The Principles of Psychology, Volume 1 · William James
THE ELEMENTARY LAW OF ASSOCIATION.
I shall try to show, in the pages which immediately follow, that there is no other _elementary_ causal law of association than the law of neural habit. All the _materials_ of our thought are due to the way in which one elementary process of the cerebral hemispheres tends to excite whatever other elementary process it may have excited at some former time. The number of elementary processes at work, however, and the nature of those which at any time are fully effective in rousing the others, determine the character of the total brain-action, and, as a consequence of this, they determine the object thought of at the time. According as this resultant object is one thing or another, we call it a product of association by contiguity or of association by similarity, or contrast, or whatever other sorts we may have recognized as ultimate. Its production, however, is, in each one of these cases, to be explained by a merely quantitative variation in the elementary brain-processes momentarily at work under the law of habit, so that _psychic_ contiguity, similarity, etc., are derivatives of a single profounder kind of fact. My thesis, stated thus briefly, will soon become more clear; and at the same time certain disturbing factors, which co-operate with the law of neural habit, will come to view. Let us then assume as the _basis_ of all our subsequent reasoning this law: _When two elementary brain-processes have been active together or in immediate succession, one of them, on reoccurring, tends to propagate its excitement into the other._
But, as a matter of fact, every elementary process has found itself at different times excited in conjunction with _many_ other processes, and this by unavoidable outward causes. Which of these others it shall awaken now becomes a problem. Shall _b_ or _c_ be aroused next by the present _a_? We must make a further postulate, based, however, on the fact of _tension_ in nerve-tissue, and on the fact of summation of excitements, each incomplete or latent in itself, into an open resultant.[478] The process _b_, rather than _c_, will awake, if in addition to the vibrating tract _a_ some other tract _d_ is in a state of sub-excitement, and formerly was excited with _b_ alone and not with _a_. In short, we may say: _The amount of activity at any given point in the brain-cortex is the sum of the tendencies of all other points to discharge into it, such tendencies being proportionate_ (1) _to the number of times the excitement of each other point may have accompanied that of the point in question_; (2) _to the intensity of such excitements; and_ (3) _to the absence of any rival point functionally disconnected with the first point, into which the discharges might be diverted._ Expressing the fundamental law in this most complicated way leads to the greatest ultimate simplification. Let us, for the present, only treat of spontaneous trains of thought and ideation, such as occur in revery or musing. The case of voluntary thinking toward a certain end shall come up later.
Take, to fix our ideas, the two verses from 'Locksley Hall': "I, the heir of all _the ages_ in the foremost files of time," and-- "For I doubt not through _the ages_ one increasing purpose runs." Why is it that when we recite from memory one of these lines, and get as far as _the ages_, that portion of the _other_ line which follows, and, so to speak, sprouts out of _the ages_, does not also sprout out of our memory, and confuse the sense of our words? Simply because the word that follows _the ages_ has its brain-process awakened not simply by the brain-process of _the ages_ alone, but by it _plus_ the brain-processes of all the words preceding _the ages_. The word _ages_ at its moment of strongest activity would, _per se_, indifferently discharge into either 'in' or 'one.' So would the previous words (whose tension is momentarily much less strong than that of _ages_) each of them indifferently discharge into either of a large number of other words with which they have been at different times combined. But when the processes of '_I, the heir of all the ages_,' simultaneously vibrate in the brain, the last one of them in a maximal, the others in a fading phase of excitement; then the strongest line of discharge will be that which they _all alike_ tend to take. '_In_' and not '_one_' or any other word will be the next to awaken, for its brain-process has previously vibrated in unison not only with that of _ages_, but with that of all those other words whose activity is dying away. It is a good case of the effectiveness over thought of what we called on p. 258 a 'fringe.'
But if some one of these preceding words--'heir,' for example--had an intensely strong association with some brain-tracts entirely disjoined in experience from the poem of 'Locksley Hall'--if the reciter, for instance, were tremulously awaiting the opening of a will which might make him a millionaire--it is probable that the path of discharge through the words of the poem would be suddenly interrupted at the word 'heir.' His _emotional interest in that word_ would be such that its _own special associations would prevail_ over the combined ones of the other words. He would, as we say, be abruptly reminded of his personal situation, and the poem would lapse altogether from his thoughts. The writer of these pages has every year to learn the names of a large number of students who sit in alphabetical order in a lecture-room. He finally learns to call them by name, as they sit in their accustomed places. On meeting one in the street, however, early in the year, the face hardly ever recalls the name, but it may recall the place of its owner in the lecture-room, his neighbors' faces, and consequently his general alphabetical position; and then, usually as the common associate of all these combined data, the student's name surges up in his mind.
A father wishes to show to some guests the progress of his rather dull child in Kindergarten instruction. Holding the knife upright on the table, he says, "What do you call that, my boy?" "I calls it a _knife_, I does," is the sturdy reply, from which the child cannot be induced to swerve by any alteration in the form of question, until the father recollecting that in the Kindergarten a pencil was used, and not a knife, draws a long one from his pocket, holds it in the same way, and then gets the wished-for answer, "I calls it _vertical_." All the concomitants of the Kindergarten experience had to recombine their effect before the word 'vertical' could be reawakened. Professor Bain, in his chapters on 'Compound Association,' has treated in a minute and exhaustive way of this type of mental sequence, and what he has done so well need not be here repeated.[479] _Impartial Redintegration._
The ideal working of the law of compound association, were it unmodified by any extraneous influence, would be such as to keep the mind in a perpetual treadmill of concrete reminiscences from which no detail could be omitted. Suppose, for example, we begin by thinking of a certain dinner-party. The only thing which all the components of the dinner-party could combine to recall would be the first concrete occurrence which ensued upon it. All the details of this occurrence could in turn only combine to awaken the next following occurrence, and so on. If _a, b, c, d, e,_ for instance, be the elementary nerve-tracts excited by the last act of the dinner-party, call this act A, and _l, m, n, o, p,_ be those of walking home through the frosty night, which we may call B, then the thought of A must awaken that of B, because _a, b, c, d, e,_ will each and all discharge into _l_ through the paths by which their original discharge took place. Similarly they will discharge into _m, n, o,_ and _p_; and these latter tracts will also each reinforce the other's action because, in the experience B, they have already vibrated in unison. The lines in Fig. 40 symbolize the summation of discharges into each of the components of B, and the consequent strength of the combination of influences by which B in its totality is awakened.
Hamilton first used the word 'redintegration' to designate all association. Such processes as we have just described might in an emphatic sense be termed redintegrations, for they would necessarily lead, if unobstructed, to the reinstatement in thought of the _entire_ content of large trains of past experience. From this complete redintegration there could be no escape save through the irruption of some new and strong present impression of the senses, or through the excessive tendency of some one of the elementary brain-tracts to discharge independently into an aberrant quarter of the brain. Such was the tendency of the word 'heir' in the verse from 'Locksley Hall,' which was our first example. How such tendencies are constituted we shall have soon to inquire with some care. Unless they are present, the panorama of the past, once opened, must unroll itself with fatal literality to the end, unless some outward sound, sight, or touch divert the current of thought. Let us call this process _impartial redintegration_. Whether it ever occurs in an absolutely complete form is doubtful. We all immediately recognize, however, that in some minds there is a much greater tendency than in others for the flow of thought to take this form. Those insufferably garrulous old women, those dry and fanciless beings who spare you no detail, however petty, of the facts they are recounting, and upon the thread of whose narrative all the irrelevant items cluster as pertinaciously as the essential ones, the slaves of literal fact, the stumblers over the smallest abrupt step in thought, are figures known to all of us. Comic literature has made her profit out of them. Juliet's nurse is a classical example. George Eliot's village characters and some of Dickens's minor personages supply excellent instances.
Perhaps as successful a rendering as any of this mental type is the character of Miss Bates in Miss Austen's 'Emma.' Hear how she redintegrates: "'But where could _you_ hear it?' cried Miss Bates. 'Where could you possibly hear it, Mr. Knightley? For it is not five minutes since I received Mrs. Cole's note--no, it cannot be more than five--or at least ten--for I had got my bonnet and spencer on, just ready to come out--I was only gone down to speak to Patty again about the pork--Jane was standing in the passage--were not you, Jane?--for my mother was so afraid that we had not any salting-pan large enough. So I said I would go down and see, and Jane said: "Shall I go down instead? for I think you have a little cold, and Patty has been washing the kitchen." "Oh, my dear," said I--well, and just then came the note. A Miss Hawkins--that's all I know--a Miss Hawkins, of Bath. But, Mr. Knightley, how could you possibly have heard it? for the very moment Mr. Cole told Mrs. Cole of it, she sat down and wrote to me. A Miss Hawkins--'" But in every one of us there are moments when this complete reproduction of all the items of a past experience occurs. What are those moments? They are moments of emotional recall of the past as something which once was, but is gone for ever--moments, the interest of which consists in the feeling that our self was once other than it now is. When this is the case, any detail, however minute, which will make the past picture more complete, will also have its effect in swelling that total contrast between _now_ and _then_ which forms the central interest of our contemplation.
Text from Project Gutenberg, public domain in the United States.