The Principles of Psychology, Vols. 1-2

* Physiol. Psych., i. 351, 458-60. The full inanity of the law of relativity is best to be seen in Wundt's treatment, where the great ' allgemeiner Oesetz der Beziehung,' inyoked lo account for Weber's law as well as for the phenomena of contrast and many other matters, can only be defined as a tendency to feel all things in relation to each other ! Bless its little soul I But why does it change the things so, when it thus feels them in relation?

hole in a card, and so confined to a small part of the skin. Similarly there is a chromatic minimum of size in objects. The image they cast on the retina must needs have a certain extent, or it will give no sensation of color at all. In- versely, more intensity in the outward impression may make the subjective object more extensive. This happens, as will be shown in Chapter XIX, when the illumination is increased : The whole room expands and dwindles according as we raise or lower the gas-jet. It is not easy to explain any of these results as illusions of judgment due to the inference of a wrong objective cause for the sensation which we get. No more is this easy in the case of Weber's observation that a thaler laid on the skin of the forehead feels heavier when cold than when warm ; or of Szabadfoldi's observation that small wooden disks when heated to 122° Fahrenheit often feel heavier than those which are larger but not thus warmed ; * or of Hall's observation that a heavy point moving over the skin seems to go faster than a lighter one moving at the same rate of speed, t

Bleuler and Lehmann some years ago called attention to a strange idiosyncrasy found in some persons, and consisting in the fact that impressions on the eye, skin, etc., were accompanied by distinct sensations of sound.X Colored hearing is the name sometimes given to the phenomenon, which has now been repeatedly described. Quite lately the Viennese aurist Urbantschitsch has proved that these cases are only extreme examples of a very general law, and that all our sense-organs influence each other's sensations.§ The hue of patches of color so distant as not to be recognized was immediately, in U.'s patients, perceived when a tuning-fork was sounded close to the ear. Sometimes, on the contrary, the field was darkened by the sound. The acuity of vision was increased, so that letters too far off to be read could be read when the tuning-fork was heard. Urbantschitsch, varying his experiments, found that their

X Zwangsmassige Lichtempfindung durch Schall (Leipzig, 1881). results were mutual, and that sounds which were on the limits of audibility became audible when lights of various colors were exhibited to the eye. Smell, taste, touch, sense of temperature, etc., were all found to fluctuate when lights were seen and sounds were heard. Individuals varied much in the degree and kind of effect produced, but almost every one experimented on seems to have been in some way affected. The phenomena remind one somewhat of the

* dynamogenic ' effects of sensations upon the strength of muscular contraction observed by M. Fere, and later to be described. The most familiar examples of them seem to be the increase of pain by noise or light, and the increase of nausea by all concomitant sensations. Persons suffering in any way instinctively seek stillness and darkness. Probably every one will agree that the best way of formulating all such facts is physiological : it must be that the cerebral process of the first sensation is reinforced or otherwise altered by the other current which comes in. No one, surely, will prefer a psychological explanation here. Well, it seems to me that all cases of mental reaction to a plurality of stimuli must be like these cases, and that the physiological formulation is everywhere the simplest and the best. When simultaneous red and green light make us see yellow, when three notes of the scale make us hear a chord, it is not because the sensations of red and of green and of each of the three notes enter the mind as such, and there

* combine ' or ' are combined by its relating activity ' into the yellow and the chord, it is because the larger sum of lightwaves and of air-waves arouses new cortical processes, to which the yellow and the chord directly correspond. Even when the sensible qualities of things enter into the objects of our highest thinking, it is surely the same. Their several sensations do not continue to exist there tucked away. They are replaced by the higher thought which, although a different psychic unit from them, knows the same sensible qualities which they know.

The principles laid down in Chapter VI seem then to be corroborated in this new connection. You cannot build up one thought or one sensation out of many; and only direct experiment can inform us of what we shall perceive when we gd "Albany stimuli at once. We often hear the opinion expressed that all our sensations at first appear to us as subjective or internal, and are afterwards and by a special act on our part * extradited ' or 'projected' so as to appear located in an outer world. Thus we read in Professor Ladd's valuable work that

" Sensations ... are psychical states whose place— so tsLV as they can be said to have one — is the mind. The transference of these sensations from mere mental states to physical processes located in the periphery of the body, or to qualities of things projected in space external to the body, is a mental act. It may rather be said to be a mental achie'vement [cf. Cudworth, above, as to knowledge being co7iquering], for it is an act which in its perfection results from a long and intricate process of development. . . . Two noteworthy stages, or ' epoch-making ' achievements in the process of elaborating the presentations of sense, require a special consideration. These are ' localization,^ or the transference of the composite sensations from mere states of the mind to processes or conditions recognized as taking place at more or less definitely fixed points or areas of the body; and ' eccentric projection ' (sometimes called ' eccentric perception ') or the giving to these sensations an objective existence (in the fullest sense of the word ' objective ') as qualities of objects situated within a field of space and in contact with, or more or less remotely distant from, the body." *

It seems to me that there is not a vestige of evidence for this view. It hangs together with the opinion that our sensations are originally devoid of all spatial content, f an opinion which I confess that I am wholly at a loss to understand. As I look at my bookshelf opposite I cannot frame to myself an idea, however imaginary, of any feeling which I could ever possibly have got from it except the feeling of * Physioloj^ical Psychology, 385, 387. See also such passages as that in Bain : The Senses and the Intellect, pp. 364-6.

+ ' ' Especially must we avoid all attempts, whether avowed or concealed, to account for the spatial qualities of the presentations of sense by merely describing tlvj qualities of the simple sensations and the modes of their combination. It Is position and extension in space which constitutes the 7ery peculiarity of the objects as no longer mere sensations or affections of the mind. As sensations, they are neither out of ourselves nor possessed of iie qualities indicated by the word spread-out." (Ladd, op. cit. p. 391.)

the same big extended sort of outward fact which I now perceive. So far is it from being true that our first way of feeling things is the feeling of them as subjective or mental, that the exact opposite seems rather to be the trutL Our earliest, most instinctive, least developed kind of consciousness is the objective kind ; and only as reflection becomes developed do we become aware of an inner world at all. Then indeed we enrich it more and more, even to the point of becoming idealists, with the spoils of the outer world which at first was the only world we knew. But subjective consciousness, aware of itself as subjective, does not at first exist. Even an attack of pain is surely felt at first objectively as something in space which prompts to motor reaction, and to the very end it is located, not in the mind, but in some bodily part.

" A sensation which should not awaken an impulse to move, nor any tendency to produce an outward effect, would manifestly be useless to a living creature. On the principles of evolution such a sensation could never be developed. Therefore every sensation originally refers to something external and independent of the sentient creature. Rhizopods (according to Engeimann's observations) retract their pseudopodia whenever these touch foreign bodies, even if these foreign bodies are the pseudopodia of other individuals of their own species, whilst the mutual contact of their own pseudopodia is followed by no such contraction. These low animals can therefore already feel an outer world — even in the absence of innate ideas of causality, and probably without any clear consciousness of space. In truth the conviction that something exists outside of ourselves does not come from thought. It comes from sensation; it rests on the same ground as our conviction of our own existence. ... If we consider the behavior of new-born animals, we never find them betraying that they are first of all conscious of their sensations as purely subjective excitements. We far more readily incline to explain the astonishing certainty with which they make use of their sensations (and which is an effect of adaptation and inheritance) as the result of an inborn intuition of the outer world. . . . Instead of starting from an original pure subjectivity of sensation, and seeking how this could possibly have acquired an object! v signification, we must, on the contrary, begin by the possession of objec tivity by the sensation and then show how for reflective consciousness the latter becomes interpreted as an effect of the object, how in short the original immediate objectivity becomes changed into a remote one."*

* A. Riebl: Der Philosophischer Kriticismus, Bd. n. Theil n. p. 64 Another confusion, much more common than the denial of all objective character to sensations, is the assumption that they are all originally located ^7^5^(ie the body and are projected outward by a secondary act. This secondary judgment is always false, according to M. Taine, so far as the place of the sensation itself goes. But it happens to hit a real object which is at the point towards which the sensation is projected ; so we may call its result, according to this author, a veridical hollvxiination.'^ The word Sensation, to

* On Intelligence, part ii. bk. ii. chap. ii. §g vii, viii. Compare such statements as these : "The consequence is that when a sensation has for its usual condition the presence of an object more or less distant from our bodies, and experience has once made us acquainted with this distance, we shall situate our sensation at this distance.— This, in fact, is the case with sensations of hearing and sight. The peripheral extremity of the acoustic nerve is in the deep-seated chamber of the ear. That of the optic nerve is in the most inner recess of the eye. But still, in our present state, we never situate our sensations of sound or color in these places, but without us, and often at a considerable distance from us. . . . All our sensations of color are thus projected out of our body, and clothe more or less distant objects, furniture, walls, houses, trees, the sky, and the rest. This is why, when we afterwards reflect on them, we cease to attribute them to ourselves; they are alienated and detached from us, so fai as to appear different from us. Projected from the nervous surface in which we localize the majority of the others, the tie which connected them to the others and to ourselves is undone. . . . Thus, all our sensations are wrongly situated, and the red color is no more extended on the arm chair than the sensation of tingling is situated at my fingers* ends. They are all situated in the sensory centres of the encephalon; all appear situated elsewhere, and a common law allots to each of them its apparent situation." (Vol. II. pp. 47-53.) — Similarly Schopenhauer: "I will now show the same by the sense of sight. The immediate datum is here limited to the sensation of the retina which, it is true, admits of considerable diversity, but at bottom reverts to the impression of light and dark with their shades, and that of colors.

This sensation is through and through subjective, that is, inside of the organism and under the skin." (Schopenhauer: Satz vom Grunde, p. 58.) This philosopher then enumerates seriatim what the Intellect does to make the originally subjective sensation objective: 1) it turns it bottom side up; 2) it reduces its doubleness to singleness; 3) it changes its flatness to solidity; and i) it projects it to a distance from the eye. Again: "Sensations are what we call the impressions on our senses, in so far as they come to our consciousness as states of our own body, especially of our nervous apparatus; we call them perceptions when we form out of them the representation of outer objects." (Helmholtz; Tonempfindungen, 1870, p. 101.) —Once more : " Sensation is always accomplished in the psychic centres, but it manifests itself at the excited part of the periphery. In other words,

begin with, is constantly, in psychological literature, used as if it meant one and the same thing with the physical impression either in the terminal organs or in the centres, which is its antecedent condition, and this notwithstanding that by sensation we mean a mental, not a physical, fact. But those who expressly mean by it a mental fact still leave to it a physical place, still think of it as objectively inhabiting the very neural tracts which occasion its appearance when they are excited ; and then (going a step farther) they think that it must place itself where they place it, or be subjectively sensible of that place as its habitat in the first instance, and afterwards have to be moved so as to appear elsewhere.

All this seems highly confused and unintelligible. Consciousness, as we saw in an earlier chapter (p. 214) canno^ properly be said to inhabit any place. It has dynamic relations with the brain, and cognitive relations with everything and anything. From the one point of view we may say that a sensation is in the same place with the brain (if we like), just as from the other point of view we may say that it is in the same place with whatever quality it may be cognizing. But the supposition that a sensation primitively/eeZs either itself or its object to be in the same place ivith the brain is absolutely groundless, and neither a priori probability nor facts from experience can be adduced to show that such a deliverance forms any part of the original cognitive function of our sensibility.

Where, then, do we feel the objects of our original sensations to be ? Certainly a child newly born in Boston, who gets a sensation from the candle-flame which lights the bedroom, or from his diaper-pin, does not feel either of these objects to one is conscious of the phenomenon in the nervous centres, . . . but one perceives it in the peripheric organs. This phenomenon depends on the experience of the sensations themselves, in which there is a reflection of the subjective phenomenon and a tendency on the part of perception to return as it were to the external cause which has roused the mental state because the latter is connected with the former." (Sergi: Psychologic Physiologique (Paris, 1888), p. 189.) — The clearest and best passage I know is in Liebmann: Der Objective Anblick (1869), pp. 67-73, but it is unfortu nately too long to quote.

be situated in longitude 72° W. and latitude 41° N. He does not feel them to be in the third story of the house. He does not even feel them in any distinct manner to be to the right or the left of any of the other sensations which he may be getting from other objects in the room at the same time. He does not, in short, know anything about their space-relations to anything else in the world. The flame fills its own place, the pain fills its own place ; but as yet these places are neither identified with, nor discriminated from, any other places. That comes later. For the places thus first sensibly known are elements of the child's spaceworld which remain with him all his life ; and by memory and later experience he learns a vast number of things about those places which at first he did not know. But to the end of time certain places of the world remain defined for him as the places where those sensations ivere ; and his only possible answer to the question where anything is will be to say * therey and to name some sensation or other like those first ones, which shall identify the spot. Space means but the aggregate of all our possible sensations. There is no duplicate space known aliunde^ or created by an * epochmaking achievement ' into which our sensations, originally spaceless, are dropped. They bring space and all its places to our intellect, and do not derive it thence.

By his body, then, the child later means simply that place where the pain from the pin, and a lot of other sensations like it, were or are felt. It is no more true to say that he locates that pain in his body, than to say that he locates his body in that pain. Both are true : that pain is part of what he means by the word body. Just so by the outer world the child means nothing more than that place where the candleflame and a lot of other sensations like it are felt. He no more locates the candle in the outer world than he locates the outer world in the candle. Once again, he does both ; for the candle is part of what he means by * outer world.'

This (it seems to me) will be admitted, and will (I trust) be made still more plausible in the chapter on the Perception of Space. But the later developments of this perception are so complicated that these simple principles get easily overlooked. One of the complications comes from the fact that things wove, and that the original object which we feel them to be splits into two parts, one of which remains as their whereabouts and the other goes off as their quality or nature. We then contrast where they were with where they are. If we do not move, the sensation of where they were remains unchanged ; but we ourselves presently move, so that that also changes ; and ' where they were ' becomes no longer the actual sensation which it was originally, but a sensation which we merely conceive as possible. Gradually the system of these possible sensations, takes more and more the place of the actual sensations. ' Up * and * down ' become * subjective ' notions ; east and west grow more * correct * than * right ' and * left ' etc.; and things get at last more * truly ' located by their relation to certain ideal fixed co-ordinates than by their relation either to our bodies or to those objects by which their place was originally defined. Now this revision of our original localizations is a complex affair; and contains somefa^ts which may very naturally come to he described as translocations whereby sensations get shoved farther off than they originally appeared. Few things indeed are more striking than the changeable distance which the objects of many of our sensations may be made to assume. A fly's humming may be taken for a distant steam-whistle ; or the fly itself, seen out of focus, may for a moment give us the illusion of a distant bird. The same things seem much nearer or much farther, according as we look at them through one end or another of an opera-glass. Our whole optical education indeed is largely taken up with assigning their proper distances to the objects of our retinal sensations.

An infant will grasp at the moon ; later, it is said, he projects that sensation to a distance which he knows to be beyond his reach. In the much quoted case of the * young gentleman who was born blind,' and who was * couched ' for the cataract by Mr. Chesselden, it is reported of the patient that " when he first saw, he was so far from making any judgment about distances, that he thought all objects whatever touched his eyes (as he expressed it) as what he felt did his skin." And other patients born blind, but relieved by surgical op-

eration, have been described as bringing their hand close to their eyes to feel for the objects which they at first saw, and only gradually stretching ont their hand when they found that no contact occurred. Many have concluded from these facts that our earliest visual objects must seem in immediate contact with our eyes. But tactile objects also may be affected with a like ambiguity of situation. If one of the hairs of our head be pulled, we are pretty accurately sensible of the direction of the pulling by the movements imparted to the head.^ But the feeling of the pull is localized, not in that part of the hair's length which the fingers hold, but in the scalp itself. This seems connected with the fact that our hair hardly serves at all as a tactile organ. In creatures with vibrissce^ however, and in those quadrupeds whose whiskers are tactile organs, it can hardly be doubted that the feeling is projected out of the root into the shaft of the hair itself. We ourselves have an approach to this when the beard as a whole, or the hair as a whole, is touched. We perceive the contact at some distance from the skin.

When fixed and hard appendages of the body, like the teeth and nails, are touched, we feel the contact where it objectively is, and not deeper in, where the nerve-terminations lie. If, however, the tooth is loose, we feel two contacts, spatially separated, one at its root, one at its top. From this case to that of a hard body not organically connected with the surface, but only accidentally in contact with it, the transition is immediate. With the point of a cane we can trace letters in the air or on a wall just as with the finger-tip ; and in so doing feel the size and shape of the path described by the cane's tip just as immediately as, without a cane, we should feel the path described by the tip of our finger. Similarly the draughtsman's immediate perception seems to be of the point of his pencil, the sur-

* This Is proved by Weber's device of causing the head to be firmly pressed against a support by another person, whereupon the direction of traction ceases to be perceived. geon*s of the end of his knife, the duellist's of the tip of his rapier as it plunges through his enemy's skin. When on the middle of a vibrating ladder, we feel not only our feet on the round, but the ladder's feet against the ground far below. If we shake a locked iron gate we feel the middle, on which our hands rest, move, but we equally feel the stability of the ends where the hinges and the lock are, and we seem to feel all three at once."'^ And yet the place where the contact is received is in all these cases the skin, whose sensations accordingly are sometimes interpreted as objects on the surface, and at other times as objects a long distance off.

We shall learn in the chapter on Space that our feelings of our own movement are principally due to the sensibility of our rotating joints. Sometimes by fixing the attention, say on our elbow-joint, we can feel the movement in the joint itself; but we always are simultaneously conscious of the path which during the movement our finger-tips describe through the air, and yet these same finger-tips themselves are in no way physically modified by the motion. A blow on our ulnar nerve behind the elbow is felt both there and in the fingers. Kefrigeration of the elbow produces pain in the fingers. Electric currents passed through nerve-trunks, whether of cutaneous or of more special sensibility (such as the optic nerve), give rise to sensations which are vaguely localized beyond the nerve-tracts traversed. Persons whose legs or arms have been amputated are, as is well known, apt to preserve an illusory feeling of the lost hand or foot being there. Even when they do not have this feeling constantly, it may be occasionally brought back. This sometimes is the result of exciting electrically the nervetrunks buried in the stump

" I recently faradized," says Dr. Mitchell, ** a case of disarticulated shoulder without warning my patient of the possible result. For two years he had altogether ceased to feel the limb. As the current affected the brachial plexus of nerves he suddenly cried aloud, ' Oh the hand,— the hand I ' and attempted to seize the missing member. The phantom I had conjured up swiftly disappeared, but no spirit could have more amazed the man, so real did it seem." *

Now the apparent position of the lost extremity varies. Often the foot seems on the ground, or follows the position of the artificial foot, where one is used. Sometimes where the arm is lost the elbow will seem bent, and the hand in a fixed position on the breast. Sometimes, again, the position is non-natural, and the hand will seem to bud straight out of the shoulder, or the foot to be on the same level with the knee of the remaining leg. Sometimes, again, the position is vague; and sometimes it is ambiguous, as in another patient of Dr. Weir MitchelFs who

♦'lost his leg at the age of eleven, and remembers that the foot by degrees approached, and at last reached the knee. When he began to wear an artificial leg it reassumed in time its old position, and he is never at present aware of the leg as shortened, unless for some time he talks and thinks of the stump, and of the missing leg, when . . . the direction of attention to the part causes a feeling of discomfort, and the subjective sensation of active and unpleasant movement of the toes. With these feelings returns at once the delusion of the foot as being placed at the knee."

All these facts, and others like them, can easily be described as if our sensations might be induced by circumstances to migrate from their original locality near the brain or near the surface of the body, and to appear farther off; and (under different circumstances) to return again after having migrated. But a little analysis of what happens shows us that this description is inaccurate. The objectivity ivith which each of our sensations originally comes to us, the roomy and spatial character which is a primitive part of its content, is not in the first instance relative to any other sensation. The first time we open our eyes we get an optical object which is a place, but which is not yet placed in relation to any other object, nor identified with any place otherwise known. It is a place with which so far we are only oxiquainted. When later we know that this same place is in * front ' of us, that only means that we have learned omething about it, namely, that it is congruent with that