Having this thought in mind, _Comenius_, more than two and a half centuries ago, said, "It is certain that there is nothing in the understanding which has not been previously in the senses, and consequently to exercise the senses carefully in discriminating the differences of natural objects is to lay the foundation of all wisdom, all eloquence, and of all good and prudent action. The right instruction of youth does not consist in cramming them with a ma.s.s of words, phrases, sentences, and opinions collected from authors. In this way the youth are taught, like Aesop's crow in the fable, to adorn themselves with strange feathers. Why should we not, instead of dead books, open the living book of nature? Not the shadows of things, but the things themselves, which make an impression upon the senses and imagination, are to be brought before the youth."

There has always been a strong tendency in the schools to teach _words, definitions, and rules_ without a sufficient knowledge of the objects and experiences of life that put meaning into these abstractions. The result is that all the prominent educational reformers have pointedly condemned the practice of learning words, names, etc., without a knowledge of the things signified. The difference is like that between learning the names of a list of persons at a reception, and being present to enter into acquaintance and conversation with the guests.

The oft-quoted dictum of Kant is a laconic summary of this argument.

"General notions (concepts) without sense-percepts are empty." The general definition of composite flowers means little or nothing to a child; but after a familiar acquaintance with the sunflower, dandelion, thistle, etc., such a general statement has a clear meaning. Concepts without the content derived from objects are like a frame without a picture, or a cistern without water. The table is spread and the dishes placed, but no refreshments are supplied.

Having completed the discussion of _intuition_, including object lessons, that is, the preparatory step to the inductive process, we reach the second, _reflection_ and _survey_. We are seeking for a general term that covers the several steps in the latter part of the inductive process. It includes comparison, cla.s.sification, and abstraction. It may be discussed from the standpoint of "a.s.sociation of ideas," and contributes directly to concentration.

We have in mind, chiefly, that thoughtful habit which is not satisfied with simply acquiring a new fact or set of ideas, but is impelled to trace them out along their various connections. We have to do now not with the acquisition but with the _elaboration_ and _a.s.similation_ of knowledge. The _acquisition_ of knowledge in the ordinary sense is one thing; its _elaboration_ in a full sense sets up a standard of progress which will put life into all school work and reach far beyond it, and in fact is limited only by the individual capacity for thought. In school, in reading and study, we have been largely engaged in acquiring knowledge on the principle that "knowledge is power." But no practical man needs to be told that much so-called school knowledge is not power.

Facts which have been simply stored in the memory are often of little ready use. It is like wheat in the bin, which must first pa.s.s through the mill and change its entire form before it will perform its function. Facts, in order to become the personal property of the owner, must be worked over, sifted, sorted, cla.s.sified, and connected.

The process of elaborating and a.s.similating knowledge is so important that it requires more time and pains than the first labor of acquisition. Philosophers will admit this at once, but it is hard for us to break loose from the traditions of the schoolmasters. The mind is not in all respects like a _lumber-yard_. It is, to be sure, a place for storing up knowledge, just as the yard is a deposit for lumber. But there the a.n.a.logy ceases and the mind begins to resemble more the contractor and builder. There is planing, sawing, and hammering; the materials collected are prepared, fitted, and mortised together, and a building fit for use begins to rise. Knowledge also is for use, and not primarily for storage. That simple acquisition and quant.i.ty of knowledge are not enough is ill.u.s.trated by the a.n.a.logy of an army. Numbers do not make an army, but a rabble. A general first enlists raw recruits, drills and trains them through a long period, and finally combines them into an effective army. Many of our ideas when first received are like disorderly raw recruits. They need to be disciplined into proper action and to ready obedience.

In connection with a.s.similation the a.n.a.logy between the _stomach_ and the mind is of still greater interest. The food received into the stomach is taken up by the organs of digestion, a.s.similated and converted into blood. The process, however, takes its course without our conscious effort or co-operation. Knowledge likewise enters the mind, but how far will a.s.similation go on without conscious effort? If kept in a healthy state the organs of digestion are self active. Not so the mind. Ideas entering the mind are not so easily a.s.similated as the food materials that enter the stomach. A cow chews her cud once, but the ideas that enter our minds may be drawn from their receptacle in the memory and worked over again and again. Ideas have to be put side by side, separated, grouped, and arranged into connected series.

There is, no doubt, some tendency in the mind toward involuntary a.s.similation, but it greatly needs culture and training. Many people never reach the _thinking_ stage, never learn to survey and reflect.

The tendency of the mind to work over and digest knowledge should receive ample culture in the schools. There is a mental inertia produced by pure memory exercise that is unfavorable to reflection. It requires an extra exertion to arrange and organize facts even after they are acquired. But when the habit of reflection has been inaugurated it adds much interest and value to all mental acquisitions.

There are also well-established principles which guide the mind in elaborating its facts. The _laws of the a.s.sociation_ of ideas indicate clearly the natural trend of mental elaboration. The a.s.sociation of things because of contiguity in time and place is the simplest mode.

The cla.s.sification of objects or activities on the basis of resemblance, is the second form and that upon which the inductive process is princ.i.p.ally founded. In the third case objects and series are easily retained in memory when the relation of cause and effect is perceived between them. These natural highways of a.s.sociation, especially the second and third, should be frequently traveled in linking the facts of school study with each other. Indeed the outcome of a rational survey of an object or fact in its different relations is an a.s.sociation of ideas which is one of the best results of study.

Such connections of resemblance and difference or of cause and effect are abundant and interesting in the natural sciences and physical geography, also in history and languages.

The Herbartians draw an important distinction between _psychical_ and _logical_ concepts or general notions. The _psychical_ concept is worked out naturally by a child or an adult as a result of the chance experiences of life. It is usually a work of accident; is incomplete, faulty, and often misleading. The _logical_ concept, on the other hand, is scientifically correct and complete. It includes all the common characteristics of the group and excludes all that are not essential. It is a product of accurate and mature thinking. We all possess an abundance of psychical concepts drawn from the miscellaneous experiences of life. It is a large share of the school work, as we have seen, to develop logical concepts out of these immature and faulty psychical concepts. A child is disposed to call tadpoles fishes; and later porpoises and whales are faultily cla.s.sed with the fishes in the same way. Nearly all our psychical concepts are subject to such loose and faulty judgments. Even where one is accurate in his observations, the conclusions naturally drawn are often wrong. For example, a child that has seen none but red squirrels would naturally think all squirrels red, and include the quality red in his general notion. Most of our empirically derived general notions are spotted with such defects. What relation have these facts to induction? We claim that general notions should be experimentally formed; that is, by a gradual collection of concrete or ill.u.s.trative materials, and that the logical concepts are the final outcome of comparison and reasoning toward conclusions. In other words, we must begin with psychical concepts with all their faults; we must make mistakes and correct them as our experience enlarges, and gradually work out of psychical into logical methods and results. Our text-books usually give us the logical concept first, the rule, definition, principle, in its most complete and accurate statement. This does violence to the child's natural mental movement.

The final stage of induction is the _formulation_ of the general truths, the concepts, principles, and laws which const.i.tute the science of any branch of knowledge. These truths should be well formulated in clear and expressive language and mastered in this form. Moreover, the results reached, when reduced to the strict scientific form, are the same in the inductive methods as in the deductive or common text-book method. Not that the effect on the mind of the learner is the same but the body of truth is unaltered. The general truths of every subject can be easily found well arranged in text-books. But we are more anxious to know how the youth may best approach and appreciate these truths than simply to see them stored in the mind in a well-cla.s.sified form.

A rich man in leaving a fortune to his son would more than double the value of the inheritance if he could teach him properly to _appreciate_ wealth and form in him the disposition and ability to use it wisely.

In the same way the best part of knowledge is not simply its possession, but an appreciation of its value. The method of reaching scientific knowledge through the inductive process, that is by the collection and comparison of data with a view to positive insight, will give greater meaning to the results. Interest is awakened and self-activity exercised at every step in the progress toward general truths. By the reflective habit these truths will be seen in their origin and causal connection, and the line of similarity, contrast, causal relation, a.n.a.logy and coincidence will be thoughtfully traced.

Possibly the progress toward formulated knowledge will be less rapid by induction, but it will be real progress with no backward steps. It may well be doubted whether, with average minds, real scientific knowledge is attainable except by a strong admixture of inductive processes.

Perfection in the form and structure of our concepts is not to be attained by children nor by adults, but the ideal of scientific accuracy in general notions is to be kept constantly in view and approximated to the extent of our ability.

After all, _deduction_ performs a much more important part in the work of building up concepts than the previous discussion would indicate.

As fast as psychical concepts are formed we clamber upon them and try to get a better view of the field around us. Like captured guns, we turn them at once upon the enemy and make them perform service in new fields of conquest. If a new case or object appears we judge of it in the light of our acquired concepts, no matter whether they are complete and accurate or not. This is deduction. We are glad to gain any vantage ground in judging the objects and phenomena constantly presenting themselves. In fact, it is inevitable that inductive and deductive processes will be constantly dovetailed into each other. The faulty concepts arrived at are brought persistently into contact with new individual cases. They are thus corrected, enlarged, and more accurately grasped. This is the series of mental stepping-stones that leads up gradually to logical concepts. The inductive process is the fundamental one and deduction comes in at every step to brace it up.

This is only another ill.u.s.tration that mental processes are intimately interwoven, and, except in thought, not to be separated. In the discussion of apperception in the following chapter we shall see that, in the process of gaining knowledge, our acquired ideas and concepts play a most important role. They are really the chief a.s.similating agencies. But in spite of all this we shall scarcely be led again to the standpoint that logical or scientific concepts should be the starting point in the study of any subject.

[1] Intuition is popularly used in a sense different from the above.

We are in need of a word which has the same meaning as the German word, _Anschauung_, for which there is no popular equivalent in English.

Intuition, as defined by Webster, is nearly the same: "direct apprehension, or cognition; immediate knowledge, as in perception or consciousness."

For a discussion of this term, see Quick's Educational Reformers, p.

361, Appleton's edition.

CHAPTER VI.

APPERCEPTION.

We have now to deal with a principle of pedagogy upon which all the leading ideas thus far discussed largely depend for their realization.

Interest, concentration, and induction set up requirements relative to the matter, spirit and method of school studies. Apperception is a practical principle, obedience to which will contribute daily and hourly to making real in school exercises the ideas of interest, concentration and induction.

We observe in pa.s.sing that the important principles already discussed stand in close mutual relation and dependence. Interest aids concentration by bringing all kinds of knowledge into close touch with the feelings. Interest puts incentives into every kind of information so as to arouse the will, which, in turn, unifies and controls the mental actions. But concentration has a reflex influence upon interest, because unity and conscious mastery give added pleasure to knowledge. The culture epochs are expected to contribute powerfully to both concentration and interest; to the former by supplying a series of rallying-points for educative effort, to the latter by furnishing matter suited to interest children. Induction is a natural method of acquiring and unifying knowledge in an interesting way. Apperception, in turn, is a principle of mental action which puts life and interest into inductive and concentrating processes. Every hour of school labor ill.u.s.trates the value of apperception and teachers should find in it a constant antidote to faulty methods.

Apperception may be roughly defined at first as the process of _acquiring new ideas by the aid of old ideas_ already in the mind. It makes the acquisition of new knowledge easier and quicker. Not that there is any easy road to learning, but there is a natural process which greatly accelerates the progress of acquisition, just as it is better to follow a highway over a rough country than to betake one's self to the stumps and brush. For example, if one is familiar with peaches, apricots will be quickly understood as a kindred kind of fruit, even though a little strange. A person who is familiar with electrical machinery will easily interpret the meaning and purpose of every part of a new electrical plant. One may _perceive_ a new object without understanding it, but to _apperceive_ it is to interpret its meaning by the aid of similar familiar notions.

If one examines a _typewriter_ for the first time, it will take some pains and effort to understand its construction and use; but after examining a Remington, another kind will be more easily understood, because the principle of the first interprets that of the second.

Suppose the _Steppes of Russia_ are mentioned for the first time to a cla.s.s. The word has little or no meaning or perhaps suggests erroneously a succession of stairs. But we remark that the steppes are like the prairies and plains to the west of the Mississippi river, covered with gra.s.s and fed on by herds. By awakening a familiar notion already in the mind and bringing it distinctly to the front, the new thing is easily understood. Again, a boy goes to town and sees a _banana_ for the first time, and asks, "What is that? I never saw anything like that." He thinks he has no cla.s.s of things to which it belongs, no place to put it. His father answers that it is to eat like an orange or a pear, and its significance is at once plain by the reference to something familiar.

Again, two men, the one a _machinist_ and the other an observer unskilled in machines, visit the machinery hall of an exposition. The machinist observes a new invention and finds in it a new application of an old principle. As he pa.s.ses along from one machine to another he is much interested in noting new devices and novel appliances and at the end of an hour he leaves the hall with a mind enriched. The other observer sees the same machines and their parts, but does not detect the principle of their construction. His previous knowledge of machines is not sufficient to give him the clue to their explanation.

After an hour of uninterested observation he leaves the hall with a confused notion of shafts, wheels, cogs, bands, etc., but with no greater insight into the principles of machinery. Why has one man learned so much and the other nothing? Because the machinist's previous experience served as an interpreter and explained these new contrivances, while the other had no sufficient previous knowledge and so acquired nothing new. "To him that hath shall be given."

In the act of apperception the old ideas dwelling in the mind are not to be regarded as dead treasures stored away and only occasionally drawn out and used by a purposed effort of the memory, but they are _living forces_ which have the active power of seizing and appropriating new ideas. Lazarus says they stand "like well-armed men in the inner stronghold of the mind ready to sally forth and overcome or make serviceable whatever shows itself at the portals of sense." It is then through the active aid of familiar ideas that new things find an introduction to soul life. If old friends go out to meet the strangers and welcome them, there will be an easy entrance and a quick adoption into the new home.

But frequently these old friends who stand in the background of our thoughts must be _awakened_ and called to the front. They must stand as it were on tiptoe ready to welcome the stranger. For if they lie asleep in the penetralia of the home the new comers may approach and pa.s.s by for lack of a welcome. It is often necessary, therefore, for the teacher to revive old impressions, to call up previously acquired knowledge and to put it in readiness to receive and welcome the new.

The success with which this is done is often the difference between good and poor teaching.

We might suppose that when two persons look at the same object they would get the _same impression_, but this is not true at all. Where one person faints with fright or emotion another sees nothing to be disturbed at. Two travelers come in sight of an old homestead. To one it is an object of absorbing interest as the home of his childhood; to the other it is much like any other old farm house. What is the cause of this difference? Not the house. It is the same in both cases. It is remarkable how much color is given to every idea that enters into the mind by the ideas already there. Some visitors at the World's Fair can tell almost at a glance to what states many of the buildings belong; other visitors must study this out on the maps and notices.

One who is familiar with the history, architecture, and products of the different states is able to cla.s.sify many of the buildings with ease.

His previous knowledge of these states interprets their buildings. Mt.

Vernon naturally belongs to Virginia, Independence Hall to Pennsylvania, John Hanc.o.c.k's house to Ma.s.sachusetts. In a still more striking manner, a knowledge of foreign countries enables the observer to cla.s.sify such buildings as the French, the German, the Swedish, the j.a.panese, etc. Again, in viewing any exhibit our enjoyment and appreciation depend almost entirely upon our previous knowledge, not upon our eye-sight or our physical endurance. Many objects of the greatest value we pa.s.s by with an indifferent glance because our previous knowledge is not sufficient to give us their meaning.

If a dry goods merchant, a horse jockey, and an architect pa.s.s down a city street together, what will each observe? The merchant notices all the dry goods stores, their displays, and their favorable or unfavorable location. The jockey sees every horse and equipage; he forms a quiet but quick judgment upon every pa.s.sing animal. The architect sees the buildings and style of construction. If in the evening each is called upon to give his observations for the day, the jockey talks of horses and describes some of the best specimens in detail; the merchant speaks of store-fronts and merchandise; the architect is full of elevations of striking or curious buildings. The architect and merchant remember nothing, perhaps, about the horses; the jockey nothing of stores or buildings. Three people may occupy the same pew in a church; the one can tell you all about the music, the second the good points in the sermon, and the third the style and becomingness of the bonnets and dresses. Each one sees what he has in his own mind. A teacher describes Yosemite Valley to a geography cla.s.s. Some of the children construct a mental picture of a gorge with steep mountain sides, but no two pictures are alike; some have mental pictures that resemble nothing in heaven above or earth below; some have constructed----nothing at all! only the echo of a few spoken words. If the teacher, at the close of her description, could have the mental state of each child photographed on the blackboard of her schoolroom she would be in mental distress. In presenting such topics to children, much depends upon the previous content of their minds, upon the colors out of which they paint the pictures.

We are now prepared for a more accurate _definition_ of apperception.

"The transformation of a newer (weaker) concept by means of an older one surpa.s.sing the former in power and inner organization bears the name of apperception, in contrast to the unaltered reception of the same perception." (Lindner's Psychol. p. 124, trans. by De Garmo.) Lindner remarks further, "Apperception is the reaction of the old against the new--in it is revealed the preponderance which the older, firmer, and more self-contained concept groups have in contrast to the concepts which have just entered consciousness." Again, "It is _a kind of process of condensation of thought_ and brings into the mental life a certain stability and firmness, in that it subordinates new to older impressions, puts everything in its right place and in its right relation to the whole, and in this way works at that organic formation of our consciousness which we call _culture_." (Lindner p. 126.) "Apperception may be defined as that interaction between two similar ideas or thought-complexes in the course of which the weaker, unorganized, isolated idea or thought-complex is incorporated into the richer, better digested, and more firmly compacted one." (Lange, Apperception, p. 13.)

Oftentimes, therefore, older ideas or thought ma.s.ses, being clear, strong, and well-digested receive a new impression to modify and appropriate it. This is especially true where opinions have been carefully formed after thought and deliberation. A well-trained political economist, for example, when approaching a new theory or presentation of it by a George or Bellamy, meets it with all the resources of a well-stored, thoughtful mind; and admits it, if at all, in a modified form to his system of thought. Sometimes, however, a new theory, which strikes the mind with great clearness and vigor, is able to make a powerful a.s.sault upon previous opinions, and perhaps modify or overturn them. This is the more apt to be the case if one's previous ideas have been weak and undecided. In the interaction between the old and new the latter then become the apperceiving forces.

Upon the untrained or poorly-equipped mind a strong argument has a more decisive effect than it may justly deserve. As we noticed above, new ideas, especially those coming directly through the senses, are often more vivid and attractive than similar old ones. For this reason they usually occupy greater attention and prominence at first than later, when the old ideas have begun to revive and rea.s.sert themselves. Old ideas usually have the advantage over the new in being better organized, more closely connected in series and groups; and having been often repeated, they acquire a certain permanent ascendency in the thoughts. In this interaction between similar notions, old and new, the differences at first arrest attention, then gradually sink into the background, while the stronger points of resemblance begin to monopolize the thought and bind the notions into a unity.

The use of familiar notions in acquiring an insight into new things is a _natural tendency_ or drift of the mind. As soon as we see something new and desire to understand it, at once we involuntarily begin to ransack our old stock of ideas to discover anything in our previous experience which corresponds to this or is like it. For whatever is like it or has an a.n.a.logy to it, or serves the same uses, will explain this new thing, though the two objects be in other points essentially different. We are, in short, constantly falling back upon our old experiences and cla.s.sifications for the explanation of new objects that appear to us.

So far is this true that the _most ordinary things_ can only be explained in the light of experience. When John Smith wrote a note to his companions at Jamestown, and thus communicated his desires to them, it was unintelligible to the Indians. They had no knowledge of writing and looked on the marks as magical. When _Columbus' ships_ first appeared on the cost of the new world, the natives looked upon them as great birds. They had never seen large sailing vessels. To vary the ill.u.s.tration, the _art of reading_, so easy to a student, is the acc.u.mulated result of a long collection of knowledge and experience.

There is an unconscious employment of apperception in the practical affairs of life that is of interest. We often see a person at a distance and by some slight characteristic of motion, form, or dress, recognize him at once. From this slight trace we picture to ourselves the person in full and say we saw him in the street. Sitting in my room at evening I hear the regular pa.s.senger train come in. The noise alone suggests the engine, cars, conductor, pa.s.sengers, and all the train complete. As a matter of fact I saw nothing at all but have before my mind the whole picture. On Sunday morning I see some one enter a familiar church door, and going on my way the whole picture of church, congregation, pastor, music and sermon come distinctly to my mind. Only a pa.s.sing glance at one person entering suggests the whole scene. In looking at a varied landscape we see many things which the sensuous eye alone would not detect, distances, perspective and relative size, position and nature of objects. This apperceptive power is of vast importance in practical life as it leads to quick judgment and action, when personal examinations into details would be impossible.

In apperception we never pa.s.s from the known to things which are _entirely new_. Absolutely new knowledge is gained by perception or intuition. When an older person meets with something totally new, he either does not notice it or it staggers him. Apperception does not take place. In many cases we are disturbed or frightened, as children, by some new or sudden noise or object. But most so-called new things bear sufficient resemblance to things seen before to admit of explanation. Strange as the sights of a Chinese city might appear, we should still know that we were in a city. In most "new" objects of observation or study, the familiar parts greatly preponderate over the unfamiliar. In a new reading lesson, for example, most of the words and ideas are well known, only an occasional word requires explanation and that by using familiar ill.u.s.trations. The flood of our familiar and oft-repeated ideas sweeps on like a great river, receiving here and there from either side a tributary stream, that is swallowed up in its waters without perceptible increase.

So strong is the apperceiving force of familiar notions that they drag far-distant scenes in geography and history into the home neighborhood and locate them there. The _imagination_ works in conjunction with the apperceiving faculty and constructs real pictures. Children are otherwise inclined to subst.i.tute one thing for another by imagination.

With boys and girls, geographical objects about home are often converted by fancy into representatives of distant places. It is related of _Byron_ that while reading in childhood the story of the Trojan war, he localized all the places in the region of his home. An old hill and castle looking toward the plain and the sea were his Troy.

The stream flowing through the plain was the Simois. The places of famous conflicts between the Trojans and Greeks were located. So vivid were the pictures which these home scenes gave to the child, that years later in visiting Asia Minor and the sight of the real Troy, he was not so deeply impressed as in his boyhood. A _German professor_ relates that he and his companions, while reading the Indian stories of Cooper, located the important scenes in the hills and valleys about Eisenach in the Thuringian mountains. Many other ill.u.s.trations of the same imaginative tendency to subst.i.tute home objects for foreign ones are given. But whether or not this experience is true of us all, it is certain that we can form no idea of foreign places and events except as we _construct_ the pictures out of the _fragments_ of things that we have known. What we have seen of rivers, lands, and cities must form the materials for picturing to ourselves distant places.

Since the old ideas have so much to do with the proper reception of the new, let us examine more closely the _interaction_ of the two. If a _new idea_ drops into the mind, like a stone upon the surface of the water, it produces a commotion. It acts as a stimulus or wakener to the old ideas sleeping beneath the surface. It draws them up above the surface-level; that is, into consciousness. But what ideas are thus disturbed? There are thousands of these latent ideas, embryonic thoughts, beneath the surface. Those which possess sufficient kinship to this new-comer to hear his call, respond. For in the mind "birds of a feather flock together." Ideas and thoughts which resemble the new one answer, the others sleep on undisturbed, except a few who are so intimately a.s.sociated with these kinsmen as to be disturbed when they are disturbed. Or, to state it differently, certain thought-groups or complexes, which contain elements kindred to the new notion, are agitated and raised into conscious thought. They seem to respond to their names. The new idea may continue for some time to stimulate and agitate. There appears to be a sort of telegraphic inquiry through the regions of the mind to find out where the kindred dwell. The distant relatives and strangers (the unrelated or unserviceable ideas) soon discover that they have responded to the wrong call and drop back to sleep again. But the real kindred wake up more and more. They come forward to inspect the new-comer and to examine his credentials. Soon he finds that he is surrounded by inquisitive friends and relatives.

They threaten even to take possession of him. Up to this point the new idea has taken the lead, he has been the aggressor. But now is the time for the awakened kindred ideas to a.s.sume control and lead the stranger captive, to bring him in among themselves and give him his appropriate place and importance. The _old body of ideas_, when once set in motion, is more powerful than any single-handed stranger who happens to fall into their company. The outcome is that the stranger, who at first seemed to be producing such a sensation, now discovers that strong arms are about him and he is carried captive by vigorous friends. New ideas when first entering the mind are very strong, and, if they come through the senses, are especially rich in the color and vigor of real life. They therefore absorb the attention at first and seem to monopolize the mental energies; but the older thought ma.s.ses, when fully aroused, are better organized, more firmly rooted in habit, and possess much wider connections. They are almost certain, therefore, to apperceive the new idea; that is, to conquer and subdue it, to make it tributary to their power.

Let us examine more closely the _effect_ of the process of apperception upon the new and old ideas that are brought in contact. First, observe the effect upon the _new_: Many an idea which is not strong enough in itself to make a lasting impression, upon the mind would quickly fade out and be forgotten were it not that in this process the old ideas throw it into a clear light, give it more meaning, a.s.sociate it closely with themselves, and thus save it. Two persons look at the sword of Washington; one examines it with deep interest, the other scarcely gives it a second glance. The one remembers it for life, the other forgets it in an hour. The sense perception was the same in both persons at first, but the reception given to the idea by one converts it into a lasting treasure. A little lamp-black, rolled up between finger and thumb, suggested to Edison his carbon points for the electric light. A piece of lamp-black would produce no such effect in most peoples minds. The difference is in the reception accorded to an idea. The meaning and importance of an idea or event depend upon the interpretation put upon it by our previous experience. "Many a weak, obscure, and fleeting perception would pa.s.s almost unnoticed into obscurity, did not the additional activity of apperception hold it fast in consciousness. This sharpens the senses, _i.e._, it gives to the organs of sense a greater degree of energy, so that the watching eye now sees, and the listening ear now hears, that which ordinarily would pa.s.s unnoticed. The events of apperception give to the senses a peculiar keenness, which underlies the skill of the money-changer in detecting a counterfeit among a thousand bank-notes, notwithstanding its deceptive similarity; of the jeweler who marks the slightest, apparently imperceptible, flaw in an ornament; of the physicist who perceives distinctly the overtones of a vibrating string. According to this we see and hear not only with the eye and ear, but quite as much with the help of our present knowledge, with the apperceiving content of the mind." (Apperception, Lange, De Garmo, p. 21.)

Some even intelligent and sensible people can walk through Westminster Abbey and see nothing but a curious old church with a few graves and monuments. To a person well-versed in English history and literature it is a shrine of poets, a temple of heroes, the common resting-place of statesmen and kings.

Secondly, what is the _effect on the old ideas_? Every idea that newly enters the mind produces changes in the older groups and series of thought. Any one new idea may cause but slight changes, but the constant influx of new experiences works steadily at a modification and rearrangement of our previous stores of thought. Faulty and incomplete groups and concepts are corrected or enlarged; that is, changed from psychical into logical notions. Children are surprised to find little flowers on the oaks, maples, walnuts, and other large forest trees. On account of the small size of the blossoms, heretofore unnoticed, they had not thought of the great trees as belonging to the flowering plants. Their notion of flowering plants is, therefore, greatly enlarged by a few new observations. The bats flying about in the twilight have been regarded as birds; but a closer inspection shows that they belong to another cla.s.s, and the notion bird must be limited.