Kitabı oku: «Lectures on the Philosophy of the Human Mind (Vol. 1 of 3)», sayfa 21

Since the mere pains of appetite, however, most important as they truly are, for the ends which they immediately answer, are yet of little importance in relation to our general knowledge, it is unnecessary to dwell on them at length. But I cannot quit the consideration of them, without remarking that admirable provision which the gracious Author of Nature has made by them, for the preservation not of our being merely, but of our well-being– of that health and vigour, without which, a frail and feverish existence, at least in its relation to this earthly scene, would be of little value. The daily waste of the body requires daily supply to compensate it; and if this supply be neglected, or be inadequate – or, on the other hand, if it be inordinately great, disease is the necessary consequence. To preserve the medium, therefore, or at least to prevent any very great deviation from it, He, who planned our feelings and faculties as well as our bodily frame, has made it painful for us to omit what is so important to life; and painful also to prolong the supply in any great proportion, after the demands of nature have been adequately satisfied. If food had afforded gratification only as relieving the pain of hunger, these natural boundaries of appetite would have required no aid from moral or physical lessons of temperance. But the indulgence of nature, in conferring on us the sense of taste, and making food a luxury as well as a relief, we abuse, as we abuse her other kindnesses. The pleasures of this most intemperate of senses, may lead, in some degree, beyond the due point of supply, the greater number of mankind; and may drive, to excesses more injurious, all those herds of unthinking sensualists who prefer the sickly enjoyment of an hour, to the health and virtue, and intellectual as well as physical comfort, of more frugal repasts. Yet even to them, nature points out in the feeling of satiety, where intemperance begins, or where it has already begun; and if they persist, notwithstanding this feeling, how much more would they be in danger of over-loading the powers of life, if there had been no such feeling of growing uneasiness, to suppress the avidity of insatiable indulgence.

“Though a man knew,” says Dr Reid, “that his life must be supported by eating, reason could not direct him when to eat, or what; how much, or how often. In all these things, appetite is a much better guide than reason. Were reason only to direct us in this matter, its calm voice would often be drowned in the hurry of business, or the charms of amusement. But the voice of appetite rises gradually, and, at last, becomes loud enough to call off our attention from any other employment.”⁶¹

If indeed, the necessary supply were long neglected, the morbid state of the body which would ensue, though no pain of actual hunger were to be felt, would convince, at last, the sufferer of his folly. But the providence of our gracious Creator, has not trusted the existence of man to the dangerous admonition of so rough a monitor, which might, perhaps, bring his folly before him only when it was too late to be wise. The pain of hunger – that short disease, if it may be so termed, which it is in our power so speedily to cure, prevents diseases that more truly deserve the name. Between satiety on one side, and want on the other, the stream of health flows tranquilly along, which, but for these boundaries, would speedily waste itself and disappear; as the most magnificent river, which, if dispersed over a boundless plain, would flow almost into nothing, owes its abundance and majestic beauty to the very banks that seem to confine its waters within too narrow a channel.

Besides those particular feelings of bodily uneasiness, which, as attended with desire, constitute our appetites, there are other affections of the same class, which, though not usually ranked with our external sensations or perceptions, because we find it difficult to ascribe them to any local organ, are unquestionably to be arranged under the same head; since they are feelings which arise, as immediately and directly from a certain state of a part of the nervous system, as any of the feelings which we more commonly ascribe to external sense. Of this kind is that muscular pleasure of alacrity and action, which forms so great a part of the delight of the young of every species of living beings, and which is felt, though in a less degree, at every period of life, even the most advanced; or which, when it ceases in age, only gives place to another species of muscular pleasure – that which constitutes the pleasure of ease – the same species of feeling, which doubles, to ever one, the delight of exercise, by sweetening the repose to which it leads, and thus making it indirectly, as well as directly, a source of enjoyment.

In treating of what have been termed the acquired perceptions of vision, which are truly what give to vision its range of power, and without which the mere perception of colour would be of little more value than any other of the simplest of our sensations, I shall have an opportunity of pointing out to you some most important purposes, to which our muscular feelings are instrumental; and in the nicer analysis which I am inclined to make of the perceptions commonly ascribed to touch, – if my analysis be accurate – we shall find them operating at least as powerfully. At present, however, I speak of them merely as sources of animal pleasure or pain, of pleasure during moderate exercise and repose, and of pain during morbid lassitude, or the fatigue of oppression and unremitted labour.

The pleasure which attends good health, and which is certainly more than mere freedom from pain, is a pleasure of the same kind. It is a pleasure, however, which, like every other long continued bodily pleasure, we may suppose, to be diminished by habitual enjoyment; and it is therefore, chiefly, on recovery from sickness, when the habit has been long broken by feelings of an opposite kind, that we recognize what it must originally have been; if, indeed it be in our power to separate, completely, the mere animal pleasure from those mingling reflecting pleasures which arise from the consideration of past pain, and the expectation of future delight. To those among you, who know what it is to have risen from the long captivity of a bed of sickness, I need not say, that every function is, in this case, more than mere vigour; it is a happiness, but to breathe and to move; and not every limb merely, but almost every fibre of every limb, has its separate sense of enjoyment. “What a blessed thing it is to breathe the fresh air!” said Count Struensee, on quitting his dungeon, though he was quitting it only to be led to the place of execution, and cannot, therefore, be supposed to have felt much more than the mere animal delight.

 
“He does not scorn it, who, imprisoned long
In some unwholesome dungeon, and a prey
To sallow sickness, which the vapours, dank
And clammy of his dark abode have bred,
Escapes at last to liberty and light;
His cheek recovers soon its healthful hue;
His eye relumines its extinguish'd fires;
He walks, he leaps, he runs – is wing'd with joy,
And riots in the sweets of every breeze.”⁶²
 

On these mere animal gratifications, however, I need not dwell any longer. There is much more to interest our curiosity, in the sensations and perceptions which more frequently go under those names; to the consideration of which I shall proceed in my next Lecture.

LECTURE XVIII
ON THE MORE DEFINITE EXTERNAL AFFECTIONS OF MIND IN GENERAL

In my Lecture yesterday, after some further elucidation of the triple division which we formed of the mental phenomena, as external or sensitive affections of the mind, intellectual states of the mind, – emotions, – I proceeded to consider the first of these divisions, of which the characteristic distinction is, that the phenomena included in it have their causes or immediate antecedents external to the mind itself. In this division, I comprehended, together with the feelings which are universally ascribed to certain organs of sense, many feelings, which, though unquestionably originating in states of our bodily organs, as much as our other sensations, are yet commonly ranked as a different order – such as our various appetites, or rather that elementary uneasiness which is only a part, but still an essential part of our appetites, and which is easily distinguishable from the mere desire, which is the other element; since, however rapid the succession of them may be, we are yet conscious of them as successive. The particular uneasiness, it is evident, must have been felt as a sensation before the desire of that which is to relieve the uneasiness could have arisen. To the same class, too, I referred the various organic feelings, which constitute the animal pleasure of good health, when every corporeal function is exercised in just degree; and in a particular manner, our muscular feelings, whether of mere general lassitude or alacrity; or those fainter differences of feelings which arise in our various motions and attitudes, from the different muscles that are exercised, or from the greater or less contraction of the same muscles. These muscular feelings, though they may be almost unnoticed by us, during the influence of stronger sensations, are yet sufficiently powerful, when we attend to them, to render us, independently of sight and touch, in a great measure sensible of the position of our body in general, and of its various parts; and comparatively indistinct as they are, they become, – in many cases, as in the acquired perceptions of vision, for example, and equally too, as I conceive, in various other instances, in which little attention has been paid to them by philosophers, —elements of some of the nicest and most accurate judgments which we form.

It is, however, to that widest and most important order of our external affections, which comprehends the feelings more commonly termed sensations, and universally ascribed to particular organs of sense, that we have now to proceed. In these, we find the rude elements of all our knowledge, the materials on which the mind is ever operating, and without which, it seems to us almost impossible to conceive that it could ever have operated at all, or could, even in its absolute inactivity, have been conscious of its own inert existence.

This order of our external feelings comprehends all those states of mind, however various they may be, which immediately succeed the changes of state, produced, in any of our organs of sense, by the presence of certain external bodies. The mental affections are themselves, – as I have said, – commonly termed sensations; but we have no verb, in our language, which exactly denotes what is expressed in the substantive noun. To feel is, in its two senses, either much more limited or much more general, being confined, in its restricted meaning, to the sensations of one organ, that of touch, – and as a more general word, being applicable to all the varieties of our consciousness, as much as to those particular varieties, which are immediately successive to the affections of our organs of sense. We are said, in this wider use of the term, to feel indignation, love, surprise, as readily as we are said to feel the warmth of a fire, or the coldness of snow.

In defining our sensations, to be those mental affections, which are immediately successive to certain organic affections, produced by the action of external things, it is very evident, that I have made two assumptions, – first of the existence of external things, that affect our organs of sense; and, secondly of organs of sense, that are affected by external things; – unless, indeed, the assumption of the existence of organs of sense be considered, – as in philosophic truth it unquestionably is – only another form of the assumption of the existence of external things, since, in relation to the sentient mind, the organs thus supposed to exist, are, in strictness of language, external, as much as the objects supposed to act upon them. All of which we are truly conscious, in sensation, is the mental affection, the last link of the series, in the supposed process; what we term our perceptions of organs of sense, or of other external things that act upon these – our ideas, for example, of a brain or an eye, a house or a mountain, being as truly states of our own percipient mind, and nothing but states of our own mind, as our feeling of joy or sorrow, hope or fear, love or hate, – to which we never think of giving an existence, nor a direct and immediate cause of existence, out of ourselves. By the very constitution of our nature, however, or by the influence of associations as irresistible as intuition itself, – it is impossible for us not to feel this essential reality in the causes of one set of our mental affections, in the same manner as it is impossible for us to ascribe it to another set. The brain, the eye, the house, the mountain, we believe, and cannot but believe, to have external existence, independent of our own; the joy and sorrow, hope and fear, love and hate, we believe, and cannot but believe, to be merely states of our own mind, occasioned by other former states of mind, and dependent, therefore, for their continuance, on our own continued existence only. Even in our wildest dreams, – in which we imagine all things that are possible, and almost all things which are impossible; we never consider our joy or sorrow, as directly indicative of any thing separate from ourselves, and independent of us, it was still only the cliff, the wood, the pool, which we considered as external: the sorrow with which we mourned along our gloomy track, the pain with which we swam the turbid water, the horror which we felt at the antic shapes, with which we mingled in the ghostly dance, were felt to be wholly in ourselves, and constituted, while they lasted, the very feeling of our own existence. – The belief of an external world is, however, to come afterwards under our full examination: – It is sufficient, for the present, to know, that in the period after infancy, to which alone our memory extends, we are led, irresistibly, to believe in it; and that the belief of it, therefore, in whatever manner it may have originated in the imperfect perceptions of our infancy, is now, when those perceptions are mature, so completely beyond the power of argument to overcome, that it exists, as strongly, in those who reason against it, as in those who reason for it; – that the reference to a direct external cause, however, does not accompany every feeling of our mind, but is confined to a certain number of that long succession of feelings, which forms the varied consciousness of our life, – and that the feelings, with respect to which this reference is made, are the class of sensations, which, when combined with this reference, have commonly been distinguished by the name of perceptions. That we have no perfect evidence of the external existence thus ascribed by us, – independently of our own irresistible belief of it, may be allowed to the sceptic; and the reasoning of Doctor Reid on the subject, as far as he proceeds beyond the assertion of this irresistible belief, and attempts, what has been commonly regarded as a confutation of the scepticism on this point, – by representing it as proceeding on a mistake, with respect to the nature of our ideas, – is itself, as we shall afterwards find, nugatory and fallacious. But still, notwithstanding the errors of philosophers with respect to it, the belief itself is, in the circumstances in which we now exist, so truly a part of our constitution, that to contend against it in argument would be to admit its validity, since it would be to suppose the existence of some one whom we are fairly undertaking to instruct or to confute.

 
“While o'er our limbs sleep's soft dominion spread,
What tho' our soul fantastic measures trod,
O'er fairy fields; or mourn'd along the gloom
Of pathless woods; or down the craggy steep
Hurl'd headlong, swam with pain the mantled pool;
Or scaled the cliff, – or danced on hollow winds,
With antic shapes, wild natives of the brain;”
 

In what circumstance the intuitive belief, – if, as I have said, the belief be in any case intuitive, – arises; or rather, in how large a proportion of cases, in which the reference seems primary and immediate, it is, more probably, the effect of secondary associations transferred from sense to sense, will appear better after the minute analysis on which we are to enter, of the different tribes of our sensations.

In referring to the particular class of sensations, and consequently to an external cause, a certain number only of the affections of our mind, there can be no doubt, that we proceed now, in the mature state of our knowledge, with more accuracy, than we could have attained, in that early period of life, when our original feelings were more recent. We have now a clearer and more definite belief of an external world, and of objects of sensations separate from our sensations themselves; without which general belief, previously obtained, we should as little have ascribed to an external organic cause many of our feelings, which we now ascribe to one – our sensations of sound and fragrance, for example, – as we now ascribe to such an immediate external cause, our emotions of joy or sorrow. A still more important acquisition, is our knowledge of our own organic frame, by which we are enabled, in a great measure, to verify our sensations, – to produce them, as it were at pleasure, when their external objects are before us, and in this way to correct the feelings, which have risen spontaneously, by those, which we ourselves produce. Thus, when, in reverie, our conceptions become peculiarly vivid, and the objects of our thought seem almost to exist in our presence; if only we stretch out our hand, or fix our eyes on the forms that are permanently before us, the illusion vanishes. Our organ of touch or of sight, is not affected in the same manner, as if the object that charms us in our musing dream, were really present; and we class the feeling, therefore, as a conception, – not as a sensation, – which, but for the opportunity of this correction, we should unquestionably, in many instances, have done.

But though, in forming the class of our sensations, we derive many advantages from that full knowledge which the experience of many years has given, we purchase these by disadvantages which are perhaps as great, and which are greater, from the very circumstance, that it is absolutely out of our power to estimate their amount. What we consider as the immediate sensation, is not the simple mental state, as it originally followed that corporeal change, which now precedes it; but, at least in the most striking of all the tribes of our sensations, is a very different one. We have the authority of reason, a priori, as shewing no peculiar connexion of the points of the retina with one place of bodies more than with another; and we have the authority also of observation, in the celebrated case of the young man who was couched by Cheselden, and in other cases of the same peculiar species of blindness, in which the eyes, by a surgical operation, have been rendered for the first time capable of distinct vision, that if we had had no organ of sense but that of sight, and no instinctive judgment had been superadded to mere vision, we should not have had the power of distinguishing the magnitude and distant place of objects; – a mere expanse of colour being all which we should have perceived, if even colour itself could in these circumstances, have been perceived by us as expanded. Yet it is sufficient now, that rays of light, precisely the same in number, and in precisely the same direction, as those which at one period of our life, exhibited to us colour, and colour alone, should fall once more on the same small expanse of nerve, to give us instantly that boundlessness of vision, which, almost as if the fetters of our mortal frame were shaken off, lifts us from our dungeon, and makes us truly citizens, not of the earth only, but of the universe. Simple as the principle may now seem, which distinguishes our secondary or acquired perceptions of vision from those which were primary and immediate, it was long before the distinction was made; and till a period which – if we consider it in relation to those long ages of philosophic inquiry, or, rather, most unphilosophic argumentation, which had gone before – may be considered almost as in our own time, longitudinal distance was conceived to be as completely an original object of sight as the varieties of mere colour and brilliancy. There may, therefore – though we have not yet been able, and may never be able, to discover it, – be a corresponding difference in our other sensations, which now seem to us simple and immediate. In the case of sound, indeed, there is a very evident analogy to these visual acquired perceptions; since a constant reference to place mingles with our sensations of this class, in the same manner, though not so distinctly, as in our perceptions of sight. We perceive the sound, as it were near or at a distance, in one direction rather than in another; as, in the case of longitudinal distance in vision, we perceive colour at one distance rather than at another. Yet there is as little reason, from the nature of the organic changes themselves, to suppose, that different affections of our auditory nerves should originally give us different notions of distance, as that such notions should originally be produced by different affections of the retina: and, as in sight and hearing, so it is far from improbable, that, in all our senses, there may, by the reciprocal influence of these upon each other, or by the repeated lessons of individual experience in each, be a similar modification of the original simple feelings, which, in that first stage of existence that opened to us the world and its phenomena, each individual organ separately afforded. Our reasoning with respect to them, therefore, as original organs of sense, may, perhaps, be as false, as our chemical reasoning would be, were we to attempt to infer the properties of an uncombined acid, or alkali, from our observation of the very different properties of a neutral salt, into the composition of which we know that the acid or the alkali has entered.

If, indeed, it were in our power to be introduced to a society, like that of which Diderot speaks, in his Letter on the Deaf and Dumb, and to hold communication with them, all our doubts on this subject would be removed. “What a strange society,” says he, “would five persons make, each of them endowed with one only of our five different senses; and no two of the party with the same sense! There can be no doubt, that, differing, as they must differ, in all their views of nature, they would treat each other as madmen, and that each would look upon the others with all due contempt. It is, indeed, only an image of what is happening every moment in the world; we have but one sense, and we judge of every thing.”⁶³– “There is, however,” he justly remarks, “one science, though but one science, in which the whole society of the different senses might agree, – the science which has relation to the properties of number. They might each arrive, by their separate abstractions, at the sublimest speculations of arithmetic and algebra; they might fathom the depths of analysis, and propose and resolve problems of the most complicated equations, as if they were all so many Diophantuses. It is perhaps,” he adds, “what the oyster is doing in its shell.”⁶⁴

From such a society, – if, indeed, we could hold any communication with these profound algebraists, except in their common science of numbers, – we might undoubtedly learn, what are the direct immediate affections of mind, to which our senses individually give rise, and consequently, how much, while feeling has blended with feeling, they have reciprocally operated on each other. But, in our present circumstances, unaided by intercourse with such living abstractions, it is impossible for us to remove wholly this uncertainty, as to the kind and degree of influence, which experience may have had, in modifying our primary sensations. We may wish, indeed, to be able to distinguish our present feelings, from those which the same objects originally excited; but, since no memory can go back to the period, at which we did not perceive longitudinal distance, as it were, immediately by the eye, as little, we may suppose, can any memory go back to the period, when other sensations, less interesting than those of vision, were first excited. Could we trace the series of feelings, in a single mind, – as variously modified, in the progress from infancy to maturity, – we should know more of the intellectual and moral nature of man, than is probably ever to be revealed to his inquiry, – when in ages, as remote from that in which we live, and perhaps as much more enlightened, as our own age may be said to be in relation to the period of original darkness and barbarism, he is still to be searching into his own nature, with the same avidity as now, He must, indeed be a very dull observer, who has not felt, on looking at an infant, some desire to know the little processes of thought, that are going on in his curious and active mind; and who, on reflecting on the value, as an attainment in science, which the sagest philosopher would set on the consciousness of those acquisitions which infancy has already made, is not struck with that nearness, in which, in some points, extreme knowledge and extreme ignorance may almost be said to meet. What metaphysician is there, however subtile and profound in his analytical inquiries, and however successful in the analyses which he has made, who would not give all his past discovery, and all his hopes of future discovery, for the certainty of knowing with exactness what every infant feels? The full instruction, which such a view of our progressive feelings, from their very origin, in the first sensations of life, would afford, Nature, in her wisdom, however, has not communicated to us, – more than she has communicated to us the nature of that state of being, which awaits the soul after it has finished its career of mortality. Our existence seems, in our conception of it, never to have had a beginning. As far back as we can remember any event, there is always a period, that appears to us still farther back, the events of which we cannot distinguish; as, when we look toward the distant horizon, we see, less and less distinctly, in the long line which the sunshine of evening still illuminates, plains, and woods, and streams, and hills, more distant, half melting into air, beyond which our eye can find nothing, – though we are still certain, that other woods, and streams, and plains are there, and that it is only the imperfection of our sight, which seems to bound them as in another world. It is to man, when he thinks upon his own beginning, as if he felt himself in a world of enchantment, amid the shades and flowers of which he had been wandering, unconscious of the time at which he entered it, or of the objects that are awaiting him, when he shall have arrived at the close of that path, whose windings still lead him forward, – and knowing little more, than that he is himself happy, and that the unknown Being, who has raised this magnificent scene around him, must be the Friend of the mortal, whom he has deigned to admit into it.

 
“Well pleased he scans
The goodly prospect, – and, with inward smiles,
Treads the gay verdure of the painted plain, —
Beholds the azure canopy of heaven,
And living lamps, that over-arch his head,
With more than regal splendour, – bends his ear
To the full choir of water, air, and earth;
Nor heeds the pleasing error of his thought,
Nor doubts the painted green or azure arch,
Nor questions more the music's mingling sounds,
Than space, or motion, or eternal time;
So sweet he feels their influence to attract
His fixed soul, to brighten the dull glooms
Of care, and make the destined road of life
Delightful to his feet. So, fables tell,
The adventurous hero, bound on hard exploit,
Beholds with glad surprise, by secret spell
Of some kind sage, the patron of his toils,
A visionary paradise disclosed,
Amid the dubious wild; – With streams, and shades,
And airy songs, the enchanted landscape smiles,
Cheers his long labours, and renews his frame.”⁶⁵
 

The philosophic use of the term sensation does not necessarily imply, what, in its popular use, is considered almost as involved in it; and perhaps, therefore, it may not be superfluous to warn you, that it is not confined to feelings, which are pleasurable or painful, but extends to every mental affection, that is the immediate consequence of impression on our organs of sense, – of which mental states or affections, many, and, as I am inclined to think, by far the greater number, are of a kind, that cannot be termed either agreeable or disagreeable. Of the objects of sight, for example, which are of such very frequent occurrence, how few are there, at which we look, either with pleasure or with pain, – if we except that indirect pleasure, which, in particular cases, they may afford, as communicating to us information, that is valuable in itself, or as gratifying even our idlest curiosity. To take one of the most striking cases of this sort, – though we may derive, from the perusal of a work that interests us, the purest delight, it is a delight, resulting only from the conceptions, which the author, in consequence of the happy contrivance of symbolic characters, has been able to transfuse, as it were, from his own mind into ours; but, during all the time of the perusal, sensations, almost innumerable, have been excited in us, by the separate characters, with which the pages are covered, that have never mingled even the faintest direct pleasure, with the general emotion, which they, and they alone, have indirectly produced.