The Principles of Psychology, Vols. 1-2

"The patient, when his eyes were closed in the middle of an unpractised movement, remained with the extremity in the position it had when the eyes closed and did not complete the movement properly. Then after some oscillations the limb gradually sank by reason of its weight (the sense of fatigue being absent). Of this the patient was not aware, and wondered, when he opened his eyes, at the altered position of his limb." f A similar condition can be readily reproduced experimentally in many hypnotic subjects. All that is needed is to tell a suitably predisposed person during the hypnotic trance that he cannot feel his limb, and he will be quite unaware of the attitudes into which you may throw it.|

All these cases, whether spontaneous or experimental, show the absolute need of guiding sensations of some kind for the successful carrying out of a concatenated series of movements. It is, in fact, easy to see that, just as where the chain of movements is automatic (see above, Vol. I. p. 116), each later movement of the chain has to be discharged by the impression which the next earlier one makes in being * Landry : Memoire sur la Paralysie du Sens Musculaire, Gazette des H6pitaux, 1855, p. 270.

f T^kacs : Ueber die Verspatung der Empfindungaleitung, Archiv ftir Psychiatrie, Bd. x. Heft 2, p. 533. Concerning all such cases see the re marks made above on pp. 205-6. t Proceedings of American Soc. for Psychical Research, p. 95. executed, so also, where the chain is voluntary, we need to know at each movement just wJiere we are in it, if we are to will intelligently what the next link shall be. A man with no feeling of his movements might lead off never so well, and yet be sure to get lost soon and go astray.* But patients like those described, who get no kinsesthetic impressions, can still be guided by the sense of sight Thus Striimpell says of his boy :

"One could always observe how his eye was directed first to the object held before him, then to his own arm; and how it never ceased *In reality the movement cannot even be sCarted correctly in some cases without the kinaesthetic impression. Thus Dr. Striimpell relates how turning over the boy's hand made him bend the little finger instead of the forefinger, when his eye was closed. " Ordered to point, e.g., towards the left with his left arm, the arm was usually raised straight forward, and then wandered about in groping uncertainty, sometimes getting the right position and then leaving it again. Similarly with the lower limbs. If the patient, lying in bed, had, immediately after the tying of his eyes, to lay the left leg over the right, it often happened that he moved it farther over towards the left, and that it lay over the side of the bed in apparently the most intolerably-uncomfortable position. The turning of the head, too, from right to left, or towards certain objects known to the patient, onlj ensued correctly when the patient, immediately befor«3 his eye was bandaged, specially refreshed his perception as to what the required movement was to be." In another anaesthetic of Dr, Strilmpell's (described in the same essay) the arm could not be moved at all unless the eyes were opened, however energetic the volition. The variations in these hysteric cases are great. Some patients cannot move the anaesthetic part at all when the eyes are closed. Others move it perfectly well, and can even write continuous sentences with the anaesthetic hand. The causes of such differences are as yet incompletely unexplored. M. Binet suggests (Revue Philosophique, XXV. 478) that in those who cannot move the hand at all the sensation of light is required as a 'dynamogenic ' agent (see above, p. 377); and that in those who can move it skilfully the anaesthesia is only a pseudo-insensibility and that the limb is in reality governed by a dissociated or secondary consciousness.

This latter explanation is certainly correct. Professor G. E. Mtlller (Pfltiger's Archiv, xlv. 90) invokes the fact of individual differences of imagination to account for the cases who cannot write at all. Their kinaesthetic images properly so called may be weak, he says, and their optical images insuflaciently powerful to supplement them without a * fillip ' from sensation. Janet's observation that hysteric anaesthesias may carry amnesias with them would perfectly legitimate Muller's supposition. What we now want is a minute examination of the individual cases. Meanwhile Binet's article above referred to, and Bastian's paper in Brain for April 1887, contain important discussions of the question. In a later note I shall return to the subject again (see p. 520).

fco follow the latter during its entire movement. All his voluntary movements took place under the unremitting lead of the eye, which aa an indispensable guide, was never untrue to its functions." *' With his eyes open, he easily opposes the thumb to each of the other fingers ; with his eyes closed, the movement of opposition occurs, but the thumb only by chance meets the finger which it seeks. "With his eyes open he is able, without hesitation, to bring his two hands together ; but when his eyes are closed his hands seek one another in space, and only meet by chance."

In Charles Bell's well-known old case of anaesthesia the woman could only hold her baby safely in her arms so long as she looked at it. I have myself reproduced a similar condition in two hypnotic subjects whose arm and hand were made anaesthetic without being paralyzed. They could write their names when looking, but not when their eyes were closed. The modern mode of teaching deaf mutes to articulate consists in making them attentive to certain laryngeal, labial, thoracic, and other sensations, the reproduction of which becomes a guide to their vocalization. Normally it is the remoter sensations which we receive by the ear which keep us from going astray in our speech. The phenomena of aphasia show this to be the usual case."*

This is perhaps all that need be said about the existence of passive sensations of movement and their indispensableness for our voluntary activity. We may consequently set it down as certain that, whether or no there he anything else in the mind at the moment when we consciously will a certain act, a mental conception made up of memory-images of these sensortions, defining which special act it is, must he there. Now is there anything else in the mind ivhen tve wiU to do an act ? We must proceed in this chapter from the simpler to the more complicated cases. My first thesis accordingly is, that there need he nothing else, and that in perfectly simple vol'

* Professor Beaunis found that the accuracy with which a certain tenor sang was not lost when his vocal cords were made anaesthetic by cocain. He concludes that the guiding sensations here are resident in the lar3mge«I muscles themselves. They are much more probably in the ear. (Beaunii^ L«s Sensations Internes (1889), p. untary acts there is nothing else, in the mind but the kincesthetic idea, thus defined, of what the act is to he. A powerful tradition in Psychology will have it that something additional to these images of passive sensation is essential to the mental determination of a voluntary act There must, of course, be a special current of energy going out from the brain into the appropriate muscles during the act ; and this outgoing current (it is supposed) must have in each particular case a feeling sui generis attached to it, or else (it is said) the mind could never tell which particular current, the current to this muscle or the current to that one, was the right one to use. This feeling of the current of outgoing energy has received from Wundt the name of the feeling of innervation. I disbelieve in its existence, and must proceed to criticise the notion of it, at what I fear may to some prove tedious length.

At first sight there is something extremely plausible in the feeling of innervation. The passive feelings of movement with which we have hitherto been dealing all come after the movement's performance. But wherever a movement is difficult and precise, we become, as a matter of fact, acutely aware in advance of the amount and direction of energy which it is to involve. One has only to play tenpins or billiards, or throw a ball, to catch his will in the act, as it were, of balancing tentatively its possible efforts, and ideally rehearsing various muscular contractions nearly correct, until it gets just the right one before it, when it says * Now go ! ' This premonitory weighing feels so much like a succession of tentative sallyings forth of power into the outer world, followed by correction just in time to avoid the irrevocable deed, that the notion that outgoing nervecurrents rather than mere vestiges of former passive sensibility accompany it, is a most natural one to entertain.

We find accordingly that most authors have taken the existence of feelings of innervation as a matter of course. Bain, Wundt, Helmholtz, and Mach defend them most explicitly. But in spite of the authority which such writers deservedly wield, I cannot help thinking that they are in this instance wrong,— that the discharge into the motor nerves is insentient, and that oR our ideas of movement, ineluding those of the effort which it requires, as well as those of its direction, its extent, its strength, and its velocity, are images of peripheral sensations, either ' remote,' or resident in the moving parts, or in other parts which sympathetically act ivith them in consequenceof the * diffusive wave.'

A priori, as I shall show, there is no reason why there should be a consciousness of the motor discharge, and there is a reason why there should not be such a consciousness. The presumption is thus against the existence of the feeling of innervation ; and the burden of proving it falls upon those who believe in it. If the positive empirical evidence which they offer prove also insufficient, then their case falls to the ground, and the feeling in question must be ruled out of court

In the first place, then, let me show that the assumption of the feeling of innervation is unnecessary. I cannot help suspecting that the scholastic prejudice that * the effect must be already in some way contained in the cause ' has had something to do with making psychologists so ready to admit the feeling of innervation. The outgoing current being the effect, what psychic antecedent could contain or prefigure it better than a feeling of it ? But if we take a wide view, and consider the psychic antecedents of our activities at large, we see that the scholastic maxim breaks down everywhere, and that its verification in this instance would rather violate than illustrate the general rule. In the diffusive wave, in reflex action, and in emotional expression, the movements which are the effects are in no manner contained by anticipation in the stimuli which are their cause. The latter are subjective sensations or objective perceptions, which do not in the slightest degree resemble or prefigure the movements. But we get them, and, presto ! there the movements are ! They are knocked out of us, they surprise us. It is just cause for wonder, as our chapter on Instinct has shown us, that such bodily consequences should follow such mental antecedents. We explain the mystery tant hien que mat by our evolutionary theories, saying that lucky variations and heredity have gradually brought it about that

this particular pair of terms should have grown into a uniform sequence. Meanwhile why any state of consciousness at all should precede a movement, we know not — the two things seem so essentially discontinuous. But if a state of consciousness there must be, why then it may, for aught we can see, as easily be one sort of a state as another. It is swallowing a camel and straining at a gnat for a man (all of whose muscles will on certain occasions contract at a sudden touch or sound) to suppose that on another occasion the idea of the feelings about to be produced by their contraction is an insufficient mental signal for the latter, and to insist that an additional antecedent is needed in the shape of * a feeling of the outgoing discharge.*

No ! for aught we can see, and in the light of g«,neral analogy, the kinsesthetic ideas, as we have defined them, or images of incoming feelings of attitude and motion, are as likely as any feelings of innervation are, to be the last psychic antecedents and determiners of the various currents downwards into the muscles from the brain. The question " What are the antecedents and determinants ?" is a question of fact, to be decided by whatever empirical evidence may be found.*

* As the feeling of heat, for example, is the last psychic antecedent of sweating, as the feeling of bright light is that of the pupil's contraction, as the sight or smell of carrion is that of the movements of disgust, as the remembrance of a blunder may be that of a blush, so the idea of a movement's sensible effects might be that of the movement itself. It is true that the idea of sweating will not commonly make us sweat, nor that of blushing make us blush. But in certain nauseated states the idea of vomiting will make us vomit; and a' kind of sequence which is in this case realized only exceptionally might be the rule with the so-called voluntary muscles It all depends on the nervous connections between the centres of ideation and the discharging paths. These may differ from one sort of centre to another. They do differ somewhat from one individual to another. Many persons never blush at the idea of their blunders, but only when the actual blunder is committed; others blush at the idea; and somo do not blush at all. According to Lotze, with some persons " It is possible to weep at will by trying to recall that peculiar feeling in the trigeminal nerve which habitually precedes tears. Some can even succeed in sweating voluntarily, by the lively recollection of the characteristic skin-sensations, and the voluntary reproduction of an indescribable sort of feeling of relaxation, which ordinarily precedes the flow of perspiration." (Med. Psych., p. 303.) The commoner type of exceptional case is that in which the idea of the 9timulu8, not that of the effects, provokes the effects. Thus w«

But before considering the empirical evidence, let me go on to show that there is a certain a priori reason why the kincesthetic images ought to be the last psychic antecedents oj the outgoing currents^ and why we shovld expect these currents to he insentient; why, in short, the soi-disant feelings of innervation shovM NOT exist. It is a general principle in Psychology that consciousaess deserts all processes where it can no longer be of use. The tendency of consciousness to a minimum of complication is in fact a dominating law. The law of parsimony in logic is only its best known casco We grow unconscious of every feeling which is useless as a sign to lead us to our ends, and where one sign will suffice others drop out, and that one remains, to work alone. We observe this in the whole history of sense-perception, and in the acquisition of every art. We ignore which eye we see with, because a fixed mechanical association has been formed between our motions and each retinal image. Our motions are the ends of our seeing, our retinal images the signals to these ends. If each retinal image, whichever it be, can suggest automatically a motion in the right direction, what need for us to know whether it be in the right eye or the left ?

read of persons who contract their pupils at will by strongly imagining a brilliant light. A gentleman once informed me (strangely enough I cannot recall who he was, but I have an impression of his being a medical man) that he could sweat at will by imagining himself on the brink of a precipice. The sweating palms of fear are sometimes producible by imagining a terrible object (cf. Manouvrier in Rev. Phil., xxii. 203). One of my students, whose eyes were made to water by sitting in the dentist's chair before a bright window, can now shed tears by imagining that situation again. One might doubtless collect a large number of idiosyncratic cases of this sort. They teach us how greatly the centres vary in their power to discharge through certain channels. All that we need, now, to account for the differences observed between the psychic antecedents of the voluntary and involuntary movements is that centres producing ideas of the movement's sensible effects should be able to instigate the former, but be out of gear with the latter, unless in exceptional individuals. The famous case of Col. Townsend, who could stop his heart at will, is well known. See, on this whole matter, D. H. Tuke: Illustrations of the Influence of the Mind on the Body, chap. xiv. § 3; also J. Braid: Observations on Trance or Human Hybernation (1850). The latest reported case of voluntary control of the heart is by Dr. S. A. Pease, in Boston Medical and Surgical Journal, May 30, 1889.

That knowledge would be superfluous complication. So in acquiring any art or voluntary function. The marksman ends by thinking only of the exact position of the goal, the singer only of the perfect sound, the balancer only of the point of the pole whose oscillations he must counteract. The associated mechanism has become so perfect in all these persons that each variation in the thought of the end is functionally correlated with the one movement fitted to bring the latter about. Whilst they were tyros, they thought of their means as well as their end: the marksman of the position of his gun or bow, or the weight of his stone ; the pianist of the visible position of the note on the keyboard ; the singer of his throat or breathing ; the balancer of his feet on the rope, or his hand or chin under the pole. But little by little they succeeded in dropping all this supernumerary consciousness, and they became secure in their movements exactly in proportion as they did so.

Now if we analyze the nervous mechanism of voluntary action, we shall see that by virtue of this principle of parsimony in consciousness the motor discharge ought to be devoid of sentience. If we call the immediate psychic antecedent of a movement the latter's mental cm, all that is needed for invariability of sequence on the movement's part is 2, fixed connection between each several mental cue, and one particular movement. For a movement to be produced with perfect precision, it suffices that it obey instantly its own mental cue and nothing else, and that this mental cue be incapable of awakening any other movement. Now the simplest possible arrangement for producing voluntary movements would be that the memory-images of the movement's distinctive peripheral effects, whether resident or remote,* themselves should severally constitute the mental cues, and that no other psychic facts should intervene or be mixed up with them. For a million different voluntary movements, we should then need a million dis-

* Prof. Harless, in an article which in many respects forestalls what 1 have to say (Der Apparat des Willens, in Fichte's Zeitschrift f. Philos., Bd. 38, 1861), uses the convenient word Effectsbild to designate these images. tinct processes in the brain-cortex (each corresponding tv) the idea or memory-image of one movement), and a million distinct paths of discharge. Everything would then be unambiguously determined, and if the idea were right, the movement would be right too. Everything after the idea might then be quite insentient, and the motor discharge itself could be unconsciously performed.

The partisans of the feeling of innervation, however, say that the motor discharge itself must be felt, and that it, and not the idea of the movement's distinctive effects, must be the proper mental cue. Thus the principle of parsimony is sacrificed, and all economy and simplicity are lost. For what can be gained by the interposition of this relay of feeling between the idea of the movement and the movement ? Nothing on the score of economy of nervetracts ; for it takes just as many of them to associate a million ideas of movement with a million motor centres, each with a specific feeling of innervation attached to its discharge, as to associate the same million ideas with a million insentient motor centres. And nothing on the score of precision ; for the only conceivable way in which the feelings of innervation might further precision would be by giving to a mind whose idea of a movement was vague, a sort of halting stage with sharper imagery on which to collect its wits before uttering its^a^. But not only are the conscious discriminations between our kingesthetic ideas much sharper than any one pretends the shades of difference between feelings of innervation to be, but even were this not the case, it is impossible to see how a mind with its idea vaguely conceived could tell out of a lot of InnervationsgefvMe^ were they never so sharply differentiated, which one fitted that idea exactly, and which did not. A sharply conceived idea will, on the other hand, directly awaken a distinct movement as easily as it will awaken a distinct feeling of innervation. If feelings can go astray through vagueness, surely the fewer steps of feeling there are interposed the more securely we shall act.

We ought then, on a priori grounds alone, to regard the InnervationsgefilM as a pure encumbrance, and to presume that the peripheral ideas of movement are sufficient mental cues. The presumption being thus against the feelings of innervation, those who defend their existence are bound to prove it by positive evidence. The evidence might be direct or indirect. If we could introspectively feel them as something plainly distinct from the peripheral feelings and ideas of movement which nobody denies to be there, that would be evidence both direct and conclusive. Unfortunately it does not exist.

There is no introspective evidence of the feeling of innervation. Wherever we look for it and think we have grasped it, we find that we have really got a peripheral feeling or image instead — an image of the way in which we feel when the innervation is over, and the movement is in process of doing or is done. Our idea of raising our arm, for example, or of crooking our finger, is a sense, more or less vivid, of how the raised arm or the crooked finger feels. There is no other mental material out of which such an idea might be made. We cannot possibly have any idea of our ears* motion until our ears have moved ; and this is true of every other organ as well.

Since the time of Hume it has been a commonplace in psychology that we are only conversant with the outward results of our volition, and not with the hidden inner machinery of nerves and muscles which are what it primarily sets at work.* The believers in the feeling of innervation readily admit this, but seem hardly alive to its consequences. It seems to me that one immediate consequence ought to be to make us doubt the existence of the feeling in dispute. Whoever says that in raising his arm he is ignorant of how many muscles he contracts, in what order of sequence, and in what degrees of intensity, expressively avows a colossal amount of unconsciousness of the processes of motor discharge. Each separate muscle at any rate cannot have its distinct feeling of innervation. Wundtjt who makes such enormous use of these hypo-

* The best modern statement I know is by Jaccoud: Des Paraplegies et de I'Ataxie du Mouvement (Paris, 1864), p. 591. thetical feelings in his psychologic construction of space, ia himself led to admit that they have no diiferences of quality, but feel alike in all muscles, and vary only in their degrees of intensity. They are used by the mind as guides, not of tuhich movement, but of Jiow strong a movement, it is making, or shall make. But does not this virtually surrender their existence altogether ? *

For if anything be obvious to introspection it is that the degree of strength of our muscular contractions is completely revealed to us by afferent feelings coming from the muscles themselves and their insertions, from the vicinity of the joints, and from the general fixation of the larynx, chest, face, and body, in the phenomenon of effort, objectively considered. When a certain degree of energy of contraction rather than another is thought of by us, this complex aggregate of afferent feelings, forming the material of our thought, renders absolutely precise and distinctive our mental image of the exact strength of movement to be made, and the exact amount of resistance to be overcome.

Let the reader try to direct his will towards a particular movement, and then notice what constituted the direction of the will. Was it anything over and above the notion of the different feelings to which the movement when effected would give rise ? If we abstract from these feelings, will any sign, principle, or means of orientation be left by which the will may innervate the right muscles with the right intensity, and not go astray into the wrong ones? Strip off these images of result, and so far from leaving us with a complete assortment of directions into which our will may launch itself, you leave our consciousness in an absolute and total vacuum. If I will to write "Peter" rather than "Paul," it is the thought of certain digital sensations, of certain alphabetic sounds, of certain appearances on the paper, and of no others, which immediately precedes the motion of my pen.

* Professor Fouillee, who defends them in the Revue Philosophique- XXVIII, 561 ff.. also admits (p. 574) that they are the same whatever be thf movement, and that all our discrimination of which movement we are innervating is afferent, consisting of sensations after, and of sensory images before, the act If I will to utter the word Pavl rather than PeteVy it is the thought of my voice falling on my ear, and of certain muscular feelings in my tongue, lips, and larynx, which guide the utterance. All these are incoming feelings, and between the thought of them, by which the act is mentally specified with all possible completeness, and the act itself, there is no room for any third order of mental phenomenon. There is indeed the fiat^ the element of consent, or resolve that the act shall ensue. This, doubtless, to the reader's mind, as to my own, constitutes the essence of the voluntariness of the act. This Jiat will be treated of in detail farther on. It may be entirely neglected here, for it is a constant coefl&cient, affecting all voluntary actions alike, and incapable of serving to distinguish them. No one will pretend that its quality varies according as the right arm, for example, or the left is used.

An anticipatory imager ihen^ of the sensorial consequences of a movement, plvs {on certain occasions) the fiat that these consequences shall become actual, is the only psychic state which introspection lets us discern as the forerunner of our voluntary acts. There is no introspective evidence whatever of any still later or concomitant feeling attached to the efferent discharge. The various degrees of difficulty with which the fiat is given form a complication of the utmost importance, to be discussed farther on.