SECTION VII.
MUSCULAR SENSATIONS, OR THOSE FEELINGS WHICH ACCOMPANY THE ACTION OF THE MUSCLES.
There is no part of our Consciousness, which deserves greater attention than this; though, till lately, it has been miserably overlooked. Hartley, Darwin, and Brown, are the only philosophical inquirers into Mind, at least in our own country, who seem to have been aware that it fell within the province of their speculations.
The muscles are bundles of fibres, which, by their contraction and relaxation, produce all the motions of the body. The nerves, with which they are supplied, seem to be the immediate instruments of the muscular action.
That these muscles have the power of acute sensation, we know, by what happens, when they are diseased, when they suffer any external injury, or even when, the integuments being removed, they can be touched, though ever so gently.
It has been said,6* that if we had but one sensation, and that uninterrupted, it would be as if we had no sensation at all; and, to the justice of this observation, some very striking facts appear to bear evidence. We know that the air is continually pressing upon our bodies. But, the sensation being continual, without any call to attend to it, we lose, from habit, the power of doing so. The sensation is as if it did not exist. We feel the air when it is in motion, or when it is hotter or colder, to a certain degree, than our bodies; but it is because we have the habit of attending to it in those states. As the muscles are always in contact with the same things, the sensations of the muscles must be almost constantly the same. This is one reason why they are very little attended to, and, amid the crowd of other feelings, are, in general, wholly forgotten. They are of that class of feelings which occur as antecedents to other more interesting feelings. To these the attention is immediately called off, and those which preceded and introduced them are forgotten. In such cases the thought of the less interesting sensations is merged in that of the more interesting.
6* Itaque et sensioni adhæret, proprie dictæ, ut ei aliqua insita sit perpetuo phantasmatum varietas, ita ut aliud ab alio discerni posset. Si supponeremus, enim, esse hominem, oculis quidem claris cæterisque videndi organis recte se habentibus compositum, nullo autem alio sensu præditum, eumque ad eandem rem eodem semper colore et specie sine ulla vel minima varietate apparentem obversum esse, mihi certe, quicquid dicant alii, non magis videre videretur, quam ego videor mihi per tactûs organa sentire lacertorum meorum ossa. Ea tamen perpetuo et undequaque sensibilissima membrana continguntur.—Adeo sentire semper idem, et non sentire, ad idem recidunt. Hobbes, Elem. Philos. Pars IV. c. xxv. § 5.—(Author’s Note.)
If we had not direct proof, analogy would lead us to conclude, that no change could take place, in parts of so much sensibility as the muscles, without a change of feeling; in particular, that a distinguishable feeling must attend every contraction, and relaxation. We have proof that there is such a feeling, because intimation is conveyed to the mind that the relaxation or contraction is made. I will, to move my arm; and though I observe the motion by none of my senses, I know that the motion is made. The feeling that attends the motion has existed. Yet so complete is my habit of attending only to the motion, and not to the feeling, that no attention can make me distinctly sensible that I have it. Nay, there are some muscles of the body in constant and vehement action, as the heart, of the feelings attendant upon the action of which we seem to have no cognisance at all. That this is no argument against the existence of those feelings, will be made apparent, by the subsequent explanation of other phenomena, in which the existence of certain feelings, and an acquired incapacity of attending to them, are out of dispute.15
15 The paradox, of feelings which we have no cognisance of—feelings which are not felt—will be discussed at large in a future note.—Ed.
In most cases of the muscular feelings, there is not only that obscurity, of which we have immediately spoken, but great complexity; as several muscles almost always act together; in many of the common actions of the body, a great number.
The result of these complex feelings is often sufficiently perceptible, though the feelings, separately, can hardly be made objects of attention. The unpleasant feeling of fatigue, in part at least a muscular feeling, is one of those results. The pleasure which almost all the more perfect animals, especially the young, appear to feel, in even violent exercise, may be regarded as another. The restlessness of a healthy child; the uneasiness in confinement, the delight in the activity of freedom, which so strongly distinguish the vigorous schoolboy; seem to indicate, both a painful state of the muscular system in rest, and a pleasurable state of it in action. Who has not remarked the playful activity of the kitten and the puppy? The delight of the dog, on being permitted to take exercise with his master, extends through the greater part of his life.
One of the cases in which the feeling of muscular action seems the most capable of being attended to, is the pleasure accompanying the act of stretching, which most animals perform in drowsiness, or after sleep.
A very slight degree of reflection is sufficient to evince, that we could not have had the idea of resistance, which forms so great a part of what we call our idea of matter, without the feelings which attend muscular action. Resistance means a force opposed to a force; the force of the object, opposed to the force which we apply to it. The force which we apply is the action of our muscles, which is only known to us by the feelings which accompany it. Our idea of resistance, then, is the idea of our own feelings in applying muscular force. It is true, that the mere feeling of the muscles in action is not the only feeling concerned in the case. The muscles move in consequence of the Will; and what the Will is, we are not as yet prepared to explain. What is necessary at present is, not to shew all the simple feelings which enter into the feeling of resistance; but to shew that the simple feeling of muscular action is one of them.
The feeling of resistance admits of great varieties. The feeling of a plate of iron is one thing, the feeling of a blown bladder is another, the feeling of quicksilver is a third, the feeling of water a fourth, and so on. The feeling of weight, or attraction, is also a feeling of resistance.
SECTION VIII.
SENSATIONS IN THE ALIMENTARY CANAL.
When the sensations in the alimentary canal become acutely painful, they are precise objects of attention to every body.
There is reason to believe that a perpetual train of sensations is going on in every part of it. The food stimulates the stomach. It undergoes important changes, and, mixed with some very stimulating ingredients, passes into the lower intestines; in every part of which it is still farther changed. The degree, and even the nature, of some of the changes, are different, according as the passage through the canal is slower, or quicker; they are different, according to the state of the organs, and according to the nature of the food.
Of the multitude of sensations, which must attend this process, very few become objects of attention; and, in time, an incapacity is generated, of making them objects of attention. They are not, however, as we shall afterwards perceive, feeble agents, or insignificant elements, in the trains of thought. They are of that class of feelings, to which we have already been under the necessity of alluding; a class, which serve as antecedents, to feelings more interesting than themselves; and from which the attention is so instantaneously drawn, to the more interesting feelings by which they are succeeded, that we are as little sensible of their existence, as we often are of the sound of the clock, which may strike in the room beside us, and of course affect our ear in the usual manner, and yet leave no trace of the sensations behind.
The complicated sensations in the intestinal canal, like those in the muscles, though obscure, and even unknown, as individual sensations, often constitute a general state of feeling, which is sometimes exhilarating, and sometimes depressing. The effects of opium, and of inebriating liquors, in producing exhilaration, are well known; and though much of the pleasure in these states is owing to association, as we shall afterwards explain, yet the agreeable feelings in the stomach, are the origin and cause of the joyous associations.16 The state of feeling in the stomach in seasickness, or under the operation of an emetic, is, on the contrary, one of the most distressing within our experience; though we can neither call it a pain, nor have any more distinct conception of it, than as a state of general uneasiness.
16 The exact mode of operation of opium and alcohol is still unknown; but the part affected is probably the nervous substance and not the stomach. It can hardly be said with propriety that any part of the pleasure of these stimulants is due to association. No doubt the exhilarated tone of the mind is favourable to the flow of joyful ideas, which serve to heighten the pleasure; but that pleasure could not be arrested or subdued through the absence of any supposable associations.—B.
The general effects of indigestion are well known. When the organs of digestion become disordered, and indigestion becomes habitual, a sense of wretchedness is the consequence; a general state of feeling composed of a multitude of minor feelings, none of which individually can be made an object of attention.
In the sense of wretchedness, which accompanies indigestion, and which sometimes proceeds to the dreadful state of melancholy madness, it is difficult to say, how much is sensation, and how much association. One thing is certain; that sensations which are the origin of so much misery are of high importance to us; whether they, or the associations they introduce, are the principal ingredient in the afflicting state which they contribute to create.
The effects of indigestion in producing painful associations, is strikingly exemplified by the horrible dreams which it produces in sleep; not only in those whose organs are diseased; but in the most healthy state of the stomach, when it has received what, in ordinary language, is said, whether from quantity or quality, to have disagreed with it.
The general states of feeling composed of the multitude of obscure and unnoticed feelings in the alimentary canal, though most apt to be noticed when they are of the painful kind, are not less frequently of the pleasurable kind. That particular sorts of foods, as well as liquors, have an exhilarating effect, needs hardly to be stated. And it is only necessary to revive the recollection of the feeling of general comfort, the elasticity, as it seems, of the whole frame, the feeling of strength, the disposition to activity and enjoyment, which every man must have experienced, when his digestion was vigorous and sound.17
17 These effects pass beyond the influence of mere digestion. All the viscera contribute to the condition of high general vigour and comfort here supposed. If one were to venture upon a scale of relative importance of the different organs, one would place the nervous centres first, and the digestion second.
The present section is open to several remarks. Some qualification must be given to the author’s surmise ‘that a perpetual train of sensations is going on in every part of the alimentary canal.’ It is hardly correct to say that there are perpetual sensations in any part of it: during a great part of our time we are in a state of indifference as to stomachic changes; and not merely because we are not disposed to attend to them, but because they scarcely exist. The sensibility of the organ is shown, on anatomical grounds, to be mainly in the stomach, and in the rectum; these parts are supplied by the nervus vagus; and very few nerves, besides those of the sympathetic system, are found in the smaller, or in the larger intestine, so that the sensitiveness of those parts is manifested only in case of violent disorganization, as cramp, stoppage, or inflammation. Hence the feelings are principally attendant on the changes in the stomach, as when food has just been taken, and after long privation, when the state called hunger shows itself.
It is not correct to class the sensations of the alimentary canal, as a whole, with those that lose their hold of the attention, that become unheeded in themselves, and are valued only as the antecedents of other more pleasurable feelings. The remark is inapplicable to the sensations mainly characterized as pleasure or pain; nothing can be more interesting than a pleasure, except a still greater pleasure. It applies only to those slight irritations that are in themselves nothing, but may be the symptoms or precursors of ill health, or of returning good health.
The author’s doctrine as to our acquiring artificially the habit of not attending to alimentary states, demands a fuller explanation. The usual cause of inattention to impressions is unbroken continuance; in accordance with the universal law of Relativity or Change, we are usually insensible to the contact of our clothing with the skin, except at the moments when we put on or take off any part of it. In walking, and in standing, for a length of time, we are insensible to the body’s weight; on rising from the recumbent position we are rendered in some degree conscious of it. Now as the alimentary sensations—Hunger and Repletion—are intermitted and alternated with other states, they fulfil the chief condition of wakeful consciousness.
The example of the striking of the clock, adduced in the text, brings into operation a different power of the mind, which may go far to counteract the influence of change. Under a very engrossing sensation, or occupation, we become insensible to the stimulation of the senses by other agents. The strain of the mind in some one direction causes a sort of incapacity for going out in any other direction while the strain lasts. This is the explanation of the indifference to the striking of the clock. By the farther influence of habit, inattention to a certain class of impressions may become habitual; as in the power of carrying on mental work in the midst of distracting noises.
The same effect may arise in connection with the alimentary feelings. A person very much engrossed with a subject is unconscious of hunger, and does not feel the pleasures of eating. Should any one be absorbed habitually with some occupation or pursuit, such an one may contract a settled indifference to the recurring phases of alimentary sensation; but this is an extreme and unusual case. Any ordinary degree of interest in the avocations and pursuits of business is compatible with full attention to the feelings of hunger, and of repletion, as well as to the occasional pains and discomforts of indigestion. We do not often choose to contract an indifference to pleasures, and we seldom succeed in acquiring an indifference to pains, although we may have moments of such indifference, under some special engrossment of mind by other things.
It is over-rating the influence of association to make it a chief element in the pleasure of intoxicating stimulants, or in the wretched feelings of diseased digestion. These states are direct results of physical agency, and are the same throughout all stages of life, with many or with few opportunities of being associated with other feelings. They are not the cases favourable for illustrating the power of association, in the important department of the feelings.—B.
CHAPTER II.
IDEAS.
“Hæc in genere sors esse solet humana, ut quid in quovis genere recte aut cogitari aut effici possit sentiant prius quam perspiciant. Laborem autem haud ita levem illum veriti, qui in eo impendendus erat ut, ideas operatione analytica penitus evolventes, quid tandem velint, aut quænam res agatur, sibi ipsis rationem sufficientem reddant, confusis, aut saltem haud satia explicatis rationibus, ratiocinia, et scientiarum adeo systemata superstruere solent communiter, eoque confidentius, quo ejus quam tractant scientiæ fundamentum solidum magis ignorant.”—Schmidt-Phiseldek, Philos. Criticæ Expositio Systematica, t. i. p. 561.
“Pour systematiser une science, c’est-à-dire, pour ramener une suite de phénomènes à leur principe, à un phénomène élémentaire qui engendre successivement tous les autres, il faut saisir leurs rapports, le rapport de génération qui les lie; et pour cela, il est clair qu’il faut commencer par examiner ces différens phénomènes séparément.”—Cousin, Fragm. Philos., p. 8.
THE sensations which we have through the medium of the senses exist only by the presence of the object, and cease upon its absence; nothing being here meant by the presence of the object, but that position of it with respect to the organ, which is the antecedent of the sensation; or by its absence, but any other position.
It is a known part of our constitution, that when our sensations cease, by the absence of their objects, something remains. After I have seen the sun, and by shutting my eyes see him no longer, I can still think of him. I have still a feeling, the consequence of the sensation, which, though I can distinguish it from the sensation, and treat it as not the sensation, but something different from the sensation, is yet more like the sensation, than anything else can be; so like, that I call it a copy, an image, of the sensation; sometimes, a representation, or trace, of the sensation.
Another name, by which we denote this trace, this copy, of the sensation, which remains after the sensation ceases, is IDEA. This is a very convenient name, and it is that by which the copies of the sensation thus described will be commonly denominated in the present work. The word IDEA, in this sense, will express no theory whatsoever; nothing but the bare fact, which is indisputable. We have two classes of feelings; one, that which exists when the object of sense is present; another, that which exists after the object of sense has ceased to be present. The one class of feelings I call SENSATIONS; the other class of feelings I call IDEAS.
It is an inconvenience, that the word IDEA is used with great latitude of meaning, both in ordinary, and in philosophical discourse; and it will not be always expedient that I should avoid using it in senses different from that which I have now assigned. I trust, however, I shall in no case leave it doubtful, in what sense it is to be understood.
The term Sensation has a double meaning. It signifies not only an individual sensation; as when I say, I smell this rose, or I look at my hand: but it also signifies the general faculty of sensation; that is, the complex notion of all the phenomena together, as a part of our nature.
The word Idea has only the meaning which corresponds to the first of those significations; it denotes an individual idea; and we have not a name for that complex notion which embraces, as one whole, all the different phenomena to which the term Idea relates. As we say Sensation, we might say also, Ideation; it would be a very useful word; and there is no objection to it, except the pedantic habit of decrying a new term. Sensation would in that case be the general name for one part of our constitution, Ideation for another.
It is of great importance, before the learner proceeds any farther, that he should not only have an accurate conception of this part of his constitution; but should acquire, by repetition, by complete familiarity, a ready habit of marking those immediate copies of his sensations, and of distinguishing them from every other phenomenon of his mind.
It has been represented, that the sensations of sight and hearing leave the most vivid traces; in other words, that the ideas corresponding to those sensations, are clearer than others. But what is meant by clearer and more vivid in this case, is not very apparent.
If I have a very clear idea of the colour of the trumpet which I have seen, and a very clear idea of its sound which I have heard, I have no less clear ideas of its shape, and of its size; ideas of the sensations, neither of the eye, nor of the ear.
It is not easy, in a subject like this, to determine what degree of illustration is needful. To those who are in the habit of distinguishing their mental phenomena, the subject will appear too simple to require illustration. To those who are new to this important operation, a greater number of illustrations would be useful, than I shall deem it advisable to present.
It is necessary to take notice, that, as each of our senses has its separate class of sensations, so each has its separate class of ideas. We have ideas of Sight, ideas of Touch, ideas of Hearing, ideas of Taste, and ideas of Smell.
1. By Sight, as we have sensations of red, yellow, blue, &c., and of the innumerable modifications of them, so have we ideas of those colours. We can think of those colours in the dark; that is, we have a feeling or consciousness, which is not the same with the sensation, but which we contemplate as a copy of the sensation, an image of it; something more like it, than any thing else can be; something which remains with us, after the sensation is gone, and which, in the train of thought, we can use as its representative.
2. The sensations of Touch, according to the limitation under which they should be understood, are not greatly varied. The gentle feeling, which we derive from the mere contact of an object, when we consider it apart from the feeling of resistance, and apart from the sensation of heat or cold, is not very different, as derived from different objects. The idea of this tactual feeling, therefore, is not vivid, nor susceptible of many modifications. On the other hand, our ideas of heat and cold, the feelings which we call the thought of them, existing when the sensations no longer exist, are among the most distinct of the feelings which we distinguish by the name of ideas.
3. I hear the Sound of thunder; and I can think of it after it is gone. This feeling, the representative of the mere sound, this thinking, or having the thought of the sound, this state of consciousness, is the idea. The hearing of the sound is the primary state of consciousness; the idea of the sound is the secondary state of consciousness; which exists only when the first has previously existed.
The number of sounds, of which we can have distinct ideas, as well as distinct sensations, is immense. We can distinguish all animals by their voices. When I hear the horse neigh, I know it is not the voice of the ox. Why? Because I have the idea of the voice of the ox, so distinct, that I know the sensation I have, is different from the sensation of which that is the copy or representative. We can distinguish the sounds of a great number of different musical instruments, by the same process. The men, women, and children, of our intimate acquaintance, we can distinguish, and name, by their voices; that is, we have an idea of the past sensation, which enables us to declare, that the present is the voice of the same person.
4. That the sensations of Taste recur in thought, when the sensation no longer exists, is a point of every man’s experience. This recurring, in thought, of the feeling which we have by the sense, when the feeling by the sense is gone, is the idea of that feeling, the secondary state of consciousness, as we named it above.18 That we can distinguish a very great number of tastes, and distinguish them accurately, is proof that we have a vast number of distinct ideas of taste; because, for the purpose of making such distinction, we have just seen that there must be a sensation and an idea; the sensation of the present object, and the idea of the sensation of each of the other objects from which we distinguish it. You have tasted port wine, and you have tasted claret; when you taste claret again, you can distinguish it from port wine; that is, you have the idea of the taste of port wine, in conjunction with the sensation of claret. You call it bad claret. Why? Because, along with the present taste, you have the idea of another, which, when it was sensation, was more agreeable than the present sensation.
18 Discrimination and Retentiveness (the having of Ideas as the produce of Sensations) are different functions, although mutually involved, and, in all likelihood, developed in proportionate degrees in the same organ. We begin by discriminating changes of impression; this process is necessary in order to our having even a sensation; the more delicate the discriminating power, the greater the number of our primary sensations. He that can discriminate twenty shades of yellow has twenty sensations of yellow; the two statements express the same fact. These various sensations being often repeated, acquire at last an ideal persistence; they can be maintained as ideas, without the originals. The function or power of the Intellect whereby they are thus rendered self-subsisting as ideas, is not the same function as discrimination; we call it Memory, Retentiveness, Adhesiveness, Association, and so on. What may be affirmed about it, on the evidence of induction, is, that where discrimination is good, memory or retentiveness is also good. The discriminative eye for colour is accompanied with a good memory for colour; the musical ear is both discriminative and retentive.—B.
5. Since we distinguish smells, as well as tastes, we have the same proof of the number and distinctness of the ideas of this class of sensations. There is none of the numerous smells to which we have been accustomed, which we do not immediately recognise. But for that recognition the idea of the past sensation must be conjoined with the present sensation.
6. Of that class of sensations, which I have called sensations of disorganization, we have also ideas. We are capable of having the thought of them when the sensation is gone; and that thought is the idea. A spark from the candle flew upon my hand: I had the sensation of burning. I at this moment think of that sensation; that is, I have the idea of that sensation; and I can think of it, as different from ten thousand other painful sensations: that is, I have ideas of as many other sensations of this class.
7. The ideas of the sensations which attend the action of the muscles are among the most important of the elements which constitute our being. From these we have the ideas of resistance, of compressibility, of hardness, of softness, of roughness, of smoothness, of solidity, of liquidity, of weight, of levity, of extension, of figure, of magnitude, of whole and of parts, of motion, of rest. It is, indeed, to be observed, that these are all complex ideas, and that other feelings than the mere muscular feeling are concerned in their composition. In almost all the ideas referrible to the muscular feelings, of sufficient importance to have names, the Will is included. The muscular action is the consequent, the Will the antecedent; and the name of the idea, includes both. Thus the idea of resistance is the thought, or idea, of the feelings we have, when we will to contract certain muscles, and feel the contraction impeded.19 20
19 Rather, when we will to contract certain muscles, and the contraction takes place, but is not followed by the accustomed movement of the limb; what follows, instead, being a sensation of pressure, proportioned to the degree of the contraction. It is not the muscular contraction itself which is impeded by the resisting object: that contraction takes place: but the outward effect which it was the tendency, and perhaps the purpose, of the muscular contraction to produce, fails to be produced.—Ed.
20 It is unnecessary to advert to the operation of the Will, (in the first instance at least,) in considering the feelings of muscular action. The will is the principal, but not the only, source of our activity. The mere spontaneous vigour of the system may put the muscles in motion. Likewise the muscular pleasure itself operates, by the fundamental law of the will, for its own continuance; a process not commonly called voluntary. In these circumstances, it seems advisable to consider and describe the consciousness of muscular exertion by itself, and without reference to the will.—B.
There is no feeling of our nature of more importance to us, than that of resistance. Of all our sensations, it is the most unintermitted; for, whether we sit, or lie, or stand, or walk, still the feeling of resistance is present to us. Every thing we touch, at the same time resists; and every thing we hear, see, taste, or smell, suggests the idea of something that resists. It is through the medium of resistance, that every act by which we subject to our use the objects and laws of nature, is performed. And, of the complex states of consciousness, which the philosophy of mind is called upon to explain, there is hardly one, in which the feeling or idea of resistance is not included.
It is partly owing to this combination of something else with the muscular feeling, in all the states of consciousness to which we have given names, that it is so difficult to think of the mere muscular feeling by itself; that our notion of the muscular sensations is so indistinct and obscure; and that we can rather be said to have ideas of certain general states of muscular feeling, as of fatigue, or activity, composed of a great number of individual feelings, than of the individual feelings themselves.
8. As the feelings, or sensations which we have in the intestinal canal, are almost always mixed up indistinctly with other feelings, and, except in the cases of acute pain, are seldom taken notice of but as constituting general states, we hardly have the power of thinking of those sensations one by one; and, in consequence, can hardly be said to have ideas of them. They are important, as forming component parts of many complex ideas, which have great influence on our happiness. But to unfold the mystery of complex ideas, other parts of our mental process have yet to be explained.
There is a certain distressful feeling, called the feeling of bad health, which is considerably different in different cases, but in which sensations of the intestinal canal are almost always a material part.
Indigestion is the name of an idea, in which the feelings of the intestinal canal are mainly concerned.
Hunger, and thirst, are also names of ideas, which chiefly refer to sensations in the same part of our system.21 22
21 Thirst is a sensation of the fauces and of the stomach; it is also a feeling of the body generally, due to a deficiency of water in the blood. It is also caused by an excess of saline ingredients in the system. In like manner, a distinction is to be drawn between Inanition, from deficiency of nutritive material in the body, and Hunger, or the state of the stomach preparatory to the act of eating. The two states must in a great measure concur: yet they may be distinct.
The account of the organic states given in this chapter would have come in appropriately under Sensation—B.
22 I venture to think that it is not a philosophically correct mode of expression, to speak of indigestion, or of hunger and thirst, as names of ideas. Hunger and thirst are names of definite sensations; and indigestion is a name of a large group of sensations, held together by very complicated laws of causation. If it be objected, that the word indigestion, and even the words hunger and thirst, comprehend in their meaning other elements than the immediate sensations; that the meaning, for instance, of hunger, includes a deficiency of food, the meaning of indigestion a derangement of the functions of the digestive organs; it still remains true that these additional portions of meaning are physical phenomena, and are not our thoughts or ideas of physical phenomena; and must, therefore, in the general partition of human consciousness between sensations and ideas, take their place with the former, and not with the latter.—Ed.
It is proper to remark, that, beside the internal feelings to which I have hitherto directed the reader’s attention, there are others, which might be classed, and considered apart. The blood-vessels, for example, and motion of the blood, constitute an important part of our System, not without feelings of its own; feelings sometimes amounting to states which seriously command our attention. Of the feelings which accompany fever, a portion may reasonably be assigned to the change of action in the blood-vessels.
There are states of feeling, very distinguishable, accompanying diseased states of the heart, and of the nervous and arterial systems.
Beside the blood and its vessels, the glandular system is an important part of the active organs of the body; not without sensibility, and of course, not without habitual sensations. The same may be said of the system of the absorbents, of the lymphatics, and of the vascular system in general.
The state of the nerves and brain, the most wonderful part of our system, is susceptible of changes, and these changes are accompanied with known changes of feeling. There is a class of diseases which go by the name of nervous diseases: and though they are not a very definite class; though it is not even very well ascertained how far any morbid state of the nerves has to do with them; it is not doubtful that in some of those diseases there are peculiar feelings, which ought to be referred to the nerves. The nerves and brain may thus be, not only the organs of sensations, derived from other senses, but organs of sensations, derived from themselves. On this subject we cannot speak otherwise than obscurely, because we have not distinct names for the things which are to be expressed.
It is not, however, necessary, in tracing the simple feelings which enter into the more complex states of consciousness, to dwell upon the obscurer classes of our inward sensations; because it is only in a very general way that we can make use of them, in expounding the more mysterious phenomena. Having never acquired the habit of attending to them, and having, by the habit of inattention, lost the power of remarking them, except in their general results, we can do little more than satisfy ourselves of the cases in which they enter for more or less of the effect.
We have now considered what it is to have sensations, in the simple, uncompounded cases; and what it is to have the secondary feelings, which are the consequences of those sensations, and which we consider as their copies, images, or representatives. If the illustrations I have employed have enabled my reader to familiarize himself with this part of his constitution, he has made great progress towards the solution of all that appears intricate in the phenomena of the human mind. He has acquainted himself with the two primary states of consciousness; the varieties of which are very numerous; and the possible combinations of which are capable of composing a train of states of consciousness, the diversities of which transcend the limits of computation.23 24
23 The Sensation and the Idea compared.—Great importance, in every way, attaches to the points of agreement and of difference of the Sensation and of the Idea. By the Sensation, we mean the whole state of consciousness, under an actual or present impression of sense, as in looking at the moon, in listening to music, in tasting wine. By the Idea is meant the state of mind that remains after the sensible agent is withdrawn, or that may be afterwards recovered by the force of recollection.
1. For many purposes the sensation and the idea are identical. They are compared to original and copy, which, although not in all respects of equal value, can often answer the same ends. A perfect recollection of a process that we wish to repeat, is as good as actually seeing it. For all purposes of knowledge, and of practical guidance, a faithful remembrance is equal to the real presence. So, as regards the emotional ideas, or the recollection of states of pleasure and of pain, which prompt our voluntary actions, in pursuit and in avoidance, the memory operates in the same way as the original fact, allowance being made for difference of degree. A pleasing melody induces us to listen to it, and to crave for its repetition; the after recollection of it, also moves us to hear it again. If we find ourselves in the midst of distracting noises, we are impelled to escape; the mere remembrance, at an after time, has the same influence on the will.
2. It is highly probable, if not certain, that the same nervous tracks of the brain are actuated during the sensation, and during the idea, with difference of degree corresponding to the difference of vivacity or intensity of the actual and remembered states.
Of the points wherein the Sensation and the Idea are found to differ, the most obvious is their degree of intensity. We are able to maintain in idea, the state of mind corresponding to the sight of the sun, the sound of a bell, or the smell of a rose, but we are conscious of a great inferiority in the degree or vividness of the state. The bright luminosity of the original sun turns into a feeble effect, without dazzle or excitement. The thrill of a fine musical air cannot be sustained by the mere memory of it, even in the freshness of the immediately succeeding moment. A certain pleasing remembrance attaches to a good dinner, but how far below the original! Moreover, in a complicated object of sense, a great many of the parts and lineaments drop entirely out of view. Memory is unequal to retaining, without long familiarity and practice, the exact picture of a landscape, a building, or an interior. The difference in the fulness of the idea, as compared with the sensation, is no less remarkable than the difference of vivacity or intensity. This inferiority in the idea as compared with the actuality is of very various amount; being in some cases very great, and in others very slight. The difference is in proportion to the mind’s power of retentiveness, a power varying according to several circumstances or conditions, which have to be distinctly enunciated by the Psychologist. For example, it is well known, that frequency of repetition enables the idea to grow in vivacity and in fulness, and to approximate in those respects to the original. It is also known, that some minds are by nature retentive, and, by a small number of repetitions, gain the point that others reach only by a greater number.
Now, that the vivacity and fulness of a remembered idea should constitute the exact measure of the mind’s retentiveness in that particular instance, is a thing of course. There is no other measure of retentiveness but the power of reproducing in idea, what has been before us, in actuality, or as sensation; and the greater the approach of the idea to the original sensation, the better is the retaining faculty.
There is an apparent exception to this general principle. The memory of the same idea, or the same feeling, in the same person, may be at one time full and vivid, and at another time meagre and faint. In particular moments, we may recall former experiences with especial force, as if there were something that co-operated with the proper force of retentiveness. What, then, are these additional or concurring forces? Hume recognises the influence of disease in giving preternatural intensity to ideas.
The answer is that some other recollection concurs with, and adds its quota to the support of, the one in question. When, in the view of one natural prospect, we recall another with great fulness, the present sensation supplies or fills in the parts of the remembered scene; which scene, therefore, does not exist in the mind by memory alone, but as a compound of memory and actuality. So while listening with pleasure to a band of music, we remember strongly the pleasure of some previous musical performance; yet, the vivid consciousness of the past is not dependent upon the memory of the past, but upon the stimulus of the present; we are more properly under sensation, than under idea. In all mental resuscitation, there is a degree of vividness and of fulness, due to the proper retentiveness of the mind for each particular thing, according to natural power, repetition, &c. Whatever is beyond this, must be ascribed to the accidental concurrence of other stimulants, either of present sensation, or of remembered impressions.
In recollection, there is an influence designated by the term “excitement," which means that portions of the brain are in a state of exalted activity. Any ideas embodied in the parts so excited, if in operation at all, are more than ordinarily vivid. Thus in fever, faded memories brighten up into vivacity and clearness. To this case the same remark applies; the result is partly memory, or the proper retentiveness of the system, and partly an excitation of the brain, through present influences. The proper power of memory is a constant quantity, varying only with repetition, and the strict conditions of memory; the intensity or fulness of a resuscitated idea is a complex result of memory proper and present stimulants, or sensations.
Difference of vividness was the only distinction adverted to by Hume in his Psychology, which resolved all our intellectual elements into Impressions and Ideas. His opening words are:—“All the perceptions of the human mind resolve themselves into two distinct kinds, which I shall call impressions and ideas. The difference between these consists in the degrees of force and liveliness, with which they strike upon the mind, and make their way into our thought or consciousness.” He afterwards allows that in particular circumstances, as in sleep, in fever, or in madness, our ideas may approach in vividness to our sensations.
Another distinction between the Sensation and the Idea, is of the most vital importance. To the Sensation belongs Objective Reality; the Idea is purely Subjective. This distinction lies at the root of the question of an External World; but on every view of that question, objectivity is connected with the Sensation; in contrast to which the Idea is an element exclusively mental or subjective.
Meanings of Sensation.—The word Sensation has several meanings, not always clearly distinguished, and causing serious embroilments in philosophical controversy.
1. There being, in Sensation, the concurrence of a series of physical or physiological facts with a mental fact, the name may be inadvertently employed to express the physical, as well as the mental element, or at all events to include the physical part as well as the mental.
The change made on the retina by light, and the nervous influences traversing the brain, may very readily be considered as entering into the phenomenon of sensation. This, however, is an impropriety. The proper use of “Sensation” is to signify the mental fact, to the exclusion of all the physical processes essential to its production.
2. In ordinary Sensation, as in looking round a room, there is a double consciousness,—objective and subjective. In the objective consciousness, we are affected with the qualities named magnitude, distance, form, colour, &c.; these are called object properties, properties of the external and extended universe. In the subject consciousness, we are alive to states of pleasure or of pain, which may go along with the other. We do not usually exist in both modes at one instant; we pass out of one into the other. Now the word Sensation covers both, although, to the object consciousness, “Perception” is more strictly applicable; and in contrast to Perception, Sensation would mean the subjective consciousness, the moments when we relapse from the object attitude and become subjective or self-conscious, or alive to pleasure and pain. When the mind is in the object phase, it is neutral or indifferent as respects enjoyment.
3. In Sensation, a distinction may be drawn between the present effect upon the mind, or the impression that would arise if the outward agent had operated for the first time, and the total of the past impressions of the same agent, which by its repetition are recalled to fuse with the present effect. The present view of the moon reinstates the sum total of the previous views held by memory, and is not what we should experience if we saw the moon for the first time. Now, if the recall of the previous impressions, or of the joint and iterated idea, be considered an addition made by the Intellect, being dependent on the retentive power of the mind, Sensation, as opposed to Intellect, would mean the force of the present impression and nothing more; or the difference between the vividness of reality, and the inferior vividness of recollection. What we can retain when we shut our eyes would represent the force of our intelligence; the additional intensity when we resume our gaze, would represent the power of sensation or the actual experience.
This distinction suggests an important remark as to the whole nature of Sensation, namely, that there can hardly be such a thing as pure Sensation, meaning Sensation without any admixture of the Intellect. We may attribute this purity to the earliest impressions made upon the mind, but not to anything known in the experience of the adult. This mixture of Intellect with Sense is not confined to Retentiveness; the other intellectual functions, Discrimination and perception of Agreement, are inseparable from the exercise of the senses. We cannot have a sensation without a feeling of difference; warmth is a transition from cold, and a conscious discrimination of the two facts. So, whenever we repeat a sensation, we have the consciousness of the repetition, or agreement. Were not these modes of consciousness present, we should have no sensation, indeed no consciousness. There is thus no hard line between sense and intellect. The question as to the origin of our Ideas in Sense is not a real question, until we explain what we mean by Sense, and make allowance for this unavoidable participation of Intellect in sensation.
4. Sensation is commonly used to employ the whole of our primary feelings and susceptibilities, as opposed to the Emotions which are secondary or derived. It thus confounds together two different sides of our susceptibility, the active and the passive; the feelings arising in connection with our exertion of inward force or energy, and those arising under impressions from external things. Both are primary states of consciousness; they are alike dependent on modifications of our sensitive tissues. But, between the two, there is a contrast, wide, deep, and fundamental, completely missed by the older Psychologists, to the detriment of their handling of such vital questions as the origin of knowledge, and the perception of a material world. The name Sensation, pointing immediately to the operation of the five senses, gave the slip to the feelings of energy, or brought them in partially and inadequately. Yet it is the only name we have for the primary susceptibilities of the organism including both movement and passive sensibility.—B.
24 A question which, as far as I know, has been passed over by psychologists, but which ought not to be left unanswered, is this: Can we have ideas of ideas? We have sensations, and we have copies of these sensations, called ideas of them: can we also have copies of these copies, constituting a second order of ideas, two removes instead of one from sensation?
Every one will admit that we can think of a thought. We remember ourselves remembering, or imagine ourselves remembering, an object or an event, just as we remember or imagine ourselves seeing one. But in the case of a simple idea of sensation, i.e. the idea or remembrance of a single undivided sensation, there seems nothing to distinguish the idea of the idea, from the idea of the sensation itself. When I imagine myself thinking of the colour of snow, I am not aware of any difference, even in degree of intensity, between the image then present to my mind of the white colour, and the image present when I imagine myself to be seeing the colour.
The case, however, is somewhat different with those combinations of simple ideas which have never been presented to my mind otherwise than as ideas. I have an idea of Pericles; but it is derived only from the testimony of history: the real Pericles never was present to my senses. I have an idea of Hamlet, and of Falstaff; combinations which, though made up of ideas of sensation, never existed at all in the world of sense; they never were anything more than ideas in any mind. Yet, having had these combinations of ideas presented to me through the words of Shakespeare, I have formed what is properly an idea not of an outward object, but of an idea in Shakespeare’s mind; and I may communicate my idea to others, whose idea will then be an idea of an idea in my mind. My idea of Pericles, or my idea of any person now alive whom I have never seen, differs from these in the circumstance that I am persuaded that a real object corresponding to the idea does now, or did once, exist in the world of sensation: but as I did not derive my idea from the object, but from some other person’s words, my idea is not a copy of the original, but a copy (more or less imperfect) of some other person’s copy: it is an idea of an idea.
Although, however, the complex idea I have of an object which never was presented to my senses, is rightly described as an idea of an idea; my remembrance of a complex idea which I have had before, does not seem to me to differ from the remembered idea as an idea differs from a sensation. There is a distinction between my visual idea of Mont Blanc and the actual sight of the mountain, which I do not find between my remembrance of Falstaff and the original impression from which it was derived. My present thought of Falstaff seems to me not a copy but a repetition of the original idea; a repetition which may be dimmed by distance, or which may, on the contrary, be heightened by intermediate processes of thought; may have lost some of its features by lapse of time, and may have acquired others by reference to the original sources; but which resembles the first impression not as the thought of an object resembles the sight of it, but as a second or third sight of an object resembles the first. This question will meet us again in the psychological examination of Memory, the theory of which is in no small degree dependent upon it.—Ed.
CHAPTER III.
THE ASSOCIATION OF IDEAS.
“To have a clear view of the phenomena of the mind, as mere affections or states of it, existing successively, and in a certain series, which we are able, therefore, to predict, in consequence of our knowledge of the past, is, I conceive, to have made the most important acquisition which the intellectual inquirer can make.”
Brown, Lectures, i. 544.
THOUGHT succeeds thought; idea follows idea, incessantly. If our senses are awake, we are continually receiving sensations, of the eye, the ear, the touch, and so forth; but not sensations alone. After sensations, ideas are perpetually excited of sensations formerly received; after those ideas, other ideas: and during the whole of our lives, a series of those two states of consciousness, called sensations, and ideas, is constantly going on. I see a horse: that is a sensation. Immediately I think of his master: that is an idea. The idea of his master makes me think of his office; he is a minister of state: that is another idea. The idea of a minister of state makes me think of public affairs; and I am led into a train of political ideas; when I am summoned to dinner. This is a new sensation, followed by the idea of dinner, and of the company with whom I am to partake it. The sight of the company and of the food are other sensations; these suggest ideas without end; other sensations perpetually intervene, suggesting other ideas: and so the process goes on.
In contemplating this train of feelings, of which our lives consist, it first of all strikes the contemplator, as of importance to ascertain, whether they occur casually and irregularly, or according to a certain order.
With respect to the SENSATIONS, it is obvious enough that they occur, according to the order established among what we call the objects of nature, whatever those objects are; to ascertain more and more of which order is the business of physical philosophy in all its branches.
Of the order established among the objects of nature, by which we mean the objects of our senses, two remarkable cases are all which here we are called upon to notice; the SYNCHRONOUS ORDER, and the SUCCESSIVE ORDER. The synchronous order, or order of simultaneous existence, is the order in space; the successive order, or order of antecedent and consequent existence, is the order in time. Thus the various objects in my room, the chairs, the tables, the books, have the synchronous order, or order in space. The falling of the spark, and the explosion of the gunpowder, have the successive order, or order in time.
According to this order, in the objects of sense, there is a synchronous, and a successive, order of our sensations. I have SYNCHRONICALLY, or at the same instant, the sight of a great variety of objects; touch of all the objects with which my body is in contact; hearing of all the sounds which are reaching my ears; smelling of all the smells which are reaching my nostrils; taste of the apple which I am eating; the sensation of resistance both from the apple which is in my mouth, and the ground on which I stand; with the sensation of motion from the act of walking. I have SUCCESSIVELY the sight of the flash from the mortar fired at a distance, the hearing of the report, the sight of the bomb, and of its motion in the air, the sight of its fall, the sight and hearing of its explosion, and lastly, the sight of all the effects of that explosion.25
25 There is here raised the interesting and important question, how far are we able to entertain synchronous sensations; in other words, whether or not we can be cognisant of a plurality of sensations at the same instant of time. There are various circumstances tending to obscure this point; the chief being the extreme rapidity of our mental transitions.
It is requisite to view the question from two sides, the side of sensation and the side of action. On the first, the appearances are more in favour of plurality; on the second, more in favour of unity.
As regards Sensation, we are incessantly solicited by a variety of agencies, outward and inward. We may be roused into consciousness, through the eye, through the ear, through the touch, through the taste, through the smell, through the organic sensibilities; and all this at the same time with the rise of emotions or ideas through purely mental causes. Nay more; even under a single sense, we may have a plurality of distinguishable impressions. Sight is the greatest example. Hearing is little inferior; witness the complexity of a band of music, and the tumult of a stormy sea. In Touch, likewise, we may have a plurality of distinguishable feelings of contact over the body.
The point to be considered, then, is, how many of these multitudinous effects, strictly synchronous in their occurrence, are capable of operating synchronously, either in directing the thoughts, or in impressing the memory. How many of them are able to work the smallest assignable change upon the consciousness? To all appearance, more than one at a time.
Consider first the two senses most concerned in developing (out of muscular feeling as the basis) the notion of Space or Extension; that is, Touch and Sight. It will be enough to comment upon Sight. The eye, as is known, takes in a wide prospect; the retinas of the two eyes combined can embrace a large fraction of the surrounding visible sphere. Now, the attention at any one moment is confined to a limited portion: the precise limits are not here considered; there being a complication of action with sensation proper, which will be adverted to afterwards. But, notwithstanding this confinement of the attention, there is a consciousness of the whole visible expanse; as is proved in the case of any sudden change at any part; the attention is then instantly diverted to that part. We might say that there is, at every moment, a ramified area of sensibility, at its maximum in the centre—the line of direction of the eyes, and decreasing to the extremity or circumference of the visible expanse. To one gazing at the heavens, the flash of a meteor would be felt throughout the whole area of visibility; while it would be more certain in its effect, the nearer it was to the line of perfect vision, which is the place of special attention. A faint corruscation arising near the circumference might pass unheeded.
Next as to the sense of Hearing. Peculiar difficulties attend the explanation of this sense. There is only one main line of access to the inner ear, where the nerves are distributed, namely, the solid chain of bones of the middle ear; and that line can hardly be supposed capable of conveying at the same instant a plurality of different series of vibrations. Yet we fancy that we hear a concurring plurality of sounds. Of what avail would be a band of a hundred performers if there were no power of taking in simultaneous pulses of sound? There is, however, an absence of accurate investigation of this point; no one has endeavoured to ascertain how much of the complex effect is due to the rapid transitions of the ear from one sound to another, how much to the concurrence of several series of pulses in one augmented series, and how much to the composition of successive effects in the ear into a synchronous whole in the emotional wave, or general excitement of the brain. It will be found, by any careful observer, that in listening to a band, we are really occupied with very few of the sounds at the same instant of time; we perform a number of rapid movements of the attention from one to another; while, at each moment, we are under an influence remaining from the recently occurring beats, to which we are not now giving our full attention.
Touch is exactly parallel to Sight, and need not be dwelt upon. In Smell, and in Taste, we may have a plurality of distinguishable effects at one moment: we often experience complex odours and tastes. The above remarks will apply to these. The undoubted tendency of the mind is to single out, for attention, the separate constituents by turns, and to pass with rapidity from one to another; while it is also true that the individual effects that are for the moment seemingly neglected, still exercise an influence on the consciousness; which would be decisively shown (as in the case of sight) on any occasion of their suddenly increasing in force, or suddenly vanishing. Also, in their state of having fallen out of attention, they still leave an influence to modify the present sensation, the effect of their being attended to in the previous instant. Until we can measure the rapidity of those transitions of the attention, we are not in a position to affirm absolutely the power of double, triple, or multiple attention, although to all practical intents such a power is possessed.
It is certain that the mind is every moment actuated and determined by a plurality of influences, impressions, considerations, thoughts. Almost every act of the will is a resultant of many motives. Our thoughts seldom spring up at the instance of a simple link of association; although it may happen that some one link is sufficing and overpowering, and therefore governs the recall; yet there are almost always others aiding or checking the particular resuscitation. Nevertheless, such complication of antecedents is not inconsistent with the theory of very rapid transitions of attention, there being a certain persisting influence from each separate act. There would, however, be a greater theoretical simplicity, as well as a less appearance of straining a point, if we could suppose that the several conspiring agencies unite in a strictly synchronous whole.
Let us next view the question from the side of Activity. Here the circumstance that would most decisively limit the power of attention, and impose an absolute unity (qualified by rapidity of transition) is the singleness of the muscular executive. No one organ can perform two movements at the same instant. Plurality can arise only by the separate organs performing separate actions.
In such a case as playing on the pianoforte, there is a very complicated series of muscular exertions. The eyes are occupied with the printed music; both hands are exerted, and every finger performs a separate note; the foot also may be brought into action. At the same time, the ear has to be on the alert. The plurality is here very great; yet it seems much greater than it is. For, at the stage when such a performance is possible, there is a great amount of acquirement; many synchronous groupings have been made by long repetition, so as to dispense with attending to the several acts in separation. The real attention is concentrated on one, or on a very few acts; so few that it is not impossible for them to be commanded by the mere rapidity of transition from one to another. The performer need not attend to the notes of the music, and to the action of the fingers at the same absolute instant of time.
It is in the case of commencing some act entirely new to us, that the limitation of the muscular executive is most apparent. In learning the first elements of any accomplishment by imitating a master, the whole attention is concentrated on single movements; at one instant on the master, and the next instant on the act of imitating; the only synchronous addition to this last being the remaining trace of the impression of the model. If the act is complicated, and requires concurring movements of different organs, the attention, at the outset, must be given to one at a time; the conjunction of independent movements is not a primitive, but an acquired power. Previous to acquired groupings, the restriction of the attention to one movement is the rule.
Let us now consider the senses as compounded of passive sensation and movement. The eye, for example, is a moving organ under the command of the will; both eyes being moved in one indivisible volition. Visual attention consists sometimes in moving the eyes to and fro, at other times, in fixing them in one immoveable attitude. We have seen that so far as the optical sensibility is concerned, there is at each instant an effective impression of a wide area, although of very unequal distinctness. The impressions derived from the movements of the eye are much more limited. At the same absolute instant of time, we can scan only a very small portion; say the outline of some isolated form, or the trace of an isolated movement. We can run rapidly round the circumference of a round body, or along the edge of a cubical block. In looking at a tree, we perform a series of muscular sweeps, scarcely including, at one time, more than a single outline course. No doubt our optical sensibility is receiving, in a faint way, a complicated superficies; yet the ocular sweep, on which we depend for our ideas of form, can hardly be supposed to take more than one line at the same instant. The rapidity of transition is very great; but there is a conscious transition when we wish to combine the impression of a circle inscribed in a square.—B.