed, and can have less influence than knowledge upon the determination of motion; man is necessarily, in this respect, more backward than the animal. Every thing concurs then to prove, even in a physical sense, that brutes are actuated by appetite alone, and that man is governed by a superior principle. If doubts still exist, it is from our imperfect conception how appetite alone is capable of producing, in animals, effects so much resembling those which knowledge produces among ourselves; and from the difficulty we have to distinguish what we do in virtue of knowledge, from what we do by the mere force of appetite. Yet, in my opinion, it is not impossible to dispel this uncertainty. The internal material sense retains for a long time the agitations it receives; it is a sense of which the brain is the organ, and by which all the impressions are received that each of the exterior senses transmits to it. When, therefore, an exterior impression proceeds from the senses of appetite, the animal will advance to attain, or draw back to avoid, the object of this impression. This motion, however, is liable to uncertainty when produced by the eye or the ear; because, when an animal sees, or hears, for the first time, he will be agitated by light or by sound; yet this agitation will be uncertain, since neither have any relation to appetite. It is only by repeated acts of seeing and hearing, added to the senses of taste and feeling, that it will actually advance or recede from objects which become relative to its appetite. A dog, for instance, who has been tutored, however violent his appetite, will not seize what might satisfy that appetite, although he will use every gesture to obtain it from the hand of its master. Does not this animal seem to reason between desire and fear, nearly as a man would do, who was inclined to seize upon the property of another, but was withheld by the dread of punishment? Though this analogy may be just; yet to render it in effect well-founded, should not animals be capable of performing the same actions that we perform? Now the contrary is evident; as nothing do animals either invent or perfect; in every thing they have an uniformity, and consequently no reflection. Of this analogy then we may doubt its reality, and may with propriety enquire, whether it is not by a principle different from ours that brutes are directed? and whether, without being under the necessity of allowing them the aid of reflection, the senses they enjoy are not sufficient to produce the actions they perform? Whatever relates to their appetites strongly agitates their interior sense; and on the object of this appetite the dog would instantly rush, did not this very sense retain the impressions of pain which had formerly accompanied this action. By exterior impressions the animal has been modified. This prey is not presented to a dog simply, but to one which has been chastised every time it obeyed this impulse of appetite; the agitations of pain, therefore, are renewed when those of appetite are felt, having been constantly felt at the same time. The animal being thus impelled at once by two contrary powers, two powers destructive of each other, remains between them in an equilibrium; and, as the determinate cause of its motion is counterbalanced, it makes no effort to attain the object of its appetite. Though the agitations of appetite and repugnance, or of pleasure and pain, destroy the effect of each other, in the brain a third vibration takes place, which accompanies the other two, and this is occasioned by the action of its master, from whose hand the animal has often received its food; and as this is in no degree opposed or counterbalanced, it becomes the determinative cause of motion; and the dog is therefore determined to move towards its master, and to remain in motion till its appetite is entirely satisfied. In the same manner, and upon the same principles, may we explain, however complicated they appear, all the actions of animals, without allowing them either thought or reflection; the internal sense being sufficient to produce all their movements. The nature of their sensations alone remains to be elucidated, which, from what we have asserted, must be widely different from ours. “Have animals, it may be said, no knowledge, no consciousness of their existence? Do you deprive them of sentiment? In pretending to explain their actions upon mechanical principles, do you not in fact render them mere machines, or insensible automatons?” If I have been rightly understood, it must have appeared that, far from divesting animals of all powers, I allow them every thing, thought and reflection excepted. Feelings they have, in a degree superior to ourselves. A consciousness they also have of their present, though not of their past existence. They have sensations, but they have not the faculty of comparing them, or of producing ideas: ideas being nothing more than associations of sensations. Each of these objects let us examine in particular. That animals have feelings, and in a degree even more exquisite than ourselves, I think we have already evinced, by what we have said of the excellence of their senses relative to appetite. Like ourselves then, animals are affected by pleasure and pain; they do not know good and evil, but they feel it; what is agreeable to them is good, what is disagreeable is bad, and both are nothing more than relations, suitable, or contrary to their nature and organization. The pleasure of tickling, and the pain from a hurt, as they depend absolutely on an action more or less strong upon the nerves, which are the organs of sentiment, are alike common to man and other animals. Whatever acts softly upon these organs, is a cause of pleasure, and whatever shakes them violently, is a cause of pain. All sensations, then, are sources of pleasure, while they are moderate, and natural; but so soon as they become too strong, they produce pain, which, in a physical sense, is the extreme, rather than the opposite of pleasure. A light too bright, a fire too hot, a noise too loud, a smell too strong, coarse victuals and severe friction, excite in us disagreeable sensations; whereas a delicate colour, a moderate heat, a soft sound, a gentle perfume, a fine savour, and light touch, please and move us with delight. Every gentle application to the senses, then, is a pleasure, and every violent shock a pain; and as the causes which occasion violent, happen more rarely in Nature than those which produce mild and moderate effects; and as animals, by the exercise of their senses, acquire in a little time the habit of avoiding every thing offensive or hurtful to them, and of distinguishing, and of approaching such as are pleasing; so without doubt they enjoy more agreeable sensations than disagreeable ones, and the amount of their pleasures exceed the amount of their pain. In man, physical pleasure and pain form the smallest part of his sufferings or enjoyments. His imagination, never idle, seems perpetually employed to increase his misery; presenting to the mind nothing but vain phantoms, or exaggerated images. More agitated by these illusions, than by real objects, the mind loses its faculty of judging, and even its dominion; the will, of which it has no longer the command, becomes a burthen; its extravagant desires are sorrows; and, at best, its prospects are delusive pleasures, which vanish as soon as the mind, resuming its place, is enabled to form a judgment of them. In searching for pleasure, we create ourselves pain; and seeking to be more happy, we increase our misery; the less we desire, the more we possess. In fine, whatever we wish beyond what Nature has given is pain; and nothing is pleasure but what she offers of herself. Nature presents to us pleasures without number; she has provided for our wants, and fortified us against pain. In the physical world, there is infinitely more good than evil; and therefore it is not the realities but the chimeras which we have to dread: it is not pain of body, disease, nor death that are terrible; but the agitation of the soul, the conflict of the passions, the mental anxiety, are those only we need apprehend. Animals have but one mode of enjoying pleasure; the satisfying their appetite by the exercise of their sensations. We likewise enjoy this faculty, and have another mode of acquiring pleasure, the exercise of the mind, whose appetite is knowledge. This source of pleasure would be the more pure and copious did not our passions oppose its current, and divert the mind from contemplation. So soon as these obtain the ascendancy, reason is silenced; a disgust to truth ensues; the charm of illusion increases; error fortifies, itself, and drags us on to misery; for what misery can be greater than no longer seeing things as they are; to have judgment perverted by passions; to act solely by its direction, to appear in consequence unjust or ridiculous to others; and when the hour of self-examination comes, of being forced to despise ourselves? In this state of illusion and darkness we would change the nature of our soul. She was given us for the purposes of knowledge, and we would employ her solely for those of sensation. Could we extinguish her light, far from regretting the loss, with pleasure should we embrace the lot of idiots. As we no longer reason but during intervals, and as these intervals are troublesome, and spent in secret reproaches, we wish to suppress them, and thus proceeding from one illusion to another, we at length endeavour to lose all knowledge and remembrance of ourselves. A passion without intervals is madness; and a state of madness is the death of the soul. Violent passions with intervals are fits of folly, a malady of the mind, whose danger consists in its duration and frequency. In those intervals alone it may be said to enjoy health by the resumption of wisdom, but prevents it being a state of happiness, by reflecting on and condemning the past follies. The generality of those who call themselves unhappy, are men of violent passions, or rather madmen, who have some intervals of reason; and as in exalted stations there are more false desires, more vain pursuits, more unruly passions, more abuses of the mind, than in the inferior, the rich man, beyond a doubt, is the most unhappy. But let us turn from these gloomy objects, these humiliating truths, and take a view of the man of wisdom, who alone is worthy our notice. Contented with his situation, he who is entitled to this character wishes not to live but as he has always lived: happy within himself, he stands in little need of other resources; continually occupied in exercising the faculties of his mind, he perfects his understanding, cultivates his talents, acquires new knowledge, and without remorse and disgust, he enjoys the whole universe by enjoying himself. A man like this is undoubtedly the happiest being in Nature. To the pleasures of the body, which he possesses in common with other animals, he adds those of the mind, which he enjoys exclusively. He has two methods of being happy, which aid and fortify each other: and if by indisposition or accident he is subject to pain, his sufferings are not great: his strength of mind supports him, reason consoles him, and he feels a satisfaction that he is enabled to suffer. The health of man is more precarious than that of any other animal; he is indisposed more frequently, and for a greater length of time, and dies at all ages; while brutes travel through life with an even and steady pace. This difference seems to proceed from two causes, which, though widely distinct, contribute to the same effect. The first is, the unruliness of our internal material sense; the passions have an influence on the health, and disorder the principles which animate us. Almost all mankind lead a life of timidity or contention, and the greatest part die of chagrin. The second is the imperfection of those of our senses which have an affinity with the appetite. Brute animals have a better perception of what is suitable to their nature; they are not liable to deception in the choice of their food; they are not guilty of excess in their pleasures; and guided solely by a sense of their present wants, they satisfy these without seeking new modes of gratification. As for man, independent of his propensity to excess, independent of that ardour with which he endeavours to destroy himself, by endeavouring to force Nature; he hardly knows how to distinguish the effect of this or that nourishment; he disdains simple food, and prefers artificial dishes, because his taste is depraved, and because, from being a sense of pleasure, he has rendered it an organ of debauchery, which is never gratified but when it is irritated. It is not surprising, therefore, that we are more subjected than animals to infirmities; since we know not so well as them, what may contribute to preserve or destroy health, our experience being less certain than their perception; nay we abuse the very senses of the appetite, which they enjoy in such superior excellence, these being to them the means of preserving health, and to us causes of disease and of destruction. By intemperance alone more men sicken and die, than by all the scourges incident to human nature. From these reflections it would appear, that animals have a more certain, as well as a more exquisite sensation of feeling than men. In support of this superior strength of sentiment, we may advert to their sense of smelling, which some animals enjoy to such a degree that they can smell further than they can see. A sense like this is an eye which sees objects, not only where they are, but even where they have been; it is the sense by which the brute animal distinguishes what is suitable or repugnant to its nature, and by which it perceives and chooses what is proper for the gratification of its appetite. In greater perfection, then, than man, do animals enjoy the senses which relate to appetite: and though of their present existence they have a consciousness, of their past they have none. This second proposition, as well as the first, is worthy consideration. The consciousness of existence is composed in man of the sensation of his present, and of the remembrance of his past existence. Remembrance is a sensation altogether as present as the first impression, and sometimes affects us more strongly. As these two kinds of sensations are different, and as the mind possesses the faculty of comparing and forming ideas from them, our consciousness of existence is the more certain and extensive, as remembrance more frequently and copiously recalls past things and occurrences; and as by our reflections we compare and combine them with those past and present occurrences. Every man retains within himself a certain number of sensations correspondent with the different existences or states through which he has passed; and these sensations, by the comparison which the mind forms between them, at length become a succession, and a series of ideas. In this comparison of sensations consists the idea of time; and indeed all other ideas. But this series of ideas, this chain of existences, is often presented to us in an order very different from that in which our sensations reached us; and in this it is that the difference principally consists in the genius and disposition of mankind. Some men have minds particularly active in comparing and forming ideas. These are invariably the most ingenious, and, circumstances concurring, will always distinguish themselves. There are others, and in a greater number, whose minds are less active, allow all sensations which have not a certain degree of force to escape, and who only compare those by which they are strongly agitated. In points of ingenuity and vivacity these yield to the former. Others still there are, and they form the multitude, in whom there is so little activity of mind, so little propensity to think, that they compare and combine nothing, at least at the first glance; sensations of force, and repeated a thousand times, are required before their minds will be influenced to compare them, and form ideas. The consciousness of our existence being composed, then, not only of our actual sensations, but of the train of ideas which gave rise to the comparison of our sensations, and of our past existences, it is evident that the more ideas we have, the more certain we are of our existence; that the more we have of intellectual capacity, the more we exist; that it is by the power of reflection alone that we are certain of our past existence, and view our future one; the idea of futurity being nothing more than a comparison of the present with the past inverted, since in this light the present is past, and the future present. This power of reflection being denied to animals, it is certain they cannot form ideas, and consequently their consciousness of existence is less sure, and less extensive than ours. Having no idea of time, no knowledge of the past, nor conception of the future, their consciousness of existence is simple, depends solely on the sensations which actually affect them, and consists in the internal sentiment which these sensations produce. May we not conceive what this consciousness of existence is in animals, by reflecting on our own state when strongly occupied with some object, or violently agitated by some passion, which banishes every reflection upon self? This state we familiarly express by saying, the man is absent or beside himself; and people are in reality beside themselves, when they are occupied with sensations actually present to them, especially if those sensations are so violent and rapid as to allow the mind no time for reflection. When thus situated we feel pleasure and pain in all their varieties; therefore, though seemingly without the participation of the mind, we have a consciousness of our existence. This state, to which we are occasionally exposed, is the habitual state of animals; deprived of ideas, and furnished with sensations, they know not their existence but feel it. To render more sensible this difference, let us consider minutely the faculties of brutes, and compare them with the actions of man. Like us they have senses, and receive impressions from exterior objects; they have also an interior sense, an organ which retains the agitations occasioned by those impressions, and consequently sensations which, like ours, are renewable, and are more or less strong and durable. But they have neither ingenuity, understanding, nor memory; because they are denied the power of comparing their sensations, and because these three faculties of the mind depend on this power. Have animals no memory? It will be replied, the contrary seems demonstrably evident. After a considerable absence do they not recognize the persons with whom they had lived, the places where they resided, and the roads which they had frequented? Do they not recollect the punishments, the caresses, the lessons they had received? Though deprived of imagination and understanding, every thing seems still to evince they have a memory active, extensive, and perhaps more faithful than our own. However persuasive these appearances may be deemed, and however strong may be the prejudices created by them, I presume I can demonstrate, that they deceive us, and that brute animals have no knowledge of past events, no idea of time, and of consequence no memory. In man memory flows from the power of reflection, for the remembrance of things past supposes not only the duration of the impressions on our internal material sense, or renovation of former sensations, but also the comparison which the mind has made of those sensations, or the ideas it has formed. If memory consisted merely in the renovation of past sensations, those sensations would be represented to our internal sense without leaving any determined impressions; they would present themselves without order or connection, as they do in a state of intoxication, or in dreams, when they are so incongruous, and so incoherent, that we immediately lose all recollection of them. Of such things only as have a relation to others, which preceded or followed them, do we retain a remembrance; and every solitary sensation, however powerful, passes away without leaving the smallest trace on the mind. Now it is the mind which establishes these relations of objects, by the comparison it makes between them, and connects our sensations by a continued thread of ideas. As memory consists, then, in a succession of ideas, so it necessarily supposes the power by which ideas are produced. But, if possible, to leave no doubt on this important point, let us enquire into the nature of that remembrance left by our sensations when they are accompanied with ideas. Pain and pleasure are pure sensations, and the strongest of any, yet we but feebly recollect them, and with confusion. All we remember is, that we were pleased or hurt; but this remembrance is not distinct; we cannot represent to ourselves either the kind, the degree, or the duration of those sensations by which we had been so violently agitated; and the less are we capable of representing those we had but seldom felt. A pain, for example, which we have experienced but once, which only lasted a few minutes, and differed from all former pains, would be soon forgotten; we might recollect we felt great pain, yet, though we distinctly recollected the circumstances which accompanied it, and the period at which it happened, we should have but an imperfect remembrance of the pain itself. Why is almost every thing forgotten that passed during our infancy? Why have old men a more distinct remembrance of what happened in their prime of life than what occurred in their more advanced years? Can there be a stronger proof that sensations alone are not sufficient to produce memory, and that it exists solely in the train of ideas which our minds derive from those sensations? In infancy the sensations are as lively and rapid as in manhood, yet they leave few or no traces, because at this era the power of reflection, which alone can form ideas is almost totally inactive; and because in the moments it does act, its comparisons are only superficial. In manhood reason is completely developed, because the power of reflection is in full exercise; we then derive from our sensations every possible advantage, and form many orders of ideas, and chains of thought, whereof each, from being often revolved, forms so durable and indelible an impression, that when old age comes on, those very ideas present themselves with more force than those derived from present sensations, because at that period the sensations are feeble, slow and dull, and the mind itself partakes of the languor of the body. In infancy, the time present is every thing; in manhood, we equally enjoy the past, the present and the future; in old age we have little sense of the present, we turn our eyes to the future, and exist in the past. In the infant that prattles, and the old man that dotes, reason is alike imperfect, because they are alike void of ideas; the former is as yet unable to form them, and the latter has ceased. An idiot, whose corporeal senses and organs appear to be sound, has, like us, sensations of all kinds; he will also have them in the same order, if he lives in society, and is obliged to act as other men. As these sensations do not create in him ideas, as there is no correspondence between his mind and his body, and as he is incapable of reflection, so he is necessarily destitute of memory, and all knowledge of himself. In nothing does such a man differ from a brute, as to the exterior faculties, for though he has a soul, and possesses the principle of reason, yet as this principle remains in a state of inaction, and receives nothing from the corporeal organs, it can have no influence upon his actions which are like those of an animal, solely determined by its sensations, and by a sentiment of its existence and present wants. Thus the idiot and the brute are beings whose operations are in every respect the same, because the one has no soul, and the other makes not any use of it; they are both destitute of the power of reflection, and of course have neither understanding nor memory. Should it still be said, "Do not the idiot and the brute often act as if they were determined by the knowledge of things past? Do they not distinguish persons with whom they have lived; places where they have resided; and perform many other actions, which necessarily imply memory? And does not all this prove that memory proceeds not from the power of reflection?" It must already have been perceived, that I distinguish two kinds of memory, infinitely different in their causes, though somewhat similar in their effects. The one consists in the impressions of our ideas; and the other, which I would rather term reminiscence than memory, is nothing more than the renovation of our sensations, or of the vibrations by which they were occasioned. The former issues from the mind, and is much more perfect in man than the latter; which is produced merely by the renovation of the vibrations of the internal sense, and is the only memory possessed by brutes or idiots. Their preceding sensations are renewed by their present ones; the present, and principal, calls forth the former, and the accessory images; they feel as they have felt, and therefore they act as they have acted; they behold together the present and the past, but without distinguishing or comparing, and consequently without knowing them. As another proof of the existence of memory in animals, I may be told of their dreams. It is certain that brutes, while asleep, have the things represented to them with which they have been occupied while awake. Dogs bark when they are asleep; and though this barking is feeble, yet it is easy to distinguish in it the cry of the chace, accents of rage, sounds of desire, of murmur, &c. It is not to be doubted, then, but that dogs have a lively and active memory, different too from that of which we have now been speaking, since it acts independent of any exterior cause. To clear up this difficulty, it is necessary to examine the nature of dreams, and to inquire whether they proceed from the mind, or depend entirely on our internal material sense. If we could prove that they reside solely in the latter, it would be an answer to the objection, and another demonstration, that in brutes there is neither understanding nor memory. Idiots, whose minds are without action, dream like other men; therefore dreams are produced independent of the mind. Let any person reflect upon his dreams, and endeavour to discover why the circumstances are so unconnected, and the events so extravagant. To me it appears, that it is principally because they turn solely upon sensations, and not upon ideas. With the idea of time, for example, they have no affinity. Persons are represented whom we never saw, and even those who have been dead for many years, as alive, and as they formerly were when living; but we indifferently connect them with things and persons of the present, or of a different period. Thus it is also with the idea of place; we must perceive objects where they are not, or we should not see them at all. Did the mind act in a single instant it would give order to this incongruous train of sensations. Instead of which it allows the representations to succeed each other in disorder; and though each object appears in lively colours, the succession is often confused, and always chimerical. If the mind is rather roused by the enormity or force of these sensations, it will in the midst of this darkness produce a spark of light, and create in the midst of chimeras a real idea. We then dream, or rather we will think so, for though this action is but a small sign of the soul, it is yet neither a sensation nor a dream; it is a thought, a reflection, but being too weak to dispel the illusion, it mixes with and forms a part of the dream, and prevents not the representations from succeeding; insomuch, that on awaking, we imagine we had dreamed the very things we had thought. In dreams we see much, though we but seldom understand; we are powerfully agitated by our sensations, images follow each other, without the least intervention of the mind, either to compare or reconcile them. We have sensations, then, but no ideas, the latter being comparisons of the former; so dreams must reside solely in the internal material sense; and as the mind does not produce them, they must form a part of that animal reminiscence, of which we have already treated. Memory, on the contrary, cannot exist without the idea of time, without a comparison of ideas, and as these extend not to dreams, it seems to be obvious that they can neither be a consequence nor an effect, nor a proof of memory. But though it should be maintained that to some dreams ideas certainly belong; and as a proof of it, those people be quoted who walk, speak, and converse connectedly while asleep; still it would be sufficient for my argument, that dreams may be produced by the renovation of sensations alone, for in consequence thereof the dreams of animals must be merely of this species, and such dreams, far from supposing memory, indicate nothing but a material reminiscence. By no means am I inclined to believe, that persons who walk and converse while asleep are in reality occupied with ideas. In all such actions the mind seems to have no concern. Sleep-walkers go about, return and act, without reflection or knowledge of their situation or danger; alone are their animal faculties exercised, and even of these some remain unemployed; and while in this state, a sleep-walker is of course more stupid than an idiot. As to persons who speak while asleep, they never say any thing new. An answer to certain common questions, a repetition of a few familiar expressions, may be produced, independent of the principle of thought or action of the mind. Why should we not speak without thought when asleep, since when most awake, and under the influence of passion, man utters numberless things without reflection. As to the occasional cause of dreams, by which former sensations are renewed without being excited by present objects, it is to be observed, that we never dream when our sleep is sound: every thing is then in a state of inaction, and we sleep both outwardly and inwardly. The internal sense, however, falls asleep the last, and awakes the first, because it is more active, and more easily agitated, than the external senses. It is when our sleep is less sound that we experience illusive dreams, and former sensations, those especially which require not reflection, are renewed. The internal sense being unoccupied by actual sensations from the inaction of the external senses, exercises itself upon its past sensations. Of these the most strong appear the most often; and the more they are strong, the more the situations are extravagant; and for this reason it is, that almost all dreams either terrify or charm us. That the internal material sense may act of itself, it is not necessary that the exterior senses should be absolutely in a state of repose: it is sufficient if they are without exercise. Accustomed regularly to resign ourselves to repose, we do not easily fall asleep: the body and the members, softly extended, are without motion; the eyes veiled by darkness, the tranquillity of the place, and the silence of the night, render the ear useless; alike inactive are the other senses; all is at rest, though nothing is yet lulled to sleep. In this condition, when the mind is also unoccupied with ideas, the internal material sense is the only power that acts. Then is the time for chimerical images and fluttering shadows. We are awake, and yet we experience the effects of sleep. If we are in full health, the images are agreeable, the illusions are charming; but if the body is disordered or oppressed, then we see grim and hideous phantoms, which succeed each other in a manner not more whimsical than rapid. It is a magic lanthorn, a scene of chimeras, which fill the brain, when destitute of other sensations. We remember our dreams, from the same cause that we remember sensations lately experienced; and the only difference which subsists between us and brutes is, that we can distinguish what belongs to dreams, from what belongs to our real ideas or sensations; and this is a comparison, an operation of the memory, to which the idea of time extends. While brutes, who are deprived of memory, and of this power of comparison, cannot distinguish their dreams, from their real sensations. |