# Popular Science Monthly/Volume 73/September 1908/The Practical Value of Pure Science

Layout 4
* THE PRACTICAL VALUE OF PURE SCIENCE
By Professor THOS. H. MONTGOMERY, Jr.
UNIVERSITY OF PENNSYLVANIA
THROUGH all ages men have asked, What is worth while? The answer has been, at least from those not stupefied by pessimism, that many things are worth the while: happiness, self-respect, health, friendship, honor, wealth, all these are worth having, and any work that helps to secure them deserves the undertaking. It is the old question of what man should try to attain, and about it many a system of philosophy has reared itself, though for the most part on shaking legs.
Through this conflict of opinion we have come to pride ourselves upon being practical, even to such an extent as to consider abnormal any one who does not share this quality. To be practical means to be able to turn knowledge to useful account, to make of it some rather immediate application. With us Americans to be practical means too often to make and save money, forgetting that money is only a tool. Personally I would hold that man to be most practical who gets the most happiness out of life. But at the present we are concerned only with the question, that may seem a paradox, how can pure science be a practical undertaking?
Science in the strict sense, or pure science, is the search for the explanation of things. It is not the collecting of statistics, nor the cataloguing of them, nor the construction of systems, for however much these operations may help science, they do not compose it. Science is the light that points out what different phenomena have in common, and establishes their origins and changes. To-day the term is often taken in vain, as when we speak of pugilistic, tonsorial and domestic science, which shows that the general idea of it is any special skill or knowledge. But pure science, as strictly used, is much more than either skill or knowledge, it is explanation without any thought of immediate application to human needs.
How, then, is pure science practical, when it avowedly seeks no quick useful end? It is so, as its records show, by serving as the pioneer that makes possible utilitarian ends, it breaks a road through the unknown for application to follow. For not until science has given the explanation can we turn that explanation to use. And the examples that I shall proceed to relate show clearly that the pursuit of pure science has made possible many of the benefits that we now enjoy.
​It would be well worth while to stop to consider how much the various branches of engineering owe to pure mathematics and pure physics; or to relate the rise of numerous great industries that have grown out of the theoretical study of chemistry. Where would be our electric lighting and transportation but for the explanations of Franklin, Volta and Faraday? But I will limit myself to the practical value of pure science as exemplified by a particular one, biology. In making this restriction I should add that history tells how each of the pure sciences has led to useful ends, so that biology is but one of several cooperating sisters, each making her contribution to greater human happiness.
Biology has to explain the nature of living energies in treating of animals and plants and of man himself. Biology has to interpret processes, and this it attempts to do in a variety of ways according to the nature of the problem, the material and the bias of the thinker. Biology has to some extent grown up side by side with medicine; each helped the other in the days of their beginnings, and for that reason we may first treat its practical bearings to medicine.
In the seventeenth century the microscope came into use and it opened up, in the hands of Leeuwenhoek and Schwammerdamm, a wealth of unexpected detail. Leeuwenhoek exhibited his dissection of an ant to the delighted eyes of a king; since that time the tastes of royalty seem to have deteriorated. But such discoveries in the finer details of anatomy only presented new problems. The partial explanation came in 1838 with Schleiden and the following year with Schwann, who stated that animals and plants are built up of definite living units, the cells; that such units compose the tissues that had been determined by the physiologist Bichat, and that the organs are composed of definite layers of cells. The simplest animals, what we now call the Protozoa, were shown by Dujardin to be each composed of only a single cell. We define a cell as a particular mass of living substance regulated by a particular center, the nucleus. This view was strengthened by the notable researches of particularly von Kölliker and Max Schultze, and so gradually extended to all animals and plants as well as to the human body. Eduard van Beneden later finally settled the fact that the egg, the beginning of each many-celled animal, is itself a single cell. Thus biologists have come to concentrate their attention upon cell activities, and this cell unit has proved as fruitful in biology as the atom in chemistry, though the cell is something vastly more complex than many atoms. Now there grew up with this new doctrine Rudolf Virchow, the great master of the study of disease, and he it was who by placing the study of disease upon the cellular basis, by tracing diseased conditions to particular cells, laid the rational foundation of one branch of modern medicine. The investigation of the ​structure and function of cells is to-day regarded as the basis of research in medicine as well as in biology. Yet all of it is traceable to the dissection of an ant beneath a crude microscope! Surely nothing would have seemed less likely to have had practical bearings.
Such studies have given also the basis for embryology, the analysis of the development of the individual. Perhaps the greatest marvel of nature is the growth and change of the individual, a process that is ever before us, yet considered by. few. From a microscopic egg cell that shows but few differences in its various parts, grows up the adult body with its manifold organs; hairs and muscles, bones and lungs, these are not present as such in the egg cell, yet they gradually arise out of it and in the order of their use. The problem is: is such development regulated by energies of the egg cell, or by the operation of new stimuli and energies as the development proceeds? The marvel is the astounding precision of the process in spite of its complexity. When you eat your morning egg glance at the yellow yolk ball and note at one point of its surface a small white disc; that is the egg cell proper, all the rest is simply food for it. Now try to think out how that little disc produces the complex fowl, and you will agree that the problem is a much harder one than the fluctuations of stocks in your morning paper. This problem has also a close bearing on medicine, as William Harvey pointed out some three centuries ago and more, for the development of the human body is as important to the physician as its anatomy, because the anatomy is but one view of the individual, while the development represents the whole. To understand our own bodies we must know how they are formed, and to understand disease it must be traced to its origin. The changes from the egg cell to the adult demonstrate that the longer a part develops, the more precise and fixed it becomes, so that finally each particular part comes to have one definite structure, position and use. Malignant growths, then, probably have their causes most frequently early in development, due to misplacement of cells, temporary arrest of growth, undue rapid multiplication of cells, and other abnormalities. But this is not the place to attempt to classify diseases on an embryological basis, such as has been done by Minot. We need note here only that medicine is beginning to tread in the path made by biology, in recognizing that human disease as well as human anatomy must rest on the foundation of development.
Then, to understand our own bodies we have to explain them in terms of the structure of other animals, and many of our parts would be meaningless to us but for a knowledge of comparative anatomy. Our cankered vermiform appendix is represented in some animals by a large and serviceable attachment of the digestive tract, which explains it as a degenerate organ and therefore necessarily variable. Deep ​between the hemispheres of the brain is a little sac about the size of a pea, the pineal gland, and comparison shows that this was once a third eye. Sometimes an opening persists on the side of the neck below the jaw; in such a case one of the embryonic neck clefts has remained open, and this in turn has relations to the gill slits of a fish. All the ground plan of our bodies, the muscle cylinder within the skin, next the bony scaffolding, innermost the peritoneal sack around the viscera, all such relations would remain a mystery did we study only the human body. But in the light of comparative anatomy and embryology we recognize them as necessary parts of our heritage. Medicine must stand upon a thorough knowledge of the structure and processes of the human body, and before it can treat disorders it must understand states of health and their origin. Comparative anatomists and embryologists, the great men Harvey, Wolff, von Baer, Cuvier, Agassiz, Huxley, Cope and Gegenbaur, such men have not only broadened the field of human thought, but have also furnished the understanding of the human organism. They were all pure scientists, they did not have in mind the care and cure of the human body. Yet we might say they accomplished more for a rational medicine than all the physicians before them. How unlikely the prophecy seemed that any direct advantage would come to mankind from the researches of Harvey, Wolff and von Baer on the development of the chick, from those of Cuvier and Agassiz on fossils, or from those of Huxley, Cope and Gegenbaur on comparative anatomy. As the result of this change of thought we now see most medical schools prescribing biological courses, and choosing their professors of anatomy largely from the ranks of embryologists.
It is hardly necessary to state that it was Louis Pasteur who laid the foundation for the study of disease-producing organisms; indeed, he may be said to have done more for the human race, more to prevent physical misery, than any other man of the nineteenth century. He had in mind, first of all, the cure, but he realized that to accomplish this the mode of transmission of the disease must be understood. There have followed him a long line of investigators of bacterial diseases, and among them the purely scientific have done quite as much as the purely practical. In Russia there was a celebrated embryologist, Elias Metchnikoff, who worked out the life histories of a variety of animals, and was thereby led to a consideration of the part that the white blood cells play in the development. This brought him to the view that such cells are the guardian policemen of the body, that seek out and destroy the bacteria; and this to the further idea, that health is to be maintained and infection prevented by keeping the white blood cells in proper numbers and activity. Metchnikoff succeeded Pasteur at Paris, and though his theory of phagocytosis is far from all-sufficient, it has nevertheless strongly stimulated the study of bacteriology. His ​practical ideas grew out of his theoretical investigations of insects and worms.
Just at the present time the center of interest in medicine is the study of those infectious diseases produced not by bacteria, but by other one-celled germs, the animal protozoa. Among them are the blood parasites that produce malaria, yellow fever, syphilis and the terrible sleeping sickness of Africa, as well as the intestinal parasites of bloody dysentery; another one of them produces the Texas fever of cattle. Many investigators have contributed to our knowledge of these diseases since the time when Laveran discovered the germ of malaria, and prominent among them are the names of Grassi and Schaudinn. Grassi is professor of zoology at Borne, well known for his researches on the ancestry of insects, on the social communities of tbe white ants and on comparative anatomy; these researches on unpractical subjects furnished him with the method for attacking the malarial germ, and for making the marshes around Rome nearly free from that disease. Schaudinn worked at Berlin on the life histories of salt-water protozoa, discovering much of broad theoretical importance, indeed with much greater success than the long line of naturalists before him. He was no physician, he was a biologist, yet he ultimately attained one of the most desired medical chairs in Germany. His genius, and in a measure he is to be compared with Pasteur, lay in his success in unraveling complex life histories; he learned the method in studying the free-living forms, and therefore was enabled to work out the life histories of several that endanger the human body. He never had any direct interest in practical medicine, yet what help his work has brought to medicine! What he did in this direction, the zoologists Leuckart and Leidy did in another by their discoveries on the parasitic worms of man, and on the mode of infection; they all had little thought of practical application. Such biologists have taught pathologists that in the cure of any infectious diseases the first thing to be determined is the life history of the parasite, and this subject is a biological one.
Besides seeking the prevention of disease man has to meet the natural struggle for existence in another way, by securing food, and this means the nurture of his flocks and crops. Here again pure science has proved a valuable pioneer. Naturalists have long since recognized the close dependence of species upon each other, that what affects one comes in the long run to affect all. This is a dependence based upon the struggle for food. Remove one element, as one species, and a more or less general profound disturbance follows. Mankind is in no way exempt from this law. Decimate or extirpate a particular kind of insect-eating bird, and the insects that formed its diet will increase in numbers. Man will feel the disturbance should such insects happen to affect vegetation that is of human use. Remove the timber from ​mountain lands, and the available water will decrease, because the timber helps to hold the water supply and to prevent floods. In any way change the face of nature, as man by his habits must needs to do continually, and more or less serious results must follow. As an instance we may consider the cotton boll weevil, a subject that is a remarkably earnest one in Texas. This insect originated in Central America and has spread northward; several years ago the natural barriers to its spread were broken down and consequently it has extended its feeding area. When it first appeared in Texas all sorts of rough remedies were applied, but in vain; then the help of the National Department of Entomology of the Bureau of Agriculture was called in. They responded by sending down experts: not men trained in boll-weevil methods, for these had to be learned, but men with a good knowledge of general entomology, ready to attack the matter as they would any scientific problem. First they proceeded to determine the life history, egg-laying habits, duration of the different developmental stages, number of broods, overwintering; then, knowing these facts, they could decide at what stage the injury may be most successfully fought. The method is of the first importance and this was given by pure science, and in a way the method of meeting the boll weevil is not unlike the method of fighting a parasite of the human body. The next step was to ascertain the natural animal and plant enemies of the pest, and to try to increase these enemies. Thus the field mice in Russia have been reduced by infecting them with pathogenic bacteria, and the "green-bugs" of wheat by increasing the number of lady beetles. These are the general methods of meeting any such practical questions. Farmers may laugh at naturalists, but they are wholly dependent upon them when such emergencies arise. Most of us are likely to smile at the man who collects and describes insects, counting the number of joints in the antennas of a bug, of hairs upon the forehead of a bee, or the arrangement of the veins upon the wing of a moth. Most people would hold that such a being is wasting his time in a foolish hobby. But I wish to drive the fact very firmly home, that the collecting and naming of animals and plants, occupations that even many biologists pity, are really fundamental for biology and therefore for the sciences that rest upon biology. For the study of animals and plants had reached a standstill, a stagnation, for want of a proper concise method of naming the numerous species that were being made known, until the great Swede Linnæus, in the middle of the eighteenth century, by originating the modern method of naming plants and animals, indirectly made possible advance in agriculture as well as in biology. The more our knowledge advances the greater grows the need of accurate determinations of species. Without systematic describers of species agriculture would be a hopeless matter. Thanks to the labors of ​generations of pure scientists, working for the most part in obscurity, most of the insects in each civilized district have been described and named, and much has been made known concerning their habits. This knowledge is about as important a tool to the husbandman as is his plough.
In passing it need only be mentioned that the agitation for the protection of native birds, a movement that the farmers are at last beginning to support, originated not with agriculturists, but with scientific ornithologists. The farmer, left to his own prejudices, would kill all birds.
In another way pure science has aided agriculture, in improving varieties. The chief method in use is selection, planting each new generation from the seeds or cuttings of the best plants of the previous one; the most fit are selected and propagated. This method has been in use for more than a century, but it is only within the past fifty years that it has entered into general systematic employ. The man whose labors brought this method into dominance was Charles Darwin, who proved how important a factor selection is in the perpetuation and guidance of the changes of living beings. Now Darwin was not called a practical man; he was first an insect collector and geologist, then a traveler, lastly a most conscientious experimenter with an eye single to explaining. He discovered a natural factor in evolution, and illustrated it so fully on both wild and cultivated species that the world has accepted its truth. Before him men had applied selection rather unwittingly, on the general assumption that "blood will tell." After him they saw clearly into the workings of the principle, and now experiment with a fixed method. It is Darwin's method that the Department of Agriculture is trying to teach the farmers.
Then much work has been done to secure improvement by the crossbreeding or hybridizing of different varieties. It was Darwin again who was the first broadly scientific investigator of such inheritance. Take two plants or two animals which differ in one or more qualities and cross them, then it is to be expected that the hybrids will differ from the parents, and that a new strain or breed may be obtained that will prove more favorable for our particular purposes. Much of this kind of experimentation, perhaps the greater part, has been done so far by practical animal breeders and gardeners, and it was from such records that Darwin obtained much of his information. No one, for instance, has carried it out more extensively than Burbank, and he has had in mind marketable returns. Yet the theoretical study of hybridizing is coming to aid the other, and in time may come to direct it. Different kinds of inheritance are now distinguished, as blended inheritance, when the hybrid is intermediate between the two parents; mosaic, when it has some of the characters of the one and some of the ​other; alternate, when some of the hybrids are like one parent and some like the other; and the so-called unisexual inheritance, when all the hybrids tend to resemble one particular parent. Entirely new and unexpected fields of experimentation have been brought out by Mendel's study of alternate, and De Vries's examination of unisexual inheritance. This theoretical work also teaches that in practise attention should be given not so much to the whole individual as to the particular quality desired. The remarkable work of De Vries, the most important in evolution since the time of Darwin, would tend to show that though new forms may be produced by crossing, such crosses are usually not permanent, but tend to revert. De Vries's particular contention is that stable new forms, those that breed true, are not produced gradually by selection or otherwise, but arise suddenly and only in particular mutation periods. This introduces an entirely new attitude in the matters of selection and cross-breeding, and there can be no doubt that the scientific decision of these great problems will come to exert a great influence upon the progress of agriculture. It is the work of theorists that is here directing, stimulating and explaining, and it is changing the present haphazard experimentation, with its great loss of time and money, into accurate control.
If farmers would only do a little experimenting on their own account, each laying aside a small piece of ground for making tests, they would learn more of practical advantage than by following, year in and year out, the methods handed down by their forefathers. They would be doing a little scientific explanation, and though this might not immediately give them an additional bale of cotton, in time it would give them much more than that and would fill them with greater interest for their daily labors. The farmers are the backbone of the nation, and that spine must not get the rheumatism. A man must look before he leap, and science does the looking. As Franklin put it: "The eye of a master will do more work than both his hands." Indeed, the farmer comes into close touch with biological problems because his business is directly with plants and animals, and though he does not know it he is really a biologist in the rough. When the competition for market becomes keener, and it continues to do so as men become more trained, only he will be able to succeed who is armed with a working theory and by means of it aims at better results. In farming it is not the land so much as the man. To get at a new plan so as to use his time and brawn to the best advantage, the farmer must begin to explain and must use the explanations of science. A hen can not grow into a rooster, but it can be made to lay two eggs a day. The question of the qualities and possibilities of living beings is the subject-matter of biology, and the more we understand them the more we can use them. But we must remember that we can apply only when ​close study has suggested a method, and for that preliminary study to be effective it must not be hampered by the thought of immediate practical returns. Had Darwin in mind the improvement of domestic races of pigeons and poultry instead of the explanation of their origin, he would have contributed much less than he did to be put to practical use. Therefore the farmer should cease to look upon biology as an expense and luxury meant to entertain rich men's sons; he should recognize that any laboratory that is helping to analyze the energies of life is contributing something, indirect but none the less important, to further our usage of plants and animals.
These views are by no means generally held; they have to be taught. To transmit the new ideas of each generation is the business of teachers, and we may now discuss what kind of men make the best kind of teachers. To this I would answer that, other things being equal, the investigator makes the best teacher. For the teacher's duty is not so much to inform as to interest, and the greater interest he has in his own subject the greater influence he will be likely to have over his pupils. Clearly, then, the investigator should teach well because he has the enthusiasm to undertake the difficult task of advancing his subject. Further than this, he can best treat his subject because he has won knowledge for himself as well as through others, he most fully realize the difficulties and problems, and he should be the least likely to pin his faith to unfounded theories. On the other hand, that teacher can not have great influence who has learned simply from his school and college courses and from text-books, and who has not tried to penetrate into the fascinating field that lies beyond. Louis Agassiz was the greatest teacher of natural science that this country has yet enjoyed, and he was through and through an investigator; take the example of any man whose students have been led to follow his profession, and you will find he was an original thinker. One man may be a very storehouse of detailed information, yet be unable to teach, for too much knowledge is an impediment to clear thought. Another may be ignorant of many things, which is really a desirable quality, and because of his creative spirit of research be an inspiring teacher. The teacher's business is not to drill his students so that they soak in facts like so many sponges; but he should give them the wish to blossom and break into fruit of their own. Were encyclopedic knowledge the ideal, one generation would receive the knowledge of the preceding, no more, and the centuries when such conditions prevailed were well termed the dark ages. The teacher should create as well as transmit, for creation strengthens his teaching quality. Thus it happens that in the long run it is pure science that is forwarding every movement in general education. We find a parallel in the case of musicians: there are many with a good technique, but very few with the power to ​compose; the former are copyists and the latter creators. Now, what could the technicians do without the composers? Appliers are dependent upon fertile creators in general education as in music and other matters. It is pure science by which a man can advance his subject a little and arouse his students to do the same.
It may seem a sweeping statement, but I am inclined to believe that any advance in pure science helps to better our race, whether all of it can be practically applied or not. For so many practical uses have been made from what seemed unpromising theories, that we may confidently expect still more applications in the future. That is one side of the subject. The other and the more important is the growth of the method of science, to never rest content, but to seek to explain more and more. This means a continuous expansion of the field of thought and will prevent crystallization and stagnation. Just because human progress is to such great extent mental, creative thought should be held an important ideal, and this is the essence of science. Thus the mere pursuit of science, whether it be of direct material advantage or not, is by no means worthless to us, for it is a powerful factor in the progress of the human mind. I do not believe in the argument of the schoolmen, that a subject is to be studied for the mental training; life is too short for duties of that kind; what we need is the introduction of more subjects that enlarge our interests, and teach that there is a great deal under the sun that is new and inspiring. My particular argument may seem to many rather specious, yet I think that just in this point is pure science of great value. Men ask for quick, tangible results, for early harvesting of the crops. But that which is easiest and quickest need not be best. What influence each of us most deeply in our personal lives are intangible matters, feelings and desires that are hard to define and that are set apart from the daily occupation. Just so it is with our progress from generation to generation; it is the clarifying and ennobling thought rather than the dollar that gives the most enduring satisfaction whether we are ready to admit it or not. And if you ask proof for this statement, you may find it in any national biography where you discover the names of thinkers, not those of mere money-getters.
Our advance in civilization consists to large extent in the perfecting of the social state, and herein lies the important task of sociology. Numerous have been the proposals for bettering social conditions, and as great the clash of view, for such questions press on all of us. All admit the imperfection and injustice of present conditions, yet there is no general remedy in promise. The most we seem able to do is to mitigate here and there a few of the most urgent evils. It would seem that economists have dealt with only parts of the problem; they have spent much time in definitions, but so far have missed giving a scientific ​foundation to the whole subject. For in their examinations of human communities and governments they have limited themselves to man, and to large extent to man within the periods of graven and written history. The chief criticism that biology presses on sociology is that sociology has not yet taken the broad comparative and genetic method. The physician has learned that to understand the human body he must constantly make comparisons with the lower animals; indeed, the progress of medicine, as we have seen, is due to such a method. The psychologist is also recognizing that to explain human mental states he must go back of man; must trace mind from its beginnings, for biologists have shown that even the simplest one-celled animals exhibit memory, attention, volition as expressed by choice, and still other mental states. But so far the sociologist appears to have missed this method and has also failed to go back to the beginnings of the social state. Would you say that it seems ridiculous to expect complex social life among the lower animals? Biology has made known animal communities that in all respects are more fitted to their conditions of life and more harmonious than ever was human society. Nearly all conceivable social states are exhibited by animals. For there are associations of entirely different species of animals, even of animals with plants, the condition known as symbiosis, where each is necessary to the life of the other; this is a life partnership. There are quite opposite kinds of social conditions, parasitism, where the one gets most of the benefit and the other most of the injury; this animal parasite has its resemblance to the human plutocrat. Again, there are associations of individuals of the same species, societies that have developed out of the maternal instinct, the instinct of the mother to care for her young; the social state has arisen in such cases by the mother remaining with her young until the latter are full grown. The beginning of the family we find in the mother fish who guards the young against the father, or the spider who carries her young upon her back; endless are the curious instances of such single families. Out of these have arisen higher social states by the young remaining together after maturing, held together by the control of the mother. In the animals this is generally a matriarchate, or at least a feminine rule, for among the lower animals it is the males that have no suffrage. Thus has grown up that wonderful socialism of the honey bee, admired by men since the beginning of history. Here the queen mother is the single reproductive individual, wherefore she is guarded and fed; but save for her annual outburst, a pettishness allowed to royalty, when she leads a swarm out of the hive, she is virtually a prisoner and the government is carried out by the workers, who regulate the life of their queen more precisely than we are able to do by any written constitution, while at the same time they gather all the food, pasteurize and store it, nurse the young, secrete ​the wax and build of it the geometrical comb, even ventilate the hive. No wonder that men sit for hours in their gardens contemplating such organized unity. The drones, they represent a plutocracy, they have but one mission and when that is accomplished the workers kill them. Different wild bees and wasps exhibit various stages leading up to this complex state. Yet still more wonderful governments are known among the ants, with their different castes of workers, each with its particular set of occupations, with their more complex nests with granaries, dining-chambers and bed-rooms; with their habits of harvesting, of keeping milch cattle and providing stables for them, of cleansing the young, of growing and tending mushroom beds, true vegetable gardens beneath the earth, with even the habits of keeping slaves and guests. Ants also have a language by which they communicate their ideas to each other, not by articulate words, but by touch and smell; and certain solitary wasps are known that make use of a stone as a tool, a faculty generally supposed to be limited to mankind.
Now, such cases have been discovered by biologists, and biologists are analyzing their evolution. Pure science has made them known for the pleasure of the work and of the explanation. Yet it is not idle to suppose that such study may yet have its bearings on human social problems. Three practical men have turned with profit to the study of the social life of insects: McCook, the American preacher; Lubbock, the English parliamentarian, and Maeterlinck, the Belgian novelist. Robert Bruce got inspiration from a spider, and engineers have studied with profit the architectural skill of insects and spiders, particularly with regard to bridge making. The study of bees offers much more than the mere output of commercial honey. These lower animals show the real natural state of society, and make ridiculous Rousseau's wild imaginings. They have their trades, their agriculture and animal breeding, their guests and slaves, even their tools; they construct an eminently appropriate architecture with no waste of material, they store food and keep their cities clean and aseptic; some show even the beginnings of barter and exchange. Most of these occupations we generally suppose to be limited to ourselves, for we are nothing if not egotistic. The wonder of it is the perfect order and harmony, the excellence of the state. Willoughby was undoubtedly wrong in arguing that the state exists only in the case of man. Now, can sociology afford to disregard such data? Can the conflicting factors of human society be explained only by the study of man? Surely we ought to at least wrest from the insects their secret of perfect harmony. Many of man's occupations extend far back into nature, therefore to understand them we must trace them to the community life of lower animals, even back of this to the origin of the factor that made the family, the maternal instinct. Sociology has applied some of the teachings of pure science, ​such as the operation of selection and the struggle for existence. But if it is to have a scientific foundation it must base itself on the comparative study of community life.
I do not mean that the study of an ant family will give us any better system of taxation. But I do mean that the careful study of lower social states will lay a firmer basis to the general subject of sociology, and thus come to better human conditions. Then also our treatment of criminals must to large extent rest upon biology, for the main practical question involved is whether criminal traits and tendencies are inherited or whether they are learned. The whole subject of heredity is a biological one, and the outsiders who have ventured into this field have given no solutions. How we shall treat criminals and their children will depend upon the outcome of the theoretical investigation of heredity.
Much more might be said concerning the practical value of pure science, but I will mention only one more point, and that right briefly. It is ethical and is perhaps the most important of all. Science seeks the truth, and respects no opinion that does not represent the truth. Science is not so much materialistic as realistic, and it has to do only with what may be determined by experiment and observation. Like the every-day practical man, the scientist holds that those things that seem outside of himself are really outside, and not existent simply in his own mind; and he is striving to explain the relation of those things to each other and to himself. While confining himself to such subjects he does not, in fact, has no right to, imply that there are not other fields of thought. But with regard to the world of things, he claims the right to decide what is real and what is unreal. That man is valued the most in science who sees the truth most clearly, and states it most simply. Right or wrong in science is then a measure of the truth. The great outcome of scientific thought is the unity of all nature, and the great aim in view is the truth. Thoughts like these must come to profoundly modify systems of ethics. Science has a difficult road to travel, for it keeps pushing steadily onward into dark places. In the nature of the case it must make many mistakes, but it keeps the right ideal. The idea of the truth and the ways of reaching it may continue to change as they have in the past, but humanity can not go far wrong so long as it earnestly seeks the truth.
These matters are worth thinking about when there is so much discussion about the value of higher education. We hear protests against the cost of maintaining universities, and there are some people who honestly suppose that the higher seats of learning should be self-supporting. Indeed there was one college started in the east by a millionaire, and he was greatly surprised to find that he was to get no dividends. Education is never satisfied; it uses greedily all available ​funds, then calls for more. If an institution does not receive an increasing amount each year, it is not only standing still, but it is also going backward, for it gets more and more behind the times. Practical men are quite right in inquiring whether there is going to be some return to them out of this expenditure, and we have to answer them truthfully. Universities and museums and libraries, the centers of scientific activity, have enormous mouths that are always agape, like overgrown nestling birds. You put money into them, but you do not get money back, at least not directly. This point is very certain and there is no use trying to hide it. But what you do get back are ideas, new ideas. Much of the work represented by such institutions is scientific, and if you endow them you help to increase the ideas that make possible practical ends. You will notice that I have not been arguing for the prosecution of applied science, more properly, the applications of science, for the value of this is apparent to all. I have been speaking for the pursuit of pure science, because it is the necessary forerunner to any new practical application. This is the fact I wish to drive home because it is seldom understood. Scientists themselves often do not realize it, but think that pure science should be studied, even if it can never be made to touch the needs of human life. Men who are not scientists are apt to shrug their shoulders and to say that science may be interesting to some, but that they can not see the use of it and consequently can not see the value of education in pure science. So long as this remains the point of view, higher education and research must have the old hard road to travel. But if we will open our eyes to the fact that even pure science is really of useful value, and its history is proof of this, then the standing objection to higher education will be removed.