Fundamentals of Social Psychology
Chapter 34: Invention and Discovery
Emory S. Bogardus
A CONSIDERATION of originality, genius, and special aptitude naturally leads to the subjects of invention and discovery as phases of leadership. Invention is a concreting of originality and genius. It is the tangible evidence of the existence of superior ability; it is also the chief product of mental interaction. Invention means "seeing into;" and discovery, "coming upon;" one term emphasizes the subjective phase and the other the objective phase of the same process.
The history of invention and discovery is concerned not with "the unoriginal moments of any man's life, nor with the stolid procession that never had a thought of their own," but with the brightest, happiest, creative moments of the most fortunate minds of all races and in part with the most beneficent discoveries of mankind. Invention has occurred in all ages, among all peoples, from the most primitive to the most advanced.
The place of woman in making early inventions has been overlooked. Woman seems to have invented most of the arts. Woman probably discovered what herbs were edible, domesticated the cat, taught the dog to be a home guardian, discovered that cows and goats could give her children nourishing milk, was the first to think of winding reeds to make a cradle, wove linen, jute, and wool into body covering or clothes, invented baskets to collect the harvest in, was the first to think of firing clay in the heat of the sun in order to make bricks, discovered medicinal herbs, domesticated the silkworm, found what plants, animals, and methods could be utilized in making dyes and colors, and made countless household inventions. Primitive man's inventions dealt with the hunting and fighting life. They centered at first in weapons, implements, forms of barter, and later in business and government.
INVENTION AND IMAGINATION
Invention means coming upon, seeing into, and perceiving new relationships. A person with a number of habitual ideas on a given subject thinks
(395) along that line persistently and a new idea in the series "comes to him"—the result is an invention. One thinks about two unrelated sets of ideas until at some particular moment a "mental flash" occurs between the two lines of thought, the two are correlated—an invention has occurred.
To see a new relationship is the essence of invention. In ancient Babylon, individual characters were stamped upon brick, but it was not until centuries later that the simple process of putting the individual characters together and of substituting printing for writing was invented. According to Herodotus, Cyrus the Great was halted in his attack upon Babylon by the massive city walls, until he perceived a new relationship between the physical phenomena of the locality, whereupon he ordered the waters of the Euphrates turned aside, and sending his army along the river bed and under the walls of the city, he took by surprise the hosts of Nebuchadnezzar, who had not anticipated such a stratagem. When Heracles undertook the task of cleaning the Augean farmyard where 3000 oxen had been stabled for thirty years he perceived a new relationship; namely, that by turning the course of the Alpheus and Peneus rivers through the stables, the gigantic task would be accomplished in short order.
Imagination thus functions in invention by enabling one to perceive new relationships. Its "visionary" character is its greatest weakness, and its greatest strength, for without it no one could penetrate the Unknown that encircles, and no one could invent.
INVENTION AND PROBLEM-SOLVING
Inventing is problem-solving. Invention arises from personal and social needs, from problems, from attempts to extricate one's self from difficulties, from a reasonable degree of worrying. The starting point is a problem and its perception. I have seen a hundred students try to crowd through a set of double doors where one was closed, without showing evidences that a problem existed. Sometimes, one of the number, perhaps after nearly all the others have crowded through the single door, looks about, and unfastens the closed door, thus allowing the remaining persons to use the double aperture. In other words, most of us, most of the time are blind to many of our problems. We have them, and do not know it. The problem and its perception is an initial phase of the inventive process.
The next essential is an attitude of solving problems. Many people often would rather adjust themselves to an unsolved difficulty than to
( 396) try to unravel the tangled skein. In this connection the curiosity impulses function well. Curiosity culminates in invention; its natural trend is toward discovery. It is the inquiring mind which discovers, invents, creates. Inquiry, questioning, longing are the antecedents of inventions. It is the person who has no questions to ask who rarely invents. Questioning, which is so rampant, especially in children, is a precious trait, for it precedes invention. It is the inventive mind which is always characterized by problems—problems which incessantly call forth energy and produce mental focalization.
The desire to solve problems is normally followed by the collecting and analyzing of data. Scientific invention requires a thorough knowledge of all that has been discovered in the field of the given problem or problems. It also includes accurate methods of collecting new data, the making of theories on the basis of all available knowledge, and the testing of one theory after another by careful experimentation until a solution to the specific problem is found.
In this process the inventor may come upon an entirely unexpected and unsought for relationship ; the invention, or discovery, may be different from the one for which the search is made. In studying an apparatus designed to repeat Morse characters, Mr. Edison was looking for possible ways of improving the instrument when his attention was attracted to peculiar humming noises. He perceived a resemblance of these sounds to the human voice—and caught a vision which led to an unanticipated invention, the phonograph. Daguerre left an unexposed plate in a cupboard and later found that it was developed. He had not expected this result, but it led to an unforecasted discovery. He followed the new line of development. In the cupboard he found a capsule of mercury, a metal which discharges steam at ordinary temperature. He then experimented with underexposed plates and mercury—the daguerreotype was produced.
Problem-solving is fundamental to all invention and discovery. A need, a problem; concentration of attention upon the problem, the trial and error method of experimentation; finally, the expected or the unanticipated discovery—such is invention. Hence, the possibility of making useful inventions is open to almost any energetic mind.
It will now be clearer why psychologically there is no essential difference between inventing and discovering. Consider the discovery of America; first, there was a problem; namely, to travel by direct route to India; then the brilliant theory that Europe was related to or connected with India by the Western seas; the search, the long journey, the steadfast westward gaze, and the holding to the westward course against tremendous odds;
397) finally, land, not India, but a new continent. The process is
psychologically one with that of inventing.
THE NATURALNESS OF INVENTION
"Invention is as natural as imitation." Every imitation seems to be accompanied by at least a small degree of invention. Since the imitator sees life from a somewhat different angle from the initiator, and since he has somewhat different habitual reactions, he will unconsciously, if not deliberately, incorporate new elements into the process—new elements which are fundamental to all invention. Even the mere copying of the acts of another person is influenced by the personal equation of the imitator. It is almost impossible for one person to copy exactly the handwriting of another, except by diligent, painstaking, and concentrated effort. Hence invention and imitation are opposite poles of the same phenomenon; every imitation results in at least a slight modification or invention, and every invention leads to widespread imitation.
Inventing begins early in life. As soon as the child starts talking, he begins language invention. He names (a process of invention) his parents and himself (pa pa, ma ma, ba ba). He is alive with new and original potentialities. Parents and teachers have their minds set upon standardizing him, but in the necessary disciplining, the parent and even the teacher often neglect to study and to encourage his inventive ability. The unique phases of his personality are likely to receive no special attention unless they take the form of obstreperousness and recalcitrancy, and then, in most cases he receives repressive treatment.
On the other hand, scientific methods are developing, and special abilities are being diagnosed and stimulated. For example :
A public school teacher could do nothing with a small Italian boy who was unruly beyond description. The principal helplessly gave up the boy as not amenable to discipline and turned him over to a "special school." There the teacher quietly watched the newcomer when he was playing in the school yard. His special ability to sing expressed itself before the first day was over, and the wayward youth that same day played truant, singing for pay to older admirers in the new special school neighborhood. The special school teacher learned of these facts, and the next morning on the playground, without making reference to the previous day's truancy, asked: "Tony, can you sing anything from the Italian operas?" and in response, Tony sang La donna e mobile. "Would you like to take some music lessons?" asked the teacher. With tears quickly welling into his previously defiant eyes, his heart melted and his mind leaped with the flash and fire of a new enthusiasm—and yet an
(398) enthusiasm as old as the Italian race. He caused no more trouble to the school, and more important, his ability to reproduce, even to create art, and hence to invent, received recognition and effective stimulation.
In hearing new words and terms, the child commonly invents meanings for them. When he wrongly interprets something, he is apt to be scolded by his parents, who fail to see that what is a mistake to them is an invention by the child and that they may be repressing what is most creative in the child. The little girl who upon seeing a homely yellow cat, said : "There goes an orange meow," had made a crude and simple invention of terms. The child who wanted to be tucked into bed at night and said: "Tighten me up on both sides, Daddy," expressed in her own way an inaccurate but new connection of activities. In standardizing children there is danger of neglecting the inventiveness that crops out as naturally as does imitativeness. This danger lurks everywhere, from the methods of parental disciplining to the habit of some university instructors who grade high the students who simply memorize everything that the instructors expound.
Activity, initiative, assertion produce innovations. The activity expended in satisfying some desire or in securing an answer to some problem of the hour may have an important by-product in invention. Effort leads naturally to invention, especially if it be persistent and concentrated.
While invention may be as natural as imitation, it is immeasurably more difficult. The inventor frequently finds himself facing a stone wall, and it is only by faithful, concentrated effort in what seems at times as hopeless and endless experimenting that problems are solved and inventions made. Long, persistent mental effort is commonly the price of a worthwhile invention ; the lazy rarely initiate and invent. Almost all prominent inventors have been indefatigable workers. To invent is natural, but it requires labor.
THE INVENTIVE ATMOSPHERE
Invention is "catching." The spirit of invention spreads and inventive enthusiasm runs high, providing of course that intellectual activity prevails. Invention is easily multiplied by an inventive atmosphere.
Nations experience inventive epochs. An age of fashion, as opposed to one of custom, represents inventive craze as well as imitative craze. Behind countless superficial fashions is the spirit of invention, and out of the process a few worthy inventions are produced.
About the year 1500 there was a number of land discoveries—discovering land became the fashion. Land discoveries flocked together.
( 399) Since about 1915 an important series of air-transportation inventions have been made. Since 1920 radio inventions have followed one another in quick succession. One air-transportation or radio invention stimulates countless individuals to inventive efforts, and thus new records in these fields are continually being made.
The inventive atmosphere is largely created by social stimulation. A whole nation can pass into a social stupor, and individuals be put to sleep by social inertia, living and dying without becoming aware of needs which can be met by invention ; on the other hand, social activity and recognition promote the inventive spirit. Social satisfaction and stagnation kill inventiveness ; social recognition and rewards promote inventiveness.
Notice how business and large-scale industry have eagerly sought material
inventions, and how in consequence inventions in these fields have overshadowed
all others. Recognition of artistic ability in our country comes tardily, and
creative art as a result has been held back. Invention and creativeness in any
people respond to social stimulation.
INVENTION AND NECESSITY
Necessity, it is popularly said, is the mother of invention. By virtue of circumstances Robinson Crusoe became an inventor. Many a phlegmatic and unimaginative person has found himself in situations where he was obliged to invent. Exhaustion of productive lands compelled experimentation in dry farming and irrigation. An ultimate scarcity of crude oils will force the invention of a substitute for gasoline as a source of power for driving automobiles, and then of a substitute for the gasoline engine.
In all these cases it may be remembered that the "necessity" principle can
operate only because the basic inventions have already been made. No degree of
necessity could have produced the wagon until the wheel had appeared. No
invention on any particular level of complexity can be made until the
"underlying cultural base" has been built up.
INVENTION AND MODIFICATION
Invention is modification. Nearly all new ideas and appliances which reach the United States Patent Office are classified as improvements. In other words, an invention is usually a projection from a group of older inventions.
The invention of the steam engine was not made in its entirety in 1769 by James Watt ; neither did it take place on the day that the attention of Watt was centered on the rising and falling lid of the tea-kettle. The invention of the steam engine goes back to the ćolipile  made by Hero of Alexandria in the second century, B. C., to a type of steam windmill that was worked out by G. Branca about 1629, to the steam apparatus which was manufactured by the Marquis of Worcester in 1663, to the application of steam power to various kinds of machines by Thomas Savery about 1700, to Papin's idea of the piston, to Newcomen's piston engine, a model of which Watt was repairing when in 1763 he set to work to eliminate the waste of steam due to alternate chilling and heating of the cylinder. With this problem in mind, Watt worked for six years before he had perfected the separate condenser in 1769, the date at which it is popularly said that the steam engine was invented. This invention, therefore, involved more than the observation of a tea-kettle; it included countless improvements and modifications that had been made by many persons throughout a long period of time, and was itself a modification or improvement.
The modifications which constitute inventions are of three classes : (1) Natural evolutions, (2) transformations, and (3) marked deviations. Qualitatively, this order represents an ascending scale. The differences are chiefly of degree. As a result of the increasing difficulty that is involved, this schedule constitutes numerically, a decreasing scale.
1. Inventions that are natural evolutions of previously discovered relationships are the easiest to make and the most common. To change a gourd into a receptacle for carrying water, to use a stone as a weapon, to change a cave into a cave-house, or to give a slant to perpendicular windshields—these are natural evolutions. They range from innumerable small changes, scarcely worthy to be called inventions, to genuine transformations.
2. Some inventions are complex combinations of known relationships, and the results are transformations of the constituent elements. To connect a bucket and a rope with a wheel for the purpose of drawing water from a well, to attach a foot lever to a spinning wheel so as to change the immediate source of power and free the hand, or to put pneumatic tubes on wheels; these illustrate inventions which are transformations.
3. Marked deviations from current knowledge and skill are the highest forms which invention takes. They involve the recognition of relationships apparently unconnected. They range up into the most brilliant findings, conceptions, and creations of geniuses. The invention of the cipher, the discovery of fire, the application of steam to machinery, the making of an instrument for transmitting and reproducing human speech between points miles apart, the conception that the earth is round, the creation of a new national or a world epic ; such are a few examples of marked deviations. For fifteen cents Browning bought a dry-as-dust report of a Roman murder trial of 1689. Under his inventive touch this report was changed into ten poems, "each giving a different view of the case but all based upon the same fundamental facts." The product was The Ring and the Book.
The distinction between empirical invention and projected invention is important. The first is "perfected in use ;" the second is thought out abstractly before it is made objectively and concretely. Nearly all leading inventions today are first planned out and then tried out. J. M. Browning is credited with planning in all their details his two main types of machine guns, not in the shop, but in the desert, deliberately, without even putting pencil to paper. Plato's Republic is another form of projected invention, a large scale attempt to project a new organization of society.
One of the difficulties regarding projected inventions of societary forms is that of getting them fairly tested. Dr. Bernard suggests :
If any group of people, such as those of North Dakota or Russia or some colony of economic or social enthusiasts, are willing to subject themselves to the rigor of an experiment in trying out (such) theories of social revision or invention, it might properly be regarded as the sensible procedure for the rest of the world to feel grateful to them for trying the experiment, thus testing the workability of the theory. By saving us the trouble of making the test, they are doing us a favor instead of being our enemies.
THE INVENTION CYCLE
Inventions are cyclical ; that is, an ordinary invention passes through a cycle of existence. Tarde has recognized three stages in such a cycle—an incline, a plateau, and a decline.
(1) The incline is often very gradual. Inventions are sometimes ac-
( 402) -cepted with great reluctance and after long delays. The first steam engine, traveling at the fearful rate of ten or fifteen miles an hour was long considered by many people a work of the devil. The automobile has received readier acceptance. The steepness of the incline of common adoption depends upon the nature and the number of prejudices which must be vanquished and upon the quality of social interaction that is prevalent. A book that is far "ahead of the age" in which it appears will likely remain unaccepted during the life-time of the author. Beethoven died almost unknown. Mendel's laws of heredity were not recognized until forty years after their discovery.
(2) The plateau of an invention may be short or long, depending upon its usefulness and the nature of the mental interaction of the times. A "best seller" may remain such for only one month or it may continue such for twenty months. The bicycle enjoyed a short-lived popularity, because of the perfecting of the more serviceable automobile. The sailing vessel occupied first place for centuries as a means of ocean transportation —until the steamboat demonstrated its commercial utility.
(3) The decline may be abrupt, gradual, or extended over so many centuries as to be scarcely noticeable, or be swallowed up in the incline and plateau of a more complex and useful invention. As a rule the decline is gently sloping, for an invention that is widely adopted acquires the sanction of custom and convention and hence holds on with tenacity long after it has been superseded in serviceability by another invention. Inventions tend to become encased in the feelings and habits, and to outlive their usefulness. Superstitions are marked by a long drawn out and greatly attenuated decline. Occasionally, however, an invention is made, such as a new machine or a new industrial process, and established machines and processes are discarded suddenly.
There are many inventions which live on in slightly modified form, such as the ethical teachings of the New Testament, the metric system, the dress suit, the idea that the earth is spherical. Others survive as parts of new and better inventions, such as the wheel—in the wheelbarrow, the wagon, the automobile, the watch.
CUMULATIVE NATURE OF INVENTION
Inventions are cumulative; they lead to further inventing. Every valuable invention releases possibilities of further invention. Each is a cultural base for one, two, or more new inventions. Each is a call to some one to make further inventions. Inventions lead to inventions ; they come in
( 403) droves. They are not entirely sporadic, but follow one another in rough sequences.
Inventing may become habitual with certain individuals, for it is a process of concentrating one's psychic energy in a certain way toward certain goals. To look for new relationships in fields that one has mastered, and succeeded in once, twice, or more times, tends to create habits of seeing new relationships and thus of inventing. Thinking impulses may be organized in blind acceptance-habits, or of alert inquiring-habits. It is the latter that are basic to inventive habits, and which in turn create life occupations that are not easily forsaken. Edison will not voluntarily retire from inventing. Dr. Alexander Graham Bell, at the time of his death, was at work on a new invention; namely, a device whereby a pilgrim lost in a desert might save himself from dying of thirst by distilling water from his own breath.
The objective succession of inventions and discoveries is far from being accidental. America could hardly have been discovered by Europeans through conscious planning until the idea had been conceived that the earth is round. The sailing vessel could not have been invented before the boat; cooking processes, before the discovery of fire; the watch spring, before steel. An author makes use of words and ideas that have been discovered by others. He reads omnivorously and contacts other literary people, thus familiarizing himself with all the literary ideas and inventions of the past and present. Upon the basis of all these inventions he goes ahead trying himself out at some new undertaking, and writes a new book, or composes a new poem, and in so doing adds to the world's stock of literary inventions. There is a logic, therefore, of inventions as well as of argumentation.
No invention is complete and final. Every invention presages others. An invention is a potential parent of generations of unborn inventions. The pressure upon the truly imaginative, thoughtful person to invent is insistent. Persons are called, it would seem, to be joint creators with the Great Creator.
SOCIAL NEUTRALITY OF INVENTION
Inventions are socially neutral. They may destroy or reconstruct social relationships. Most new chemical discoveries can be used to human advantage or disadvantage. The invention of gunpowder, nitroglycerine, TNT, may be made the servants or the destroyers of mankind. The printing press is an instrument for carrying the best socialized teachings of the New Testament around the world, or to disseminate filth. The telephone
( 404) transmits lies or truth without discrimination. An aeroplane may carry food to dying children or bombs to blow them to bits.
Material inventions are usually socially neutral, and hence their social value depends on the attitudes of the people who control their use. As. material inventions increase, more and more powerful weapons thus are available for the use of evil-minded persons. The need for inventions that will stimulate socialized conduct and make it universal is imperative as material invention advances. There is danger of creating more powerful material inventions than we can control socially and spiritually. With every new advance in material inventions a concomitant advance is necessary in the field of socialized and spiritualized control of all inventions. If technical invention will ultimately "transform all mechanical work into supervision," then the need for the invention of a technique of socialized supervision is all-important.
INVENTION AND CIVILIZATION
Civilization is an invention. We live in a world of inventions. Through imitation, inventions are disseminated. Nearly all the elements of communication and social interaction are human inventions. Every word in this book is the invention of some one. The chair in which you are sitting; the pictures upon the walls ; the clothes you wear; the building which houses you; food, from the rolled oats or puffed wheat in the morning to the Neapolitan ice cream of the evening dinner are inventions. In eating, your hands and mouth are busy with inventions. The automobile, the office, the telephone, the radio, the newspaper, the church service, the marriage ceremony, Leybach's Fifth Nocturne—all are inventions. We live and move and have our being in a world of invention.
Civilization is a synthesis of inventions. How many invented processes are combined in the fountain pen or the typewriter with which we work, or in the radio to which we listen. Consider the combination of inventions in a baseball game. Who can disentangle and write the history of the inventions in the Constitution of the United States, in Shakespeare's Hamlet, or in the Bible.
Everything and every idea seem to bear the injunction: Let us invent. Educational systems have stressed imitative and copying processes, but scarcely tapped the possibilities of stimulating invention. Activity, initiative, interstimulation, focalization, invention, creation—this is the supreme logic of mental interaction.
THE EVOLUTION OF INVENTION
Inventions appear in human history on four main levels. In primitive groups the chief struggle is "to outwit nature." The Eskimos "must use the cunning of their eyes and their hands to convert animal life into the coin of the realm—food and fuel. The process makes them uncannily inventive. Out of apparent nothingness they create the necessities of life and a few luxuries." In these words from the story of Nanook of the North the lowest levels of invention are noted.
In the second level man is engaged chiefly in outwitting his fellow men. His inventions are those of securing egoistic control. He seeks leadership patterns for manipulating his fellows to his own advantage, and to "lord it" over his fellows.
Then, comes the level of inventions for securing group control. A person invents culture patterns whereby his group may rule other groups. Business groups seek to dominate in the nation, and nation groups struggle against one another for international control, but for purposes of group gain and power.
A fourth level now emerging is that of inventing means of serving without expectation of gain or reward. Patterns of conduct of this order are not yet well established, and are not easily recognized by most people, chiefly because they are living on one or more of the three lower levels of invention. Patterns of wholesome and stimulating cooperative efforts on a large scale are rare. A large expansion of inventions on this level is greatly needed.
1. Inventing is tangible evidence of inherited or acquired special abilities.
2. Inventing means seeing new relationships.
3. Imagination functions in inventions by depicting problems and possible solutions for them.
4. Inventing is problem-solving.
5. It is as natural to invent as to imitate, although the latter process is more difficult and less common.
6. Inventing is "catching," in the sense that one invention is a stimulus to make other inventions.
7. Invention sometimes results from necessity, if the cultural base for the specific invention has already been built up.
8. Most inventions are modifications of previously made inventions ; they are either natural evolutions, transformations, or marked deviations.
9. Inventions tend to run through cycles, which include an incline, plateau, and decline.
10. Inventions are cumulative, being built up step by step.
11.Inventions are socially neutral.
12. When material inventions tend to outrun spiritual ones, civilization is in grave danger.
13. Civilization is a composite of inventions.
14. The highest type of inventing is in the field of socialized processes.
1. What is invention?
2. Is inventive ability innate or acquired?
3. How is imagination related to invention?
4. In what way are inventions sometimes accidental?
5. What is the relation of invention to discovering?
6. If it is natural to invent, why do we not invent more than we do?
7. How early in life does invention begin?
8. What is meant by an inventive atmosphere?
9. When does necessity fail to lead to invention?
10. Explain : Inventions are modifications.
11. What is an invention cycle?
12. What is meant by the social neutrality of inventions?
13. How may an excess of material inventions over spiritual inventions be dangerous to society?
14. Explain : Civilization is invention.
1. Can you name anything that you daily use which is not an invention?
2. Why are so many persons who have made inventions unknown to us?
3. Explain: The time is ripe for an invention.
4. Explain : There are few persons who are fully qualified to use inventions.
5. Can you name an invention which is not used both for and against human welfare?
6. If Edison had lived as a native of Central Africa, what would have been the nature of his inventions?
7. Why are inventions characterized by cycles?
8. Describe the probable mental process which immediately preceded the invention of the bow and arrow.
9. How far can inventions be predicted?
10. What is the relation of invention to social interaction?
11. "Is it true that every invention opens up avenues for new forms of dishonesty ?"
12. Distinguish between invention and leadership.
13. Name an important invention that is greatly needed at the present time.
14. Why were more inventions made in the nineteenth century than in all previous centuries combined?
ASSIGNMENTS AND READINGS
Baldwin, J. M., Social and Ethical Interpretations (Macmillan, 1906), Chs. III, IV.
———. The Individual and Society (Badger, 1911), Ch. V.
Bernard, L. L., "Invention and Progress," Amer. Jour. of Sociology, XXIII : 1-33.
Knowlson, T. S., Originality (Lippincott, 1918).
Mach, E., "On the Part Played by Accident in Invention and Discovery." Monist: 161-175.
Mason, O. T., The Origins of Invention (Scribners, 1910).
Paulhan, F., Psychologie de l'invention (Paris, 1895).
Tanner, Amy E., "Certain Social Aspects of Invention," Amer. Jour. of Psychology, 26: 388-416.
Tarde, Gabriel, La Logique sociale (Paris, 1895), Ch. IV.
————, The Laws of Imitation (Holt, 1903), Ch. V.
Taussig, Frank W., Inventors and Money Makers (Macmillan, 1915), Chs. I, II.
Thomas, W. I., Source Book for Social Origins (Univ. of Chicago Press, 1909), Part III.
Todd, A. J., Theories of Social Progress (Macmillan, 1918), Ch. X.
Ward, L. F., Psychic Factors in Civilization (Ginn, 1906), Chs. XXVII, XXXI.
———, Applied Sociology (Ginn, 1916), Part II.
———, Pure Sociology (Macmillan, 1914), Chs. XVIII, XIX.
Wissler, Clark, The American Indian (Oxford Univ. Press, 1922), Ch. VIII.
———,"Relation of Culture to Environment from the Standpoint of Invention,"
Pop. Sci. Mon., LXXXIII : 164-68.