The Principles of Psychology, Vols. 1-2

cannot, therefore, regard the observation of Prof. Mach as any proof that the latter feelings exist.* The circumstantial evidence for the feeling of innervation thus seems to break down like the introspective evidence. But not only can we rebut experiments intended to prove it, we can also adduce experiments which disprove it. A person who moves a limb voluntarily must innervate it in any case, and if he feels the innervation he ought to be able to use the feeling to define what his limb is about, even though the limb itself were anaesthetic. If, however, the limb be totally anaesthetic, it turns out that he does not know at all how much work it performs in its contraction — in other words, he has no perception of the amount of innervation which he exerts. A patient examined by Messrs. Gley and Marillier beautifully showed this. His entire arms, and his trunk down to the navel, were insensible both superficially and deeply, but his arms were not paralyzed :

' ' We take three stone bottles — two of them are empty and weigh each 250 grams; the third is full of mercury and weighs 1850 grams. We ask L ... to estimate their weight and tell us which is heaviest. He declares that he finds them all three alike. With many days of interval we made two series of six experiments each. The result was always the same. The experiment, it need hardly be said, was arranged in * I owe the interpretation in the text to my friend and former student,Mr. E. S. Drown, whom I set to observe the phenomenon before I had observed it myself. Concerning the vacillations in our interpretation of relative motion over retina and skin, see above, p. 173.

Herr Milnsterberg gives additional reasons against the feeling of innervation, of which I will quote a couple. First, our ideas of movement are 9i\\ faint ideas, resembling in this the copies of sensations in memory. Were they feelings of the outgoing discharge, they would be original states of consciousness, not copies ; and ought by analogy to be mmd like other original states. — Second, our unstriped muscles yield no feelings in contracting, nor can they be contracted at will, differing thus in ^w?o peculiarities from the voluntary muscles. What more natural than to suppose that the two peculiarities hang together, and that the reason why we cannot contract our intestines, for example, at will, is, that we have no memory-images of how their contraction feels ? Were the supposed innervation-feeling al ways the 'mental cue,' one doesn't see why we might not have it even where, as here, the contractions themselves are unfelt, and why it might not bring the contractions about. (Die Willenshandlung, pp. 87-8.)

such wise that he could be informed neither by sight nor by hearing. He even declared, holding in his hand the bottleful of mercury, that he found it to have no weight. . . . We place successively in his hand (his eyes being still bandaged) a piece of modelling wax, a stick of hard wood, a thick India-rubber tube, a newspaper folded up lengthwise and rumpled, and we make him squeeze these several objects. He feels no difference of resistance and does not even perceive that anything is in his hand."*

M. Gley in another place f quotes experiments by Dr. Bloch which prove that the sense which we have of our limbs' position owes absolutely nothing to the feeling of innervation put forth. Dr. Bloch stood opposite the angle of a screen whose sides made an angle of about 90°, and tried to place his hands symmetrically, or so that both should fall on corresponding spots of the two screen-sides, which were marked with squares for the purpose. The average error being noted, one hand was then passively carried by an assistant to a spot on its screen-side, and the other actively sought the corresponding spot on the opposite side. The accuracy of the correspondence proved to be as great as when both arms were innervated voluntarily, showing that the consciousness of innervation in the first of the two experiments added nothing to the sense of the limbs' position. Dr. Bloch then tried, pressing a certain number of pages of a book between the thumb and forefinger of one hand, to press an equal number between the same fingers of the other hand. He did this just as well when the fingers in question were drawn apart by Indiarubber bands as when they were uninterfered with, showing that the physiologically much greater innervationcurrent required in the former case had no effect upon the consciousness of the movement made, so far as its spatial character at any rate was concerned. ij"

X Herr Sternberg (Pfltlger's Archiv, xxxvn. p. 1) thinks that he proves the feeling of innervation by the fact that when we have willed to make a movement we generally think that it is made. We have already seen some of the facts on pp. 105-6, above. 8. cites from Exner the fact that if we put a piece of hard rubber between our back teeth and bite, our front teeth seem actually to approach each other, although it is physically impossible On the whole, then, it seems as probable as anything can well be, that these feelings of innervation do not exist.

for them to do so. He proposes the following experiment : Lay the palm of the hand on a table with the forefinger overlapping its edge and flexed back as far as possible, whilst the table keeps the other fingers extended ; then try to flex the terminal joint of the forefinger without looking. You do not do it, and yet you think that you do. Here again the innervation, according to the author, is felt as an executed movement. It seems to me, as I said in the previous place, that the illusion is in all these cases due to the inveterate association of ideas. Normally our will to move has always been followed by the sensation that we have moved, except when the simultaneous sensation of an external resistance was there. The result is that where we feel no external resistance, and the muscles and tendons tighten, the invariably associated idea is intense enough to be hallucinatory. In the experiment with the teeth, the resistance customarily met with when our masseters contract is a soft one. We do not close our teeth on a thing like hard rubber once in a million times ; so when we do so, we imagine the habitual result. — Persons with amputated limbs more often than not continue to feel them as if they were still there, and can, moreover, give themselves the feeling of moving them at will. The life-long sensorial associate of the idea of 'working one's toes,' e.g. (uncorrected by any opposite sensation, since no real sensation of non-movement can come from non-existing toes), follows the idea and swallows it up. The man thinks that his toes are ' working ' (of. Proceedings of American Soc. for Psych. Research, p. 249).

Herr Loeb also comes to the rescue of the feeling of innervation with observations of his own made after my text was written, but they convince me no more than the arguments of others. Loeb 's facts are these (Pfltlger's Archiv, xliv. p. 1): If we stand before a vertical surface, and if. with our hands at different heights, we simultaneously make with them what seem to us equally extensive movements, that movement always turns out really shorter which is made with the arm whose muscles (in virtue of the arm's position) are already the more contracted. The same result ensues when the arms are laterally unsymmetrical. Loeb assumes that both arms contract by virtue of a common innervation, but that although this innervation is relatively less effective upon the more contracted arm, our feeling of its equal strength overpowers the disparity of the incoming sensations of movement which the two limbs send back, and makes us think that the spaces they traverse are the same. " The sensation of the extent and direction of our voluntary movements depends accordingly upon the impulse of our will to move, and not upon the feelings set up by the motion in the active organ." Now if this is the elementary law which Loeb calls it, why does it only manifest its effect when both hands are moving simultaneously? Why not when the same hand makes successive movements ? and especially why not when both hands move symmetrically or at the same level, but on^ oj them is weighted? A weighted hand surely requires a stronger innervation than an unweighted one to move an equal distance upwards ; and yet, as Loeb confesses, we do not tend to overestimate the path which it traverses under these circumstances. The fact is that the illusion which Loeb

If the motor cells are distinct structures, they are as insentient as the motor nerve-trunks are after the posterior roots are cut. If they are not distinct structures, but are only the last sensory cells, those at the ' mouth of the funnel,' * then their consciousness is that of kinsesthetic ideas and sensations merely, and this consciousness accompanies the rise of activity in them rather than its discharge. The entire content and material of our consciousness — consciousness of movement, as of all things else — is thus of peripheral origin, and came to us in the first instance through the peripheral nerves. If it be asked what we gain by this sensationalistic conclusion, I reply that we gain at any rate simplicity and uniformity. In the chapters on Space, on Belief, on the Emotions, we found sensation to be a much richer thing than is commonly supposed ; and this chapter seems at this point to fall into line with those. Then, as for sensationalism being a degrading belief, which abolishes all inward originality and spontaneity, there is this

has studied is a complex resultant of many factors. One of them, it seems to me, is an instinctive tendency to revert to the type of the bilateral movements of childhood. In adult life we move our arras for the most part in alternation ; but in infancy the free movements of the arms are almost always similar on both sides, symmetrical when the direction of motion is horizontal, and with the hands on the same level when it is vertical. The most natural innervation, when the movements are rapidly performed, is one which takes the movement back to this form. Our estimation meanwhile of the lengths severally traversed by the two hands is mainly based, as such estimations with closed eyes usually are (see Loeb's own earlier paper, Untersuchungen uber den Fuhlraum der Hand, in Pflilger's Archiv, xli. 107), upon the apparent velocity and duration of the movement. The duration is the same for both hands, since the movements begin and end simultaneously. The velocities of the two hands are under the experimental conditions almost impossible of comparison. It is well known how imperfect a discrimination of weights we have when we 'heft' them sinultaneously, one in either hand; and G. E. Miiller has well shown (Pflilger's Archiv, xlv. 57) that the velocity of the lift is the main factor in determining our judgment of weight. It is hardly possible to conceive of more unfavorable conditions for making an accurate comparison of the length of two movements than those which govern the experiments which are under discussion. The only prominent sign is the duration, which would lead us to infer the equality of the two movements. We consequently deem them equal, though a native tendency in our motor centres keeps them from being so.

^ This is by no means an unplausible opinion. See Vol I. p. 65. to be said, that the advocates of inward spontaneity may be turning their backs on its real citadel, when they make a fight, on its behalf, for the consciousness of energy put forth in the outgoing discharge. Let there be no such consciousness ; let all our thoughts of movements be of sensational constitution ; still in the emphasizing, choosing, and espousing of one of them rather than another, in the saying to it, *be thou the reality for me,' there is ample scope for our inward initiative to be shown. Here, it seems to me, the true line between the passive materials and the activity of the spirit should be drawn. It is certainly false strategy to draw it between such ideas as are connected with the outgoing and such as are connected with the incoming neural wave.*

If the ideas by which we discriminate between one movement and another, at the instant of deciding in our mind which one we shall perform, are always of sensorial origin, then the question arises, " Of which sensorial order need they be ? " It will be remembered that we distinguished two orders of kinsesthetic impression, the remote ones, made by the movement on the eye or ear or distant skin, etc., and the resident ones, made on the moving parts themselves, muscles, joints, etc. Now do resident images, exclusively, form what I have called the mental cue, or will remote ones equally suffice ?

There can he no doubt whatever that the mental C2ie may he either an image of the resident or of the remote kind. Although, at the outset of our learning a movement, it would seem that the resident feelings must come strongly before consciousness (cf. p. 487), later this need not be the case. The rule, in fact, would seem to be that they tend to lapse * Maine de Biran, Royer Collard, Sir John Herschel, Dr. Carpenter, Dr. Martineau, all seem to posit a force-sense by which, in becoming aware of an outer resistance to our will, we are taught the existence of an outer world. I hold that every peripheral sensation gives us an outer world. An insect crawling on our skin gives us as ' outward ' an impression as a hundred pounds weighing on our back.— I have read M. A. Bertrand's criticism of my views (La Psychologic de I'Effort, 1889); but as h« seems to think that I deny the feeling of effort altogether, I c»n get b« profit from it, despite his charming way of saying things.

more and more from consciousness, and that the more practised we become in a movement, the more ' remote ' do the ideas become which form its mental cue. What we are interested in is what sticks in our consciousness ; everything else we get rid of as quickly as we can. Our resident feelings of movement ~have no substantive interest for us at all, as a rule. What interest us are the ends which the movement is to attain. Such an end is generally an outer impression on the eye or ear, or sometimes on the skin, nose, or palate. Now let the idea of the end associate itself definitely with the right motor innervation, and the thought of the innervation's resident effects will become as great an encumbrance as we formerly concluded that the feeling of the innervation itself would be. The mind does not need it ; the end alone is enough.

The idea of the end, then, tends more and more to make itself all-sufficient. Or, at any rate, if the kinaesthetic ideas are called up at all, they are so swamped in the vivid kinaesthetic feelings by which they are immediately overtaken that we have no time to be aware of their separate existence. As I write, I have no anticipation, as a thing distinct from my sensation, of either the look or the digital feel of the letters which flow from my pen. The words chime on my mental ear^ as it were, before I write them, but not on my mental eye or hand. This comes from the rapidity with which often-repeated movements follow on their mental cue. An end consented to as soon as conceived innervates directly the centre of the first movement of the chain which leads to its accomplishment, and then the whole chain rattles off gwotsi-reflexly, as was described on pp. 115-6 of Vol. I. •

The reader will certainly recognize this to be true i^ all fluent and unhesitating voluntary acts. The only specia'i fiat there is at the outset of the performance- A man says to himself, "I must change my shirt," and involuntarily he has taken off his coat, and his fingers are at work in their accustomed manner on his waistcoat-buttons, etc. ; or we say, " I must go downstairs," and ere we know it we have risen, walked, and turned the handle of the door ; — all through the idea of an end coupled with a series of guiding

sensations which successively arise. It would seem indeed that we fail of accuracy and certainty in our attainment of the end whenever we are preoccupied with much ideal consciousness of the means. We walk a beam the better the less we think of the position of our feet upon it. We pitch or catch, we shoot or chop the better the less tactile and muscular (the less resident), and the more exclusively optical (the more remote) our consciousness is. Keep your eye on the place aimed at, and your hand will fetch it ; think of your hand, and you will very likely miss your aim. Dr. Southard found that he could touch a spot with a pencilpoint more accurately with a visual than with a tactile mental cue. In the former case he looked at a small object and closed his eyes before trying to touch it. In the latter case he placed it with closed eyes, and then after removing his hand tried to touch it again. The average error with touch (when the results were most favorable) was 17.13 mm. With sight it was only 12.37 mm.^ — All these are plain results of introspection and observation. By what neural machinery they are made possible we need not, at this present stage, inquire.

In Chapter XVIII we saw how enormously individuals differ in respect to their mental imagery. In the type of imagination called tactile by the French authors, it is probable that the kinaesthetic ideas are more prominent than in my account. We must not expect too great a uniformity in individual accounts, nor wrangle overmuch as to which one * truly ' represents the process. f * Bowditch and Southard in Journal of Physiology, vol. in. No. 3. It was found in these experiments that the maximum of accuracy was reached when two seconds of time elapsed between locating the object by eye or hand and starting to touch it. When the mark was located with one hand, and the other hand had to touch it, the error was considerably greater than when the same hand both located and touched it.

f The same caution must be shown in discussing pathological cases. There are remarkable discrepancies in the effects of peripheral anaesthesia upon the voluntary power. Such cases as I quoted in the text (p. 490) are by no means the only type. In those cases the patients could move their limbs accurately when the eyes were open, and inaccurately when they were shut. In other cases, however, the anaesthetic patients cannot move their limbs at all when the ej-^es are shut. (For reports of two such cases see Bastku in ' Brain/ Bluet in Bev. Philoa.^ xxv. 478.) M. Binet explains

I trust that I have now made clear what that * idea oi a movement ' is which must precede it in order that it be voluntary. It is not the thought of the innervation which the movement requires. It is the anticipation of the movement's sensible effects, resident or remote, and sometimes very remote indeed. Such anticipations, to say the least, determine what our movements shall be. I have spoken all along as if they also might determine that they shall be. This, no doubt, has disconcerted many readers, for it certainly seems as if a special fiat, or consent to the movement were required in addition to the mere conception of it, in many cases of volition ; and this fiat I have altogether left out of my account. This leads us to the next point in the

these (hysterical) cases as requiring the 'dynamogenic ' stimulus of light (see above, p. 377). They might, however, be cases of such congenitally defective optical imagination that the ' mental cue' was normally ' tactile ;' and that when this tactile cue failed through functional inertness of the kinaesthetic centres, the only optical cue strong enough to determine the discharge had to be an actual sensation of the eye. — There is still a third class of cases in which the limbs have lost all sensibility, even for movements passively imprinted, but in which voluntary movements can be accurately executed even when the eyes are closed. MM. Binet and Fere have reported some of these interesting cases, which are found amongst the hysterical hemianfiesthetics. They can, for example, write accurately at will, although their eyes are closed and they have no feeling of the writing taking place, and many of them do not know when it begins or stops. Asked to write repeatedly the letter a, and then say how many times they have written it, some are able to assign the number and some are not. Some of them admit that they are guided by visual imagination of what is being done. Cf. Archives de Physiologic, Oct. 1887, pp. 363-5. Now it would seem at first sight that feelings of outgoing innervation must exist in these cases and be kept account of. There are no other guiding impressions, either immediate or remote, of which the patient is conscious ; and unless feelings of innervation be there, the writing would seem miraculous. But if such feelings are present in these cases, and suffice to direct accurately the succession of movements, why do they not suffice in those other anaesthetic cases in which movement becomes disorderly when the eyes are closed.

Innervation is there, or there would be no movement ; why is the feeling of the innervation gone ? The truth seems to be, as M. Binet supposes (Rev. Philos., xxm. p. 479), that these cases are not arguments for the feeling of innervation. They are pathological curiosities ; and the patients are not really anaesthetic, but are victims of that curious dissociation or splittingoff of one part of their consciousness from the rest which we are just begin to understand, thanks to Messrs. Janet, Binet, and Gurney, and in which the split-off part (in this case the kinaesthetic sensations) may nevertheless remtdu to produce its usual effects. Compare what was said above, p. 481.

psychology of the Will. It can be the more easily treated now that we have got rid of so much tedious preliminary matter. The question is this : 7s the hare idea of a movemenfs sensible effects its sufficient mental cue (p. 497), or must there he an additional mental antecedent, in the shape of a fiat , decision, consent, volitional mandate, or other synonymous phenomenon of consciousness, before the movement can follow ? I answer : Sometimes the bare idea is sufficient, but sometimes an additional conscious element, in the shape of a fiat, mandate, or express consent, has to intervene and precede the movement. The cases without a fiat constitute the more fundamental, because the more simple, variety. The others involve a special complication, which must be fully discussed at the proper time. For the present let us turn to ideo-motor action, as it has been termed, or the sequence of movement upon the mere thought of it, as the type of the process of volition.

Wherever movement follows unhesitatingly and immediately the notion of it in the mind, we have ideo-motor action. We are then aware of nothing between the conception and the execution. All sorts of neuro-muscular processes come between, of course, but we know absolutely nothing of them. We think the act, and it is done ; and that is all that introspection tells us of the matter. Dr. Carpenter, who first used, I believe, the name of ideo-motor action, placed it, if I mistake not, among the curiosities of our mental life. The truth is that it is no curiosity, but simply the normal process stripped of disguise. Whilst talking I become conscious of a pin on the floor, or of some dust on my sleeve. Without interrupting the conversation I brush away the dust or pick up the pin. I make no express resolve, but the mere perception of the object and the fleeting notion of the act seem of themselves to bring the latter about. Similarly, I sit at table after dinner and find myself from time to time taking nuts or raisins out of the dish and eating them. My dinner properly is over, and in the heat of the conversation I am hardly aware of what I

do, but the perception of the fruit and the fleeting notion that I may eat it seem fatally to bring the act about. There is certainly no express fiat here ; any more than there is in all those habitual goings and comings and rearrangements of ourselves which fill every hour of the day, and which incoming sensations instigate so immediately that it is often difficult to decide whether not to call them reflex rather than voluntary acts. We have seen in Chapter IV that the intermediary terms of an habitual series of acts leading to an end are apt to be of this gwos^-automatic sort. As Lotze says :

" We see in writing or pianoplaying a great number of very complicated movements following quickly one upon the other, the instigative representations of which remained scarcely a second in consciousness, certainly not long enough to awaken any other volition than the general one of resigning one's self without reserve to the passing over of representation into action. All the acts of our daily life happen in this wise : Our standing up, walking, talking, all this never demands a distinct impulse of the will, but is adequately brought about by the pure flux of thought."*

In all this the determining condition of the unhesitating and resistless sequence of the act seems to be the absence oj uny conflicting notion in the mind. Either there is nothing else at all in the mind, or what is there does not conflict. The hypnotic subject realizes the former condition. Ask him what he is thinking about, and ten to one he will reply 'nothing.' The consequence is that he both believes everything he is told, and performs every act that is suggested. The suggestion may be a vocal command, or it may be the performance before him of the movement required. Hypnotic subjects in certain conditions repeat whatever they

* Medicinische Psychologie, p. 393. In his admirably acute chapter on the Will this author has most explicitly maintained the position that what we call muscular exertion is an afferent and not an efferent feeling ; *' We must affirm universally that in the muscular feeling we are not sensible of the force on its way to produce an effect, but only of the sufferance already produced in our movable organs, the muscles, after the force has, in a manner unobservable by us, exerted upon them its causality " (p. 311). How often the battles of psychology have to be fought over again, each time with heavier armies and bigger trains, though not always with such able generals I

hear you say, and imitate whatever they see you do. Dr. Fer^ says that certain waking persons of neurotic type, il one repeatedly close and open one's hand before their eyes, soon begin to have corresponding feelings in their own fingers, and presently begin irresistibly to execute the movements which they see. Under these conditions of * preparation ' Dr. Fere found that his subjects could squeeze the hand-dynamometer much more strongly than when abruptly invited to do so. A few passive repetitions of a movement will enable many enfeebled patients to execute it actively with greater strength. These observations beautifully show how the mere quickening of kinaesthetic ideas is equivalent to a certain amount of tension towards discharge in the centres.*

We know what it is to get out of bed on a freezing morning in a room without a fire, and how the very vital principle within us protests against the ordeal. Probably most persons have lain on certain mornings for an hour at a time unable to brace themselves to the resolve. We think how late we shall be, how the duties of the day will suffer ; we say, " I mtist get up, this is ignominious," etc. ; but still the warm couch feels too delicious, the cold outside too cruel, and resolution faints away and postpones itself again and again just as it seemed on the verge of bursting the resistance and passing over into the decisive act. Now how do we ever get up under such circumstances ? If I may generalize from my own experience, we more often than not get up without any struggle or decision at all. We suddenly find that we hive got up. A fortunate lapse of consciousness occurs ; we forget both the warmth and the cold ; we fall into some revery connected with the day's life, in the course of which the idea flashes across us, " Hollo ! I must lie here no longer " — an idea which at that lucky instant awakens no contradictory or paralyzing suggestions, and consequently produces immediately its appropriate motor effects. It was our acute consciousness of both the warmth and the cold during the period of struggle,