In the preceding volume, entitled "Making Your Own World," you learned that reaction-time is the interval that elapses between the moment when a sense-vibration reaches the body and the moment when perception is made known by some outward response.

Reaction-time can be made to furnish a clue to the adaptability of the individual for any business, profession or vocation.

To determine the character, accuracy and rapidity of the mental reactions of different individuals under different conditions, various scientific methods have been evolved and cunning devices invented.

There are decisive reaction-time tests by which you may readily map out your own mentality or that of any other person, including, for instance, those who may seek employment under you.

Have you been harboring the delusion that "quick as thought" is a phrase expressive of flash-like quickness? Have you had the idea that thought is instantaneous? If so, you must alter your conceptions.

The fact is that your merely automatic reactions from sense-impressions can be measured in tenths of a second, while a really intellectual operation of the simplest character requires from one to several seconds.

An important thing for you to know in this connection is that no two people are alike in this respect. Some think quickly along certain lines; some along other lines.

And the man or woman that you need in any department of your business is that one whose mind works swiftly in the particular way required for your business.

How rapidly does your mind work? How fast do your thoughts come, compared to the average man in your field of activity?

How fast does your stenographer think? Your clerk? Your chauffeur? Are they up to the average of those engaged in similar work? If not, you had best make a change.

A large number of tests and mechanical devices, some of them most complicated, have been scientifically formulated or invented to measure the quickness of different kinds of mental operations in the individual.

One very simple test which we give merely to illustrate the principle is called the "Test of Uncontrolled Association." All the materials needed for this test are a stop-watch and a blank form containing numbered spaces for one hundred words.

Give these instructions to the person you are examining: "When I say 'Now!' I want you to start in with some word, any one you like, and keep on saying words as fast as you can until you have given a hundred different words. You may give any words you like, but they must not be in sentences. I will tell you when to stop." You then start your stop-watch with the command "Now!" and write the words on the blank form as fast as they are spoken. Mere abbreviations or shorthand will suffice. When the hundredth word is reached, stop the watch and note the time.

The average time for lists of words written in this fashion is about 308 seconds.

This is a fair test of the rapidity of the associative processes of the mind. It will reveal many strange and characteristic idiosyncrasies. On the other hand, considering the vast number of words available, it is remarkable to note the degree of community to be found in the words that will be given by a number of persons. Thus, "in fifty lists (5,000 words) only 2,024 words were different, only 1,266 occurred but once, while the one hundred most frequent words made up three-tenths of the whole number."

Professor Jastrow, of Wisconsin University, has found also that the "class to which women contribute most largely is that of articles of dress, one word in every eleven belonging to this class. The inference from this, that dress is the predominant category of the feminine (or of the privy feminine) mind, is valid, with proper reservations."

Another method of testing speed of thought is to pronounce a series of words and after each word have the subject speak the first word that comes to him. The answers are taken down and are timed with a stop-watch. About the quickest answers by an alert person will be made in one second, or one and one-fifth seconds, while most persons take from one and three-fifths to two and three-fifths seconds to answer, under the most favorable circumstances. Puzzling words or conflicting emotions will prolong this time to five and ten seconds in many cases. Much depends upon the kind of words propounded to the subject, starting with such simple words as "hat" and "coat," and changing to words that tend to arouse emotion. A list of words may be carefully selected to fit the requirements of different classes of subjects.

By appropriate tests, the quickness of response to sense-impressions, the character of the associations of ideas, the workings of the individual imagination, the nature of the emotional tendencies, the character and scope of the powers of attention and discrimination, the degree of persistence of the individual and his susceptibility to fatigue in certain forms of effort, the visual, auditory and manual skill, and even the moral character of the subject, can be more or less clearly and definitely determined.

It is possible by these tests to distinguish individual differences in thought processes as conditioned by age, sex, training, physical condition, and so on, to analyze the comparative mental efficiency of the worker at different periods in the day's work as affected by long hours of application, by monotony and variety of occupation and the like, and even to reveal obscure mental tendencies and to disclose motives or information that are being intentionally concealed.

Among the simplest of such tests are those for vision, hearing and color discrimination. Tests of this kind are now given to all applicants for enlistment in the army, the navy and the marine corps, and more exacting tests of the same sort are given to candidates for licenses as pilots and for positions as officers of ships.

Employees of railroads, and in some cases those of street railroads, also, are subjected to tests for vision, hearing and color-discrimination. In the case of trainmen the color-discrimination tests result in the rejection of about four per cent of the applicants. The tests are repeated every two years for all the men and at intervals of six months for those suspected of defects in color discrimination. In all of these cases the tests have for their object the detection and rejection of unfit applicants.

One of the earliest instances of work of this kind was the introduction a few years ago of reaction-time tests in selecting girls for the work of inspecting for flaws the steel balls used in ball bearings. This work requires a concentrated type of attention, good visual acuity and quick and keen perception, accompanied by quick responsive action. The scientific investigator went into a bicycle ball factory and with a stop-watch measured the reaction-time of all the girls then at work. All those who showed a long time between stimulus and reaction-time were then eliminated. The final outcome was that thirty-five girls did the work formerly done by one hundred and twenty; the accuracy of the work was increased by sixty-six per cent; the wages of the girls were doubled; the working day was shortened from ten and one-half hours to eight and one-half hours; and the profit of the factory was substantially increased.

To illustrate the methods employed and the importance of work of this kind, we quote the following from the recent ground-breaking book, "Psychology and Industrial Efficiency," by Professor Hugo MÜnsterberg, of Harvard University. This extract is an account of Professor MÜnsterberg's experimental method for determining in advance the mental fitness of persons applying for positions as telephone operators. Such information would be of immense value to telephone companies, as each candidate who satisfies formal entrance requirements receives several months' training in a telephone school and is paid a salary while she is being trained.

One company alone employs twenty-three thousand operators, and more than one-third of those employed and trained at the company's expense prove unfitted and leave within six months, with a heavy resulting financial loss to the company. The tests are numerous and somewhat complicated and require more time to conduct them than tests in other lines of work, but for these very reasons will be particularly illuminating. Professor MÜnsterberg says:

"After carefully observing the service in the central office for a while, I came to the conviction that it would not be appropriate here to reproduce the activity at the switchboard in the experiment, but that it would be more desirable to resolve that whole function into its elements and to undertake the experimental test of a whole series of elementary mental dispositions. Every one of these mental acts can then be examined according to well-known laboratory methods without giving to the experiments any direct relation to the characteristic telephone operation as such. I carried on the first series of experiments with about thirty young women who a short time before had entered into the telephone training-school, where they are admitted only at the age between seventeen and twenty-three years. I examined them with reference to eight different psychological functions. *** A part of the psychological tests were carried on in individual examinations, but the greater part with the whole class together.

"These common tests referred to memory, attention, intelligence, exactitude and rapidity. I may characterize the experiments in a few words. The memory examination consisted of reading the whole class at first two numbers of four digits, then two of five digits, then two of six digits, and so on up to figures of twelve digits, and demanding that they be written down as soon as a signal was given. The experiments on attention, which in this case of the telephone operators seemed to me especially significant, made use of a method the principle of which has frequently been applied in the experimental psychology of individual differences, and which I adjusted to our special needs. The requirement is to cross out a particular letter in a connected text. Every one of the thirty women in the classroom received the same first page of a newspaper of that morning. I emphasize that it was a new paper, as the newness of the content was to secure the desired distraction of the attention. As soon as the signal was given, each one of the girls had to cross out with a pencil every 'a' in the text for six minutes. After a certain time, a bell signal was given, and each then had to begin a new column. In this way we could find out, first, how many letters were correctly crossed out in those six minutes; secondly, how many letters were overlooked; and thirdly, how the recognition and the oversight were distributed in the various parts of the text. In every one of these three directions strong individual differences were indeed noticeable. Some persons crossed out many, but also overlooked many; others overlooked hardly any of the 'a's,' but proceeded very slowly, so that the total number of the crossed-out letters was small. Moreover, it was found that some at first do poor work, but soon reach a point at which their attention remains on a high level; others begin with a relatively high achievement, but after a short time their attention flags, and the number of crossed-out letters becomes smaller or the number of unnoticed, overlooked letters increases. Fluctuations of attention, deficiencies and strong points can be discovered in much detail.

"The third test, which was tried with the whole class, referred to the intelligence of the individuals. *** The psychological experiments carried on in the schoolroom have demonstrated that this ability can be tested by the measurement of some very simple mental activities. *** Among the various proposed schemes for this purpose, the figures suggest that the most reliable one is the following method, the results of which show the highest agreement between the rank order based on the experiments and the rank order of the teachers. The experiment consists in reading to the pupils a long series of pairs of words of which the two members of the pair always logically belong together. Later, one word of each pair will be read to them and they have to write down the word which belonged with it in the pair." (For example, "thunder" and "lightning" are words that "logically belong together," while "horse" and "bricks" are unrelated terms.—Editor's note.)

"This is not a simple experiment on memory. The tests have shown that if, instead of logically connected words, simply disconnected chance words are offered and reproduced, no one can keep such a long series of pairs in mind, while with the words which have related meaning, the most intelligent pupils can master the whole series. The very favorable results which this method had yielded in the classroom made me decide to try it in this case, too. I chose for an experiment twenty-four pairs of words from the sphere of experience of the girls to be tested." (For instance, "door, house"; "pillow, bed"; "letter, word"; "leaf, tree"; "button, dress"; "nose, face"; "cover, kettle"; "page, book"; "engine, train"; "glass, window"; "enemy, friend"; "telephone, bell"; "thunder, lightning"; "ice, cold"; "ink, pen"; "husband, wife"; "fire, burn"; "sorry, sad"; "well, strong"; "mother, child"; "run, fast"; "black, white"; "war, peace"; "arm, hand."—Editor's note.)

"Two class experiments belonged rather to the periphery of psychology.

"The exactitude of space-perceptions was measured by demanding that each divide first the long and then the short edge of a folio sheet into two equal halves by a pencil-mark.

"And finally, to measure the rapidity of movement, it was demanded that every one make with a pencil on the paper zigzag movements of a particular size during the ten seconds from one signal to another.

"After these class experiments, I turned to individual tests.

"First, every girl had to sort a pack of forty-eight cards into four piles as quickly as possible. The time was measured in fifths of a second, with an ordinary stop-watch.

"The following experiment which referred to the accuracy of movement impulses demanded that every one try to reach with the point of a pencil three different points on the table in the rhythm of metronome beats. On each of these three places a sheet of paper was fixed with a fine cross in the middle. The pencil should hit the crossing point, and the marks on the paper indicated how far the movement had fallen short of the goal. One of these movements demanded the full extension of the arm and the other two had to be made with half-bent arm. I introduced this last test because the hitting of the right holes in the switchboard of the telephone office is of great importance.

"The last individual experiment was an association test. I called six words, like 'book,' 'house,' 'rain,' and had them speak the first word which came to their minds. The time was measured in fifths of a second only, with an ordinary stop-watch, as subtler experiments, for which hundredths of a second would have to be considered, were not needed.

"In studying the results, so far as the memory experiments were concerned, we found that it would be useless to consider the figures with more than ten digits. We took the results only of those with eight, nine and ten digits. There were fifty-four possibilities of mistakes. The smallest number of actual mistakes was two, the largest twenty-nine. In the experiment on attention made with the crossing-out of letters, we found that the smallest number of correctly marked letters was 107, the largest number in the six minutes, 272; the smallest number of overlooked letters was two, the largest 135; but this last case of abnormal carelessness stood quite isolated. On the whole, the number of overlooked letters fluctuated between five and sixty. If both results, those of the crossed-out and those of the overlooked letters, are brought into relations, we find that the best results were a case of 236 letters marked, with only two overlooked, and one of 257 marked, with four overlooked. The very interesting details as to the various types of attention which we see in the distribution of mistakes over the six minutes were not taken into our final table. The word experiments by which we tested the intelligence showed that no one was able to reproduce more than twenty-two of the twenty-four words. The smallest number of words remembered was seven.

"The mistakes in the perception of distances fluctuated between one and fourteen millimeters; the time for the sorting of the forty-eight cards, between thirty-five and fifty-eight seconds; the association-time for the six associated words taken together was between nine and twenty-one seconds. The pointing experiments could not be made use of in this first series, as it was found that quite a number of participants were unable to perform the act with the rapidity demanded.

"Several ways were open to make mathematical use of these results. I preferred the simplest way. I calculated the grade of the girls for each of these achievements. The same candidate who stood in the seventh place in the memory experiment was in the fifteenth place with reference to the number of letters marked, in the third place with reference to the letters overlooked, in the twenty-first place with reference to the number of word pairs which she had grasped, in the eleventh place with reference to the exactitude of space-perception, in the sixteenth place with reference to the association-time, and in the sixth place with reference to the time of sorting. As soon as we had all these independent grades, we calculated the average and in this way ultimately gained a common order of grading.***

"With this average rank list, we compared the practical results of the telephone company after three months had passed. These three months had been sufficient to secure at least a certain discrimination between the best, the average, and the unfit. The result of this comparison was on the whole satisfactory. First, the skeptical telephone company had mixed with the class a number of women who had been in the service for a long while, and had even been selected as teachers in the telephone school. I did not know, in figuring out the results, which of the participants in the experiments these particularly gifted outsiders were. If the psychological experiments had brought the result that these individuals who stood so high in the estimation of the telephone company ranked low in the laboratory experiment, it would have reflected strongly on the reliability of the laboratory method. The results showed, on the contrary, that these women who had proved most able in practical service stood at the top of our list. Correspondingly, those who stood the lowest in our psychological rank list had in the mean time been found unfit in practical service, and had either left the company of their own accord or else had been eliminated. The agreement, to be sure, was not a perfect one. One of the list of women stood rather low in the psychological list, while the office reported that so far she had done fair work in the service, and two others, to whom the psychological laboratory gave a good testimonial were considered by the telephone office as only fair.

"But it is evident that certain disagreements would have occurred even with a more ideal method, as on the one side no final achievement in practical service can be given after only three months, and because on the other side a large number of secondary factors may enter which entirely overshadow the mere question of psychological fitness. Poor health, for instance, may hinder even the most fit individual from doing satisfactory work, and extreme industry and energetic will may for a while lead even the unfit to fair achievement, which, to be sure, is likely to be coupled with a dangerous exhaustion. The slight disagreements between the psychological results and the practical valuation, therefore, do not in the least speak against the significance of such a method. On the other hand, I emphasize that this first series meant only the beginning of the investigation, and it can hardly be expected that at such a first approach the best and most suitable methods would at once be hit upon. A continuation of the work will surely lead to much better combinations of test experiments and to better adjusted schemes."

Analytical test studies such as the foregoing form an almost infallible means for finding out the unfit at the very beginning instead of after a long and costly experimental trying-out in vocational training-school or in actual service.

Whatever your line of business may be, you may rest assured that an analysis of its needs will disclose numerous departments in which specific mental tests and devices may be employed with a great saving in time and money and a vastly increased efficiency and output of working energy.

Suppose that you are the manager of a street railroad employing a large number of motormen. Would it not be of the greatest value to you if in a few moments you could determine in advance whether any given applicant for a position possessed the quickness of response to danger signals that would enable him to avoid accidents? Think what this would mean to the profits of your company in cutting down the number of damage claims arising from accidents! Some electric railroad companies have as many as fifty thousand accident indemnity cases per year, which involve an expense amounting in some cases to thirteen per cent of the annual gross earnings. Yet a comparatively simple mechanism has been devised for determining by the reaction-time of any applicant whether he would or would not be quick enough to stop his car if a child ran in front of its wheels.

The general employment of this test would result in the rejection of about twenty-five per cent of those who are now employed as motormen with a correspondingly large reduction in the number of deaths and injuries from street-car accidents. And on the other hand, the general use of psychological tests in other lines of work would make room for these men in places for which they are peculiarly adapted and where their earning power would be greater.

If, for example, the applicant responds to the signs of an emergency in three-fifths of a second or less, and has the mental characteristics that will enable him at the same time to maintain the speed required by the schedule, he may be mentally fitted for the "job" of motorman; while if it takes him one second or more to act in an emergency, he may be a dangerous man for the company and for the public.

Two-fifths of a second difference in time-reactions may mark the line between safety and disaster. How absurd it is to trust to luck in matters of this kind when by means of scientific experimental tests you can accurately gauge your man before he has a chance to involve you or your company in a heart-breaking tragedy and serious financial loss!

You can readily see that very similar tests could be devised to meet the needs of the employer of chauffeurs, as, for example, the manager of a taxicab company, or the requirements of a railroad in the hiring of its engineers.

You should not employ as private secretary a person whose reactions indicate a natural inability to keep a secret. This quality of mind can be simply and unerringly detected by psychological tests.

One quality entering into the ability to keep a secret is the degree of suggestibility of the individual. That person who most quickly and automatically obeys and responds to suggested commands possesses the least degree of conscious self-control. The quality referred to is illustrated by the child's game of "thumbs up, thumbs down," and "Simon says thumbs up" and "Simon says thumbs down." Those persons who are unable to wait for the "Simon says," but mechanically obey the command "thumbs up" or "thumbs down" would be those least able to resist a trap artfully laid to compel them to disclose what they wished to conceal. Like efficiency in observation, attention and memory, however, suggestibility is specific, not general, in character—that is to say, persons may be easily influenced by certain kinds of suggestion while possessing a strong degree of resistance to other kinds. Consequently actual tests of this quality cannot be limited to one method.

For purposes of illustration, here is a simple form of what is known as the "line" test for suggestibility. The subject is seated about two feet away from and in front of a revolving drum on which is a strip of white paper. On this strip of white paper are drawn twenty parallel straight lines. These lines begin at varying distances from the left-hand margin. Each of the first four lines is fifty per cent longer than the one before it, but the remaining sixteen lines are all of the same length.

The examiner says to the subject, "I want to see how good your 'eye' is. I'll show you a line, say an inch or two long, and I want you to reproduce it right afterwards from memory. Some persons make bad mistakes; they may make a line two inches long when I show them one three inches long; others make one four or five inches long. Let's see how well you can do. I shall show you the line through this slit. Take just one look at it, then make a mark on this paper [cross-section paper] just the distance from this left-hand margin that the line is long. Do that with each line as it appears."

The lines are then shown one at a time, and after each is noted it is turned out of sight. As the lines of equal length are presented, the examiner says alternately, "Here is a longer one," "Here is a shorter one," and so on. The extent to which these misleading suggestions of the examiner are accepted and acted upon by the subject in plain violation of the evidence of his senses tests in a measure his suggestibility, his automatic, mechanical and immediate responsiveness to the influence of others and his comparative lack of strong resistance to such outside influences. Inability to satisfactorily meet this and similar tests for suggestibility would indicate an unfitness for such duties as those required by a private secretary, who must at all times have himself well in hand and not be easily lured into embarrassing revelations.

You should not employ as stenographer a person whose time-reactions indicate a slowness of auditory response or an inability to carry in mind a long series of dictated words, or whose vocabulary is too limited for the requirements of your business.

The quickness of auditory response may be determined either by speech tests or by instrumental tests. In either case the acuteness of hearing of the applicant is measured by the ability to promptly and correctly report sounds at various known ranges, the acuity of the normal ear under precisely similar conditions having been previously determined. Speech involves a great variety of combinations—of pitch, accent, inflection and emphasis. Consequently a scientific speech test involves the preparation of lists of words based upon an analysis of the elements of whispered and spoken utterance. This work has been done, and such lists and tests are available.

For testing the ability to remember a series of dictated words the following lists of words are recommended:

The examiner should repeat these lists of words to the subject one at a time, alternating the concrete and abstract lists. To insure the presentation of the words with an even tempo, a metronome may be had by simply swinging a small weight on a string, having the string of just sufficient length so that the beats come at intervals of one second. Each word should be pronounced distinctly in time with the beat of the metronome, but without rhythm. After each list has been pronounced, have the subject write the list from memory. The lists thus made up by the subject from memory are then to be inspected with reference to the following points:

1. Memory errors (omissions and displacements), concrete lists.

2. Memory errors (omissions and displacements), abstract lists.

Every omission counts two errors; every displacement counts two-thirds when the displacement is by one remove only, one and one-third when by more than one move.

3. Insertions. These are words added by the subject. They count for two errors each, unless the added word resembles the word given in sound, in which case it counts one and one-third.

4. Perseverations. These are reproductions in a given series of words already given in a previous series. If frequent, this indicates a low order of intelligence, with weak self-control and poor critical judgment. Each perseveration counts four.

5. Substitution of synonyms, when a word of like meaning but different sound is substituted for the word given; counts one and one-third.

An approximate determination of the range of vocabulary of your prospective stenographer can be had by the use of the following comparatively short and simple test.

Hand the applicant a printed slip bearing the list of one hundred words given here and ask him to mark the words carefully according to these instructions.

Place before each word one of these three signs:

(I) A plus sign (+) if you know the word.

(II) A minus sign (-) if you do not know the word.

(III) A question mark (?) if you are in doubt.

When you have finished, count the marks and fill out these blanks, making sure that the numbers add to one hundred.

By adding find the total number of "plus" marks on the applicant's slip. Multiply this number by 280, and you will then have obtained the applicant's absolute vocabulary.

An absolute vocabulary of twenty thousand words or over may be graded as excellent; 17,500 to 20,000 words, good; 15,000 to 17,500, fair; and below 15,000, poor.

You should not employ as train-dispatcher a person whose time-reactions indicate a tendency to confuse associated ideas. The associated ideas may be related in time, place or a variety of ways, and the memory of one who has an inherent tendency to substitute an associate for the thing itself is a treacherous instrument. The tendency to confuse associated ideas can be measured by psychological tests.

Your own knowledge of the work of the world will suggest other employments besides that of train-dispatcher in which such a test could be used in hiring men to the improvement of the service.

The employment of psychological tests in the detection of crime is fast supplanting the brutalities of the "third degree."

Thus, for example, by the use of highly sensitive instruments we are able to detect the quickened heart-beat, the shudder, and other evidences of emotion not otherwise discernible, but due to the deliberate presentation of the details and evidences of a crime. Though the subject may not himself be aware of the slightest physical expression of emotion, these signs of a disturbed mentality are unerringly revealed by the delicate instruments of the psychologist.

In some factories the operative is called upon to simultaneously keep watch over a large number of parts of a moving mechanism, and to note and quickly correct a disturbance in any part. Eye and ear must have a wide range, must be able to take account of a large number of operations widely separated in space.

For the scientific determination of the operative's range of visual attention, the "disc tachistoscope," shown facing page 106, may be used. This is a form of short-exposure apparatus. The essential idea is to furnish a field upon which the subject may for a moment fasten his attention, and then to substitute for this field another containing certain prepared test-material. This last field is exposed for but a brief instant and removed, and the subject is then called upon to report all that he has seen during the last exposure. Tests of this kind have demonstrated that the range of visual attention is a comparatively constant quantity with each individual, having but little relation to general ability or intelligence and being but little affected by practice.

It matters not how painstaking the individual may be, he will fail in a test of this kind and at work of this kind if the type of attention that Nature gave him is unfitted for such an "expanded" watchfulness. Yet in any type of work requiring a focusing of the attention upon a minute operation so as to note nice discriminations and detect subtle differences, he might prove a most excellent worker.

The kind of apparatus, the method to be employed and the place for the experiment are all matters that vary with the conditions of the special problem. The apparatus may be simple and easily devised, or it may be intricate and the result of years of investigation and a large expenditure of money.

If there seems to you to be anything impracticable in the employment of tests in the manner we have indicated, please remember that for many years those seeking employment as railroad engineers have been required to pass tests for color-blindness, tests just as truly psychological as any that we have here referred to and differing from them only in respect to the character and complexity of the qualities tested.

Every calling can be analyzed and the mental elements requisite for success in that particular line can be scientifically disentangled. Methods for testing the individual as to his possession of any one or all of the mental elements required in any given vocation may then be devised in the psychological laboratory.

Furthermore, definite and scientific exercises can be formulated whereby the individual may train and develop special senses, faculties and powers so as the better to fit himself for his chosen field of work.

The use of the experimental method is new to every department of science. Crude and occasional experiments have marked the advance of physics, physiology and chemistry, but it is only with the recent innovation of the scientific laboratory that these sciences have made their greatest strides.

The employment of this method in dealing with problems of the mind is particularly new. So far as we are aware there is no school in all the world that employs definite and scientific exercises in the discipline and training of its pupils in power of observation, imagination and memory.

You have now completed a brief survey of the fundamental processes of the mind and seen something of the practical utility of this knowledge. You have before you "sense-perceptions," "causal judgments," "classifying judgments," and "associated emotional qualities" or "feeling tones." Every suggested idea, every act of reasoning is in the last analysis the product of one or more of these elementary forms of mental activity.

We shall now go on to consider the operations of these mental processes in connection with certain mental phenomena.

Our purpose in all this is not to teach you the elements of psychology as it is ordinarily conceived or taught. Our aim is to conduct you through certain special fields of psychological investigation, fields that within the past few years have produced remarkable discoveries of which the world, outside of a few specialists, knows little or nothing. In this way you will be fitted to comprehend the practical instruction, the application of these principles to practical affairs, toward which this Course is tending.

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