The Principles of Psychology, Vols. 1-2

" In a discourse of our present civil war, what could seem more im pertinent than to ask (as one did) what was the value of a Roman penny? Yet the coherence to me was manifest enough. For the thought of the war introduced the thought of the delivering up' the King to his enemies; the thought of that brought in the thought of the delivering up of Christ; and that again the thought of the thirty pence, which was the price of that treason: and thence easily followed that malicious question; and all this in a moment of time; for thought is quick."*

Can we determine, now, when a certain portion of the going thought has, by dint of its interest, become so pre potent as to make its own exclusive associates the dominant features of the coming thought — can we, I say, determine ivhich of its own associates shall be evoked ? For they are many. As Hodgson says : " The interesting parts of the decaying object are free to combine again with any objects or parts of objects with which at any time they have been combined before. All the former combinations of these parts may come back into consciousness; one must; but which will?"

" There can be but one answer : that which has been most habitually combined with them before. This new object begins at once to form itself in consciousness, and to group its parts round the part still re maining from the former object; part after part comes out and arranges I itself in its old position ; but scarcely has the process begun, when the I original law of interest begins to operate on this new formation, seizes 1 on the interesting parts and impresses them on the attention to the ex clusion of the rest, and the whole process is repeated again with end less variety. I venture to propose this as a complete and true account of the whole process of redintegration."

In restricting the discharge from the interesting item into that channel which is simply most habitual in the sense of most frequent, Hodgson's account is assuredly imperfect. An image by no means always revives its most frequent associate, although frequency is certainly one of the most potent determinants of revival. If I abruptly utter the word swallow, the reader, if by habit an ornithologist, will think of a bird ; if a physiologist or a medical specialist in throat diseases, he will think of deglutition. If I say date,

he will, if a fruit-merchant or an Arabian traveller, think of the produce of the palm ; if an habitual student of history, figures with A.D. or B.C. before them will rise in his mind. If I say bed, bath, morning, his own daily toilet will be in- ! vincibly suggested by the combined names of three of its habitual associates. But frequent lines of transition are often set at naught. The sight of C. Goring' s 'System derv kritischen Philosophic ' has most frequently awakened in \ v me thoughts of the opinions therein propounded. The idea of suicide has never been connected with the volumes. But a moment since, as my eye fell upon them, suicide was the thought that flashed into my mind. Why ? Because but yesterday I received a letter from Leipzig informing me . that this philosopher's recent death by drowning was an act of self-destruction. Thoughts tend, then, to awaken their most recent as well as their most habitual associates. This is a matter of notorious experience, too notorious, in fact, to need illustration. If we have seen our friend this morning, the mention of his name now recalls the circum stances of that interview, rather than any more remote details concerning him. If Shakespeare's plays are men tioned, and we were last night reading ' Richard II.,' ves tiges of that play rather than of ' Hamlet ' or ' Othello ' float through our mind. Excitement of peculiar tracts, or peculiar modes of general excitement in the brain, leave a sort of tenderness or exalted sensibility behind them which takes days to die away. As long as it lasts, those tracts or those modes are liable to have their activities awakened by causes which at other times might leave them in repose. Hence, recency in experience is a prime factor in determining revival in thought.*

Vividness in an original experience may also have the same effect as habit or recency in bringing about likelihood of revival. If we have once witnessed an execution, any subsequent conversation or reading about capital punish ment will almost certainly suggest images of that particular * I refer to a recency of a few hours. Mr. Galton found that experi ences from boyhood and youth were more likely to be suggested by words seen at random than experiences of later years. See his highly interesting account of experiments in his Inquiries into Human Faculty, pp. 1

scene. Thus it is that events lived through only once, and in youth, may come in after-years, by reason of their excit ing quality or emotional intensity, to serve as types or instances used by our mind to illustrate any and every occurring topic Avhose interest is most remotely pertinent to theirs. If a man in his boyhood once talked with Napo leon, any mention of great men or historical events, battles or thrones, or the whirligig of fortune, or islands in the ocean, will be apt to draw to his lips the incidents of that one memorable interview. If the word tooth now suddenly appears on the page before the reader's eye, there are fifty

•, chances out of a hundred that, if he gives it time to awaken any image, it will be an image of some operation of den tistry in which he has been the sufferer. Daily he has touched his teeth and masticated with them ; this very morning he brushed them, chewed his breakfast and picked them ; but the rarer and remoter associations arise more promptly because they were so much more intense.* A fourth factor in tracing the course of reproduction is congruity in emotional tone between the reproduced idea and our mood. The same objects do not recall the same asso ciates when we are cheerful as when we are melancholy. Nothing, in fact, is more striking than our utter inability to keep up trains of joyous imagery when we are depressed in spirits. Storm, darkness, war, images of disease, poverty,

I and perishing afflict unremittingly the imaginations of melancholiacs. And those of sanguine temperament, when their spirits are high, find it impossible to give any permanence to evil forebodings or to gloomy thoughts. In an instant the train of association dances off to flowers and sunshine, and images of spring and hope. The records of Arctic or African travel perused in one mood awaken no thoughts but those of horror at the malignity of Nature; read at

: another time they suggest only enthusiastic reflections on \ the indomitable power and pluck of man. Few novels so overflow with joyous animal spirits as ' The Three Guards men' of Dumas. Yet it may awaken in the mind of a *For other instances see Wahle, in Vierteljsch f. Wiss. Phil., ix. 144- reader depressed with sea-sickness (as the writer can per sonally testify) a most dismal and woful consciousness of the cruelty and carnage of which heroes like Athos, Porthos, and Aramis make themselves guilty.

Habit, recency, vividness, and emotional congruity are, then, } \f all reasons why one representation rather than another should be awakened by the interesting portion of a departkig thought. We may say with truth that in the majority of cases the coming representation ivill have been either habitual, recent, or vivid, and ivill be congruous. If all these qualities unite in any one absent associate, we may predict almost infallibly that that associate of the going thought will form an important ingredient in the coming thought. In spite of the fact, however, that the succession of representations is thus redeemed from perfect indeterminism and limited to a few classes whose characteristic quality is fixed by the nature of our past experience, it must still be confessed that an immense number of terms in the linked chain of our representations fall outside of all assignable rule. To take the instance of the clock given on page 586. Why did the jeweller's shop suggest the shirtstuds rather than a chain which I had bought there more recently, which had cost more, and whose sentimental as sociations were much more interesting? Both chain and studs had excited brain-tracts simultaneously with the shop. The only reason why the nerve-stream from the shop-tract switched off into the stud-tract rather than into the chaintract must be that the stud-tract happened at that moment to lie more open, either because of some accidental alteration in its nutrition or because the incipient sub-conscious tensions of the brain as a whole had so distributed their equilibrium that it was more unstable here than in the chain-tract. Any reader's introspection will easily furnish similar in stances.

It thus remains true that to a certain extent, even in those forms of ordinary mixed association whic-h lie nearest to impartial redintegration, which associate of the interesting item shall emerge must be called largely a mat-) ter of accident — accident, that is, for our intelligence. No doubt it is determined by cerebral causes, but they are too subtile and shifting for our analysis, In partial or mixed association we have all along sup posed the interesting portion of the disappearing thought ! to be of considerable extent, and to be sufficiently com plex to constitute by itself a concrete object. Sir Wil liam Hamilton relates, for instance, that after thinking of Ben Lomond he found himself thinking of the Prussian system of education, and discovered that the links of asso ciation were a German gentleman whom he had met on Ben Lomond, Germany, etc. The interesting part of Ben Lomond, as he had experienced it, the part operative in determining the train of his ideas was the complex image of a particular man. But now let us suppose that that selective agency of interested attention, which may thus convert impartial redintegration into partial association — • let us suppose that it refines itself still further and accen tuates a portion of the passing thought, so small as to be no longer the image of a concrete thing, but only of an abstract quality or property. Let us moreover suppose that the part thus accentuated persists in consciousness (or, in cerebral terms, has its brain-process continue) after the other portions of the thought have faded. This small sur viving portion ivill then surround itself with its own associates after the fashion we have already seen, and the relation between the new thought's object and the object of the faded thought will be a relation of similarity. The pair of thoughts will form an instance of what is called ' Associa tion by Similarity.'' *

The similars which are here associated, or of which the first is followed by the second in the mind, are seen to be compounds. Experience proves that this is always the *I retain the title of association by similarity in order not to depart from common usage. The reader will observe, however, that my nomen clature is not based on the same principle throughoiit. Impartial redinte gration connotes neiiral processes ; similarity is an objective relation per ceived by the mind ; ordinary or mixed association is a merely denotative word. Total recall, partial recall, and focalized recall, of associates, would be better terms. But as the denotation of the latter word is almost identical with that of association by similarity, 1 think it better to sacrifice propriety to popularity, and to keep the latter well-worn phrase.

case. There is no tendency on the part of SIMPLE * ideas,' attri butes, or qualities to remind us of their like. The thought of one shade of blue does not remind us of that of another shade of blue, etc., unless indeed we have in mind some general purpose like naming the tint, when we should naturally think of other blues of the scale, through ' mixed association' of purpose, names, and tints, together. But there is no elementary tendency of pure qualities to awaken their similars in the mind.

We saw in the chapter on Discrimination that two com pound things are similar when some one quality or group of qualities is shared alike by both, although as regards their other qualities they may have nothing in common. The moon is similar to a gas-jet, it is also similar to a foot ball ; but a gas-jet and a foot-ball are not similar to each other. When we affirm the similarity of two compound things, we should always say in wind respect it obtains. Moon and gas-jet are similar in respect of luminosity, and nothing else ; moon and foot-ball in respect of ro tundity, and nothing else. Foot-ball and gas-jet are in no respect similar — that is, they possess no common point, no identical attribute. Similarity, in compounds, is partial identity. When the same attribute appears in two phenomena, though it be their only common property, the two phenomena are similar in so far forth. To return now to our associated representations. If the thought of the moon is succeeded by the thought of a foot-ball, and that by the thought of one of Mr. X's railroads, it is because the attribute rotundity in the moon broke away from all the rest and surrounded itself with an entirely new set of com panions—elasticity, leathery integument, swift mobility m obedience to human caprice, etc. ; and because the lastnamed attribute in the foot-ball in turn broke away from its companions, and, itself persisting, surrounded itself with such new attributes as make up the notions of a ' railroad king,' of a rising and falling stock-market, and the like.

The gradual passage from impartial redintegration to similar association through what we have called ordinary mixed association may be symbolized by diagrams. Fig. 41 is impartial redintegration, Fig. 42 is mixed, and Fig. 4H similar association. A in each is the passing, B the coming thought. In 'impartial,' all parts of A are equally operative in calling up B. In * mixed,' most parts of A are inert The part M alone breaks out and awakens B. In ' similar,' the focalized part M is much smaller than in the previous

case, and after awakening its new set of associates, instead of fading out itself, it continues persistently active along with them, forming an identical part in the two ideas, and making these, pro tanto, resemble each other. Why a single portion of the passing thought should break out from its concert with the rest and act, as we say, on its own hook, why the other parts should become inert, are mysteries which we can ascertain but not explain. Pos sibly a minuter insight into the laws of neural action will

some day clear the matter up ; possibly neural laws will not suffice, and we shall need to invoke a dynamic reaction of the form of consciousness upon its content. But into this we cannot enter now. To ^sum up, then, we see that the difference between the three kinds of association reduces itself to d simple difference in the amount of that portion of the nerve-tract supporting tha going thought ivhich is operative in calling up the thought which comes. But the modus operandi of this active part is the same, be it large or be it small. The items constituting the coming object waken in every instance because theii nerve-tracts once were excited continuously with those ol the going object or its operative part. This ultimate physio logical law of habit among the neural elements is what runs the train. The direction of its course and the form of its transitions, whether redintegrate, associative, or similar, are due to unknown regulative or determinative conditions which accomplish their effect by opening this switch and closing that, setting the engine sometimes at half-speed, and coupling or uncoupling cars.

This last figure of speech, into which I have glided un wittingly, affords itself an excellent instance of association by similarity. I was thinking of the deflections of the course of ideas. Now, from Hobbes's time downward, English writers have been fond of speaking of the train of our representations. This word happened to stand out in the midst of my complex thought Avith peculiarly sharp accentuation, and to surround itself with numerous details of railroad imagery. Only such details became clear, how ever, as had their nerve-tracts besieged by a double set of influences — those from train on the one hand, and those from the movement of thought en the other. It may possibly be that the prepotency of the suggestions of the word train at this moment were due to the recent excitation of the rail road brain-tract by the instance chosen a few pages back of a, railroad king playing football with the stock-market.

It is apparent from such an example how inextricably complex are all the contributory factors whose resultant is the line of our reverie. It would be folly in most cases to attempt to trace them out. From an instance like the above, where the pivot of the Similar Association was formed by a definite concrete word, train, to those where it is so subtile as utterly to elude our analysis, the passage is unbroken. We can form a series of examples. When Mr. Bagehot says that the mind of the savage, so far from being in a state of nature, is tattooed all over with monstrous superstitions, the case is very like the one we have just been considering. When Sir James Stephen compares our belief in the uni formity of nature, the congruity of the future with the past, to a man rowing one way and looking another, and steering his boat by keeping her stern in a line with an object behind him, the operative link becomes harder to dissect out. It is subtler still in Dr. Holmes's phrase, that stories in pass ing from mouth to mouth make a great deal of lee-way in proportion to their headway ; or in Mr. Lowell's descrip tion of German sentences, that they have a way of yawing and going stern-foremost and not minding the helm for sev eral minutes after it has been put down. And finally, it is a real puzzle when the color pale-blue is said to have femi nine and blood-red masculine affinities. And if I hear a friend describe a certain family as having blotting-paper voices, the image, though immediately felt to be appo site, baffies the utmost powers of analysis. The higher poets all use abrupt epithets, which are alike intimate and remote, and, as Emerson says, sweetly torment us with in vitations to their inaccessible homes.

In these latter instances we must suppose that there is an identical portion in the similar objects, and that its braintract is energetically operative, without, however, being suffi ciently isolable in its activity as to stand out per se, and form the condition of a distinctly discriminated 'abstract idea.' We cannot even by careful search see the bridge over which we passed from the heart of one representation to that of the next. In some brains, however, this mode of transition is extremely common. It would be one of the most impor tant of physiological discoveries could we assign the me chanical or chemical difference which makes the thoughts of one brain cling close to impartial redintegration, while those of another shoot about in all the lawless revelry of

similarity. Why, in these latter brains, action should tend to focalize itself in small spots, while in the others it fills patiently its broad bed, it seems impossible to guess. Whatever the difference may be, it is what separates the man of genius from the prosaic creature of habit and rou tine thinking. In Chapter XXII we shall need to recur again to this point. Hitherto we have assumed the process of suggestion of one object by another to be spontaneous. The train of imagery wanders at its own sweet will, now trudging in sober grooves of habit, now with a hop, skip, and jump darting across the whole field of time and space. This is revery, or musing ; but great segments of the fiux of our ideas consist of something very different from this. They are guided by a distinct purpose or conscious interest. As the Germans say, we nachdenken, or think towards a certain end. It is now necessary to examine what modification is made in the trains of our imagery by the having of an end in view. The course of our ideas is then called voluntary.

Physiologically considered, we must suppose that a purpose means the persistent activity of certain rather definite brain-processes throughout the whole course of thought. Our most usual cogitations are not pure reveries, absolute driftings, but revolve about some central interest or topic to which most of the images are relevant, and to wards which we return promptly after occasional digres sions. This interest is subserved by the persistently active brain-tracts we have supposed. In the mixed associations which we have hitherto studied, the parts of each object which form the pivots on which our thoughts successively turn have their interest largely determined by their con nection with some general interest which for the time has seized upon the mind. If we call Z the brain-tract of gen eral interest, then, if the object abc turns up, and b has more associations with Z than have either a or c, b will be come the object's interesting, pivotal portion, and will call up its own associates exclusively. For the energy of 6's braintract will be augmented by Z's activity, — an activity which,

from lack of previous connection between Z and a or c, does not influence a or c. If, for instance, I think of Paris whilst I am hungry, I shall not improbably find that its restaurants have become the pivot of my thought, etc., etc. But in the theoretic as well as in the practical life there are interests of a more acute sort, taking the form of defi nite images of some achievement, be it action or acquisition; which we desire to effect. The train of ideas arising under the influence of such an interest constitutes usually the thought of the means by which the end shall be attained. If the end by its simple presence does not instantaneously suggest the means, the search for the latter becomes an in tellectual problem. The solution of problems is the most characteristic and peculiar sort of voluntary thinking. Where the end thought of is some outward deed or gain, the solution is largely composed of the actual motor pro cesses, walking, speaking, writing, etc., which lead up to it. Where the end is in the first instance only ideal, as in lay ing out a place of operations, the steps are purely imagi nary. In both of these cases the discovery of the means may form a new sort of end, of an entirely peculiar nature, an end, namely, which we intensely desire before we have attained it, but of the nature of which, even whilst most strongly craving it, we have no distinct imagination what ever. Such an end is a problem.

The same state of things occurs whenever we seek to recall something forgotten, or to state the reason for a judgment which we have made intuitively. The desire strains and presses in a direction which it feels to be right but towards a point which it is unable to see. In short, the absence of an item is a determinant of our representa tions quite as positive as its presence can ever be. The gap becomes no mere void, but what is called an aching void. If we try to explain in terms of brain-action how a thought which only potentially exists can yet be effective, we seem driven to believe that the brain-tract thereof must actually be excited, but only in a minimal and sub-con scious way. Try, for instance, to symbolize what goes on in a man who is racking his brains to remember a thought which occurred to him last week. The associates of the

thought are there, many of them at least, but they refuse to awaken the thought itself. We cannot suppose that they do not irradiate at all into its brain-tract, because his mind quivers on the very edge of its recovery. Its actual rhythm sounds in his ears ; the words seem on the imminent point of following, but fail. What it is that blocks the discharge and keeps the brain-excitement here from passing beyond the nascent into the vivid state cannot be guessed. But we see in the philosophy of desire and pleasure, that such nas cent excitements, spontaneously tending to a crescendo, but inhibited or checked by other causes, may become potent mental stimuli and determinants of desire. All questioning, wonder, emotion of curiosity, must be referred to cerebral causes of some such form as this. The great difference between the effort to recall things forgotten and the search after the means to a given end, is that the latter have not, whilst the former have, already formed a part of our experience. If we first study the mode of recalling a thing forgotten, we can take up with better understanding the voluntary quest of the unknown.

The forgotten thing is felt by us as a gap in the midst of certain other things. If it is a thought, we possess a dim idea of where we were and what we were about when it oc curred to us. We recollect the general subject to which it relates. But all these details refuse to shoot together into a solid whole, for the lack of the vivid traits of this missing thought, the relation whereof io each detail forms now the main interest of the latter. We keep running over the de tails in our mind, dissatisfied, craving something more. Prom each detail there radiate lines of association forming so many tentative guesses. Many of these are immediately seen to be irrelevant, are therefore void of interest, and lapse immediately from consciousness. Others are asso ciated with the other details present, and with the missing thought as well. When these surge up, we have a peculiar feeling that we are ' warm,' as the children say when they play hide and seek ; and such associates as these we clutch at and keep before the attention. Thus we recollect suc cessively that when we had the thought in question we were at the dinner-table ; then that our friend J. D. was

there ; then that the subject talked about was so and so , finally, that the thought came d propos of a certain anecdote, and then that it had something to do with a French quota tion. Now all these added associations arise independently of the will, by the spontaneous process we know so well. All that the will does is to emphasize and linger over those ivhich seem pertinent, and ignore the rest. Through this hovering of the attention in the neighborhood of the desired object, the accumulation of associates becomes so great that the com bined tensions of their neural processes break through the bar, and the nervous wave pours into the tract v/hicli has so long been awaiting its advent. And as the expectant, sub-conscious itching there, bursts into the fulness of vivid feeling, the mind finds an inexpressible relief.

The whole process can be rudely symbolized in a dia gram. Call the forgotten thing Z, the first facts with which we felt it was related, a, b, and c, and the details finally operative in calling it up, I, m, and n. Each circle will then stand for the brain-process underlying the thought of the object denoted by the letter contained within it. The activity in Z will at first be a mere tension ; but as the ac tivities in a, b, and c little by little irradiate into ly m, and n,

and as all these processes are somehow connected with Z, their combined irradiations upon Z, represented by the cen tripetal arrows, succeed in helping the tension there to overcome the resistance, and in rousing Z also to full ac tivity. The tension present from the first in Z, even though it keep below the threshold of discharge, is probably to some degree co-operative with a, b, c in determining that I, m, n shall awake. Without Z's tension there might be a slower accumulation of objects connected with it. But, as aforesaid, the objects come before us through the brain's own laws, and the Ego of the thinker can only remain on hand, as it were, to recognize their relative values and brood over some of them, whilst others are let drop. As when we have lost a material object we cannot recover it by a direct ef fort, but only through moving about such neighborhoods wherein it is likely to lie, and trusting that it will then strike our eye ; so here, by not letting our attention leave the neighborhood of what we seek, we trust that it will end by speaking to us of its own accord.*