Many persons confuse the idea of Sensation and Perception, but there is a clear distinction between them. Sensations arise from nerve action--from the stimulation of nerve substance--which gives rise to a peculiar effect upon the brain, which results in an elementary form of consciousness. An authority says: "Sensation is the peculiar property of the nervous system in a state of activity, by which impressions are conveyed to the brain or sensorium. When an impression is made upon any portion of the bodily surface by contact, heat, electricity, light, or any other agent, the mind is rendered conscious of this by sensation.

In the process there are three stages--reception of the impression at the end of the sensory nerve, the conduction of it along the nerve trunk to the sensorium, and _the change it excites in the sensorium itself, through which is produced sensation_."

Just why and how this nerve action is translated into consciousness of an elementary kind, science is unable to explain. Our knowledge is based in a great part, or entirely, upon impressions which have been received over the channel of the senses--sensations of sight, hearing, tasting, smelling and touch. Many authorities hold that all of the five senses are modifications of the sense of touch, or feeling; as for instance, the impression upon the organs of sight is really in the nature of a delicate touch or feeling of the light-waves as they come in contact with the nerves of vision, etc. But, although sensations give us the raw materials of thought, so to speak, they are not _knowledge_ in themselves. Knowledge arises from the operation of Perception upon this raw material of Sensation.

But yet, Sensation plays a most active part in the presentation of the raw material for the Perceptive faculties, and must not be regarded as merely a physiological process. It may be said to be the connecting link between the physical and the mental activities. As Ziehen says: "It follows that the const.i.tution of the nervous system is an essential factor in determining the quality of sensation. This fact reveals the obvious error of former centuries, first refuted by Locke, though still shared by naive thought today, that the objects about us themselves are colored, warm, cold, etc. As external to our consciousness, we can only a.s.sume matter, vibrating with molecular motion and permeated by vibrating particles of ether. The nervous apparatus selects only certain motions of matter or of ether, which they transform into that form of nerve excitation with which they are familiar. It is only this nerve excitation that we perceive as red, warm or hard."

Pa.s.sing from Sensation to Perception, we see that the latter interprets the reports of the former. Perception translates into consciousness the impressions of Sensation. Perception, acting through one or more of the mental faculties, gives us _our first bit of real knowledge_. Sensation may give us the impression of a small moving thing--Perception translates this into the thought of _a cat_. Sensation is a mere _feeling_--Perception is the _thought_ arising from that feeling. A Percept is the product of Perception, or in other words, our _idea_ gained through Perception. The majority of our percepts are complex, being built up from a number of minor percepts; as for instance, our percept of _a peach_ is built up from our minor percepts of the form, shape, color, weight, degree of hardness, smell, taste, etc., of the peach, each sense employed giving minor percepts, the whole being combined in the conscious as the whole percept of that particular peach.

Brooks says: "All knowledge does not come directly from perception through the senses, however. We have a knowledge of external objects, and we have a knowledge that transcends this knowledge of external objects. Perception is the _immediate_ source of the first kind of knowledge, and the _indirect_ source of the second kind of knowledge.

This distinction is often expressed by the terms _cause_ and _occasion_. Thus perception is said to be the _cause_ of our knowledge of objects, since it is the immediate source of such knowledge.

Perception is also said to be the _occasion_ of the ideas and truths of intuition; for, though in a sense necessary to these ideas, it is not the source of them. Perception also furnishes the understanding with materials out of which it derives ideas and truths beyond the field of sense. As thus attaining a knowledge of external objects, affording material for the operations of the understanding, and furnishing the occasion for the activity of the intuitive power, _perception may be said to lie at the basis of all knowledge_."

Perception is of course manifest in all persons. But it varies greatly in degree and power. Moreover, it may be developed and cultivated to a great degree. As Perception is an interpretation of the impression of the senses, we often confuse the cultivation of Perception with the development of the senses themselves. Two persons of equally perfect sense of sight may vary greatly in their degree of Perception of sight impressions. One may be a most careless observer, while the other may be a very close observer and able to distinguish many points of interest and importance in the object viewed which are not apparent to the first observer. Cultivation of Perception is cultivation of the _mental background of the senses_, rather than of the sense organs themselves.

The Perception accompanying each sense may be developed and cultivated separately from that accompanying the others.

The majority of persons are very careless observers. They will _see_ things without _perceiving_ the qualities, properties, characteristics, or parts which together make up those things. Two persons, possessed of equal degrees of eyesight, will walk through a forest. Both of them will _see_ trees. To one of them there will be but trees perceived; while to the other there will be a perception of the different species of trees, with their varying bark, leaves, shape, etc. One perceives simply a "pile of stone," which to the perception of another will be recognized as granite, marble, etc. Brooks says: "Very few persons can tell the difference between the number of legs of a fly and of a spider; and I have known farmers' boys and girls who could not tell whether the ears of a cow are in front of her horns, above her horns, below her horns, or behind her horns." Halleck says of a test in a schoolroom: "Fifteen pupils were sure that they had seen cats climb trees and descend them.

There was a unanimity of opinion that the cats went up head first. When asked whether the cats came down head or tail first, the majority were sure that the cats descended as they were never known to do. Anyone who had ever noticed the shape of the claws of any beast of prey could have answered that question without seeing an actual descent. Farmers' boys, who have often seen cows and horses lie down and rise, are seldom sure whether the animals rise with their fore or hind feet first, or whether the habit of the horse agrees with that of the cow in this respect."

Brooks well says: "Modern education tends to the neglect of the culture of the perceptive powers. In ancient times people studied nature much more than at present. Being without books, they were compelled to depend upon their eyes and ears for knowledge; and this made their senses active, searching and exact. At the present day, we study books for a knowledge of external things; and we study them too much or too exclusively, and thus neglect the cultivation of the senses. We get our knowledge of the material world second-hand, instead of fresh from the open pages of the book of nature. Is it not a great mistake to spend so much time in school and yet not know the difference between the leaf of a beech and of an oak; or not be able to distinguish between specimens of marble, quartz, and granite? The neglect of the culture of the perceptive powers is shown by the scholars of the present time. Very few educated men are good observers; indeed, the most of them are sadly deficient in this respect.... They were taught to think and remember; but were not taught to use their eyes and ears. In modern education, books are used too much like spectacles, and the result is the blunting of the natural powers of perception."

The first principle in the Cultivation of Perception is the correct use of the Attention. The intelligent control of voluntary attention is a prerequisite to clear and distinct perception. We have called your attention to this matter in the preceding chapter. Halleck says: "A body may be imaged on the retina without insuring perception. There must be an effort to concentrate the attention upon the many things which the world presents to our senses.... Perception, to achieve satisfactory results, must summon the will to its aid to concentrate the attention.

Only the smallest part of what falls upon our senses at any time is actually perceived."

The sense of sight is perhaps the one of the greatest importance to us, and accordingly the cultivation of Perception with regard to impressions received through the eye is the most important for the ordinary individual. As Kay says: "To see clearly is a valuable aid even to thinking clearly. In all our mental operations we owe much to sight. To recollect, to think, to imagine, is to see internally,--to call up more or less visual images of things before the mind. In order to understand a thing it is generally necessary to see it, and what a man has not seen he cannot properly realize or image distinctly to his mind.... It is by the habitual direction of our attention to the effects produced upon our consciousness by the impressions made upon the eye and transmitted to the sensorium that our sight, like our other senses, is trained."

Bain says: "Cohering trains and aggregates of the sensations of sight make more than any other thing, perhaps more than all other things put together, the material of thought, memory and imagination." Vinet says: "The child, and perhaps the man as well, only knows well what is shown him, and the image of things is the true medium between their abstract idea and his personal experience." This being the case, advice concerning the Cultivation of Perception must needs be directed mainly to the cultivation of the perception of sight-impressions.

Brooks says: "We should acquire the habit of observing with attention.

Many persons look at objects with a careless, inattentive eye. We should guard against the habit of careless looking. We should fix the mind upon the object before us; we should concentrate the attention upon that upon which we are looking. Attention, in respect to Perception, has been compared to a burning gla.s.s; hold the sun-gla.s.s between the sun and a board and the concentrated rays will burn a hole through the latter. So attention concentrates the rays of perceptive power and enables the mind to penetrate below the surface of things."

The best authorities agree in the idea that the Perception may be best cultivated by acquiring the habit of examining things in detail. And, that this examination in detail is best manifested by examining the parts going to make up a complex thing, separately, rather than examining the thing as a whole. Halleck says regarding this point: "To look at things intelligently is the most difficult of all arts. The first rule for the cultivation of accurate perception is: Do not try to perceive the whole of a complex object at once. Take the human face for example. A man holding an important position to which he had been elected offended many people because he could not remember faces, and hence failed to recognize individuals the second time he met them. His trouble was in looking at the countenance as a whole. When he changed his method of observation, and noticed carefully the nose, mouth, eyes, chin and color of hair, he at once began to find recognition easier. He was no longer in danger of mistaking A for B, since he remembered that the shape of B's nose was different, or the color of his hair at least three shades lighter. This example shows that another rule can be formulated: Pay careful attention to details.... To see an object merely as an undiscriminated ma.s.s of something in a certain place is to do no more than a donkey accomplishes as he trots along."

Brooks says regarding the same point: "To train the powers of observation we should practice observing minutely. We should a.n.a.lyze the objects which we look at into their parts, and notice these parts.

Objects present themselves to us as wholes; our definite knowledge of them is gained by a.n.a.lysis, by separating them into the elements which compose them. We should therefore give attention to the details of whatever we are considering; and thus cultivate the habit of observing with minuteness.... It is related of a teacher that if, when hearing a cla.s.s, some one rapped at the door, he would look up as the visitor entered and from a single glance could tell his appearance and dress, the kind of hat he wore, kind of necktie, collar, vest, coat, shoes, etc. The skillful banker, also, in counting money with wondrous rapidity, will detect and throw from his pile of bills the counterfeits which, to the ordinary eye, seem to be without spot or blemish."

One of the best methods of developing and cultivating the faculty of Perception is to take up some study in which the perceptive faculties _must be_ employed. Botany, physics, geology, natural history give splendid exercise in Perception, providing the student engages in actual experimental work, and actual observation, instead of confining himself to the textbooks. A careful scientific study and examination of _any kind of objects_, in a manner calculated to bring out the various points of resemblance and difference, will do most to develop the Perception.

Training of this kind will develop these powers to a high degree, in the case of small children.

Drawing is also a great help to the development of Perception. In order to draw a thing correctly we must of necessity examine it in detail; otherwise we will not be able to draw it correctly. In fact, many authorities use the test of drawing to prove the degree of attention and Perception that the student has bestowed upon an object which he has been studying. Others place an object before the pupil for a few minutes, and then withdraw it, the pupil then being required to draw the object roughly but with attention to its leading peculiarities and features. Then the object is again placed before the pupil for study, and he is then again required to draw from memory the additional details he has noticed in it. This process is repeated over and over again, until the pupil has proved that he has _observed_ every possible detail of interest in the object. This exercise has resulted in the cultivation of a high degree of perception in many students, and its simplicity should not detract from its importance. Any person may practice this exercise by himself; or, better still, two or more students may combine and endeavor to excel each other in friendly rivalry, each endeavoring to discover the greatest number of details in the object considered. So rapidly do students improve under this exercise, that a daily record will show a steady advance. Simple exercises in drawing are found in the reproduction, from memory, of geography maps, leaves of trees, etc.

Similar exercises may be found in the practice of taking a hasty look at a person, animal or building, and then endeavoring to reproduce in writing the particular points about the person or thing observed. This exercise will reveal rapid progress if persisted in. Or, it may be varied by endeavoring to write out the contents of a room through which one has walked.

The majority of our readers remember the familiar story of Houdin, who so cultivated the faculty of Perception that he was able to pa.s.s by a shop-window and afterward state in detail every object in the window. He acquired this power by gradual development, beginning with the observation of a single article in the window, then two, then three and so on. Others have followed his method with great success. Speaking of Houdin's wonderful Perception, Halleck says: "A wide-awake eagle would probably see more of a thing at one glance than would a drowsy lizard in a quarter of an hour. Extreme rapidity of Perception, due to careful training, was one of the factors enabling Houdin and his son to astonish everybody and to ama.s.s a fortune. He placed a domino before the boy, and instead of allowing him to count the spots, required him to give the sum total at once. This exercise was continued until each could give instantaneously the sum of the spots on a dozen dominoes. The sum was given just as accurately as if five minutes had been consumed in adding." Houdin, in his Memoirs relating the above facts regarding his own methods, states with due modesty, that many women far excel him in this respect. He says: "I can safely a.s.sert that a lady seeing another pa.s.s at full speed in a carriage will have had time to a.n.a.lyze her toilette from her bonnet to her shoes, and be able to describe not only the fashion and quality of the stuffs, but also say if the lace be real or only machine made."

There are a number of games played by children which tend to the cultivation of the Perception, and which might well be adapted for the use of older people. These games are based on the general principle of the various partic.i.p.ants taking a brief view of a number of objects displayed in one's hand, on a table, in a box, etc., and then stating what he or she has seen. There will be noticed a wonderful difference in the degree of Perception manifested by the various partic.i.p.ants. And, equally interesting will be the degrees of progress noted after playing this game over several times, allowing time for rest between the series of games. It is a fact well known in police circles that thieves often train boys in this way, following this course by another in which the lads are expected to take in the contents of a room, the windows, locks, etc., at a glance. They are then graduated into spies looking out the details of the scenes of future robberies.

In our volume of this series, devoted to the consideration of the Memory, we have related a number of exercises and methods, similar to those given above, by which the Perception may be cultivated. Perception plays a most important place in memory, for upon the clearness of the percepts depends to a great degree the clearness of the impressions made upon the memory. So close is the connection between Memory and Perception that the cultivation of one tends to develop the other. For instance, the cultivation of the Memory necessitates the sharpening of the Perception in the direction of obtaining clear original impressions; while the cultivation of Perception naturally develops the Memory by reason of the fact that the latter is used in testing and proving the clearness and degree of Perception. This being the case, those who find that the exercises and methods given above are too arduous may subst.i.tute the simple exercise of remembering as many details as possible of things they see. This effort to impress the memory will involuntarily bring into action the perceptive faculties in the acquirement of the original impressions, so that in the end the Perception will be found to have developed.

Teachers and those having to do with children should realize the great value of the cultivation of Perception in the young, and thus establishing valuable habits of observation among them. The experience and culture thus acquired will prove of great value in their after life.

As Brooks well says on this subject: "Teachers should appreciate the value of the culture of the perceptive powers, and endeavor to do something to afford this culture. Let it be remembered that by training the powers of observation of pupils, we lead them to acquire definite ideas of things, enable them to store their minds with fresh and interesting knowledge, lay the foundation for literary or business success, and thus do much to enhance their happiness in life and add to the sum of human knowledge."

CHAPTER VII.

REPRESENTATION

Sensation and Perception, as considered in the preceding chapter, are what are called by psychologists "Processes of Presentation." By Presentation is meant the direct offering to the consciousness of mental images or objects of thought. If there were no faculty of the mind capable of retaining and _re_-presenting to the consciousness the impression or record of Perception, we could never progress in knowledge, for each percept would be new each time it was presented and there would be no recognition of it as having been previously perceived, nor would there be any power to voluntarily recall any percept previously acquired. In short, we would be without that power of the mind called Memory.

But, fortunately for us as thinkers, we possess the power of Representation; that is, of reproducing past perceptions and experiences in the shape of _mental images_ or pictures, "in the mind's eye," so to speak, which relieves us of the necessity of directly and immediately perceiving an object each time we desire or are required to think of it.

The processes whereby this becomes possible are called the processes of Representation, for the reason that by them past experiences of Perception are _re_-presented to the consciousness.

The subject of Representation is closely bound up with that of Memory.

Strictly speaking, Representation may be said to be one phase of Memory; a.s.sociation of Ideas another; and the authorities prefer to treat the whole subject under the general head of Memory. We have written a work on "Memory" which forms one of the volumes of the present series, and we have no intention, or desire, to repeat here the information given in that work. But we must consider the subject of Representation at this point in order to maintain the logical unity of the present general subject of Thought-Culture. The student will also notice, of course, the close relation between the processes of Representation and those of the Imagination, which we shall consider in other chapters of this work.

Memory has several phases, the usual cla.s.sification of which is as follows: (1) Impression; (2) Retention; (3) Recollection; (4) Representation, and (5) Recognition. Each phase requires the operation of special mental processes. _Impression_ is the process whereby the impressions of Perception are recorded or stamped upon the subconscious field of mentality, as the impress of the die upon the wax. _Retention_ is the process whereby the subconsciousness _retains_ or holds the impressions so received. _Recollection_ is the process by which the mind _re-collects_ the impressions retained in the subconsciousness, bringing them again into consciousness as objects of knowledge. _Representation_ is the process whereby the impressions so re-collected are _pictured or imaged_ in the mind. _Recognition_ is the process whereby the mind _recognizes_ the mental image or picture so re-presented to it as connected with its past experience.

As we have stated, we have considered the general subject of Memory in another volume of this series and, therefore, shall not attempt to enter into a discussion of its general subject at this place. We shall, accordingly, limit ourselves here to a brief consideration of the phase of Representation and its cultivation.

Representation, of course, depends upon the preceding phases of Memory known as Impression, Retention and Recollection. Unless the Impression is clear; unless the Retention is normal, there can be no Representation. And unless one _recollects_ there can be no Representation. Recollection (which is really a re-collection of percepts) must precede Representation in the shape of mental images or pictures. Recollection re-collects the mental materials out of which the image is to be constructed. But, as Brooks says: "It is not to be a.s.sumed that knowledge is retained as a picture; but that it is _recreated_ in the form of a picture or some other mental product when it is recalled." The process is a.n.a.logous to the trans.m.u.tation of the sound-waves entering the receiver of a telephone, into electrical-waves which are transmitted to the receiver, where they are in turn re-trans.m.u.ted to sound-waves which enter the ear of the listener. It will be seen at once that there is the closest possible relation between the processes of Representation and those of Memory--in fact, it is quite difficult to draw a clear line of division between them. Some make the distinction that Representation furnishes us with an exact reproduction of _the past_; while Imagination combines our mental images into _new products_. That is, Representation merely _reproduces_; while Imagination _creates_ by forming new combinations; or Representation deals with a reproduction of the Actual; while Imagination deals with the Ideal.

Wundt speaking of this difficult distinction says: "Psychologists are accustomed to define _memory images_ as ideas which _exactly reproduce_ some previous perception, and _fancy images_ as ideas consisting of a combination of elements taken from a whole number of perceptions. Now memory images in the sense of this definition simply do not exist....

Try, for instance, to draw from memory some landscape picture which you have only once seen, and then compare your copy with the original. You will expect to find plenty of mistakes and omissions; but you will also invariably find that you have put in a great deal which was not in the original, but which comes from landscape pictures which you have seen somewhere else."

While we generally speak of Representation _picturing_ the recollected percepts, still, we must not make the mistake of supposing that it is concerned with, or limited to, only mental pictures. We are able to _represent_ not only visual percepts but also sounds, smells, tastes or feelings, often so vividly that they appear as almost actually existent.

We may also even _represent_, symbolically the processes of reasoning, mathematical operations, etc. In short nearly, if not all experiences which are possible in Presentation are also possible in Representation.

The phase of Representation, in the processes of Memory, is of course subject to the general laws of the Cultivation of Memory which we have stated in detail in our previous volume on that subject. But there are some special points of development and cultivation which may be considered briefly in this place. In the first place the importance of Attention and clear Perception, as necessary precedents for clear Representation, may be emphasized. In order to form clear mental images of a thing we must have perceived it clearly in the first place. The advice regarding the use of the Attention and Perception given in preceding chapters need not be repeated here, but special attention should be directed toward them in connection with the processes of Representation. If we wish to cultivate the Representative faculties, we must begin by cultivating the Presentative faculties.

Then again we must remember what we have said elsewhere about the facts of development through (1) Use; and (2) Nourishment, in all mental faculties. We must begin to _use_ the faculties of Representation in order to exercise them. We must give them _nourishment_ in the shape of objects of mental food. That is to say we must furnish these faculties with _materials_ with which they may grow and develop, and with exercise in order to strengthen the mental-muscle and also to give the faculties the opportunity to "acquire the knack." The exercises and methods recommended in our chapter on Perception will furnish good _material_ for the Representative faculties' growing requirements. By _perceiving_ the details of things, one is able to reproduce clear mental images of them. In studying an object, always carry in your mind the fact that you wish to _reproduce_ it in your mind later. In fact, if you have the opportunity, let your mind "repeat it to itself" as soon as possible after the actual occurrence and experience. Just as you often murmur to yourself, or else write down, the name of a person or place which you have just heard, in order that you may recollect it the better thereafter, so it will be well for you to "mentally repeat" to yourself the experiences upon which you wish to exercise your Representative faculties.

As to the matter of development and cultivation by Use, we would advise that you begin gradually to train your mind to _reproduce_ the experiences of the day or week or month, at intervals, until you feel that you are developing a new power in that direction. Tonight, if you try you will find that you can reproduce but a very small part of today's happenings with any degree of clearness. How clearly can you image the places you have been, the appearances of the people you have met, the various details of persons and things which you perceived during the experiences of the day? Not very clearly, we dare say. Try again, and you will find that you will be able to add new details. Keep it up until you feel tired or think that you have exhausted all the possibilities of the task. Tomorrow, try it again, and you will find that the second day's experiences are more clearly reproduced in your mind. Each day should find you a little more advanced, until you get to a place where the normal degree of power is attained, when the advance will be slower.

Then, at the end of the week, review its experiences. Do the same the following week. At the end of the month, take a hasty mental trip over the month's experiences. And so on. Exercise, in moderation, along these lines will work wonders for you. Not only will it develop the Representation, but your powers of observation and your general memory will be found to be improved. And, moreover, in "chewing the mental cud"

you will think of many things of interest and importance in connection with your work, etc., and your general mental efficiency will be increased for the faculties of the mind are interdependent and share benefits with each other.

CHAPTER VIII.

ABSTRACTION

As we have seen, the first stage or step in the process of Thought is that called Perception, which we have considered in the preceding chapter. Perception, as we have seen, is the process by which we gain our first knowledge of the external world as reported to us by the channels of sense. The Perceptive faculties interpret the material which is presented to us by the senses. Following upon Perception we find the processes resulting from the exercise of the group of faculties which are cla.s.sified under the general head of Understanding.

Understanding is the faculty, or faculties, of the mind by means of which we intelligently examine and compare the various _percepts_, either separating them by a.n.a.lysis, or else combining them by synthesis, or both, and thus securing our general ideas, principles, laws, cla.s.ses, etc. There are several sub-phases of Understanding which are known to psychologists and logicians as: (1) Abstraction; (2) Conception or Generalization; (3) Judgment, and (4) Reasoning, respectively. In this chapter we shall consider the first of these sub-phases or steps of Understanding, which is known as "Abstraction."