# Popular Science Monthly/Volume 16/December 1879/First-Hand and Second-Hand Knowledge

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* FIRST-HAND AND SECOND-HAND KNOWLEDGE.
By W. B. DALBY, F. R. C. S.
IN every system of education in which natural science forms no part, whatever knowledge the pupil gains is acquired from what he reads or from what he is told, and the truth of facts so presented to him he must take either upon trust or, in so far as they can be demonstrated to his reason, by logic or mathematics. In the study of natural science, on the other hand, he sees, he feels, he hears the same fact repeated again and again under the same conditions; and his informant is Nature—Nature, who never errs. Which is the better mode of acquiring information? Which information is the more likely to be true, to be the more worthy of trust, and safer to be acted upon? These questions need no reply. We shall all agree that one of the most important elements in education is English literature, and certainly in this department history must be included as not the least useful and delightful. But consider for a moment how entirely different, as a force in mental culture, is the information acquired by learning anything in science or in history. Take, for example, the character, or even the acts, of Mary Stuart. Although the events in her life occurred only some three hundred years ago, I dare say I could find among the students I am addressing as much difference of belief in many of her recorded actions, and certainly of opinion in regard to her character, as on any subject I could raise. To do this it would only be necessary to select a student fresh from the reading of Mr. Froude's history, and another who had derived his impressions from earlier histories, and had not laid aside the romance with which Scott's novels have surrounded this Queen. Mr. Froude's references to existing documents may be sufficient to induce me to receive his facts for purposes of history; but, accept his accounts as much as I will, my belief is of a very faint sort if I compare it with anything I have seen for myself. Viewed in the light of actual knowledge, the facts derived in the two ways have a different kind of value to me, both no doubt good in themselves, but still widely apart. With all due respect to the authorities at our old universities, I can not but think that the time will come when the elements of physiology and chemistry will be considered as valuable a method of mental training as the production of what are fancifully termed Latin verses, as the study of the traditional records of Jewish history, or the learning by heart of sentences from Paley's "Evidences." In the work which you now propose to undertake you will require no one's evidences but those of your own senses, and any statement from your teachers you will be able to subject to such tests. In whatever degree you do this your studies will be useful; when once ​you omit this they will be feeble and barren in their results. When you read or are told that an artery pulsates, that it is composed of so many coats, each possessing peculiar properties and uses, you will see and feel the artery to beat, you will examine its coats, you will see their properties exemplified in life, in death, in health, and in disease: in health, when it is divided by the knife, or tied to arrest hæmorrhage; in disease, when it is the seat of aneurism and other changes. Of what service would it be to you to read of all this? You would be better almost without such miserably insufficient information. Besides, what you read may not be true; you will decide for yourselves whether it is or not. If you wish to see the result of an education which makes a man arrive at an opinion accurately, act boldly, display manual dexterity, and effect good results, you may see it in any of the surgeons while deligating an artery to cure an aneurism. Again, supposing you to have made yourselves acquainted with the most complete account of typhoid fever, and simply to have supplemented what you have so learned by looking at any number of cases, and hearing what others have to say upon them. Until you have tested for yourselves the truth of all that you have heard or read about the disease, your knowledge would be worse than useless, for you might fancy that you know something about it, and, armed with such conceit, have the effrontery to take charge of a patient so suffering. When you have seen patients every day from the beginning to the end of the fever, have taken the temperature of their bodies and noted its variations, become so familiar with their pulses that you recognize the period at which it may be necessary to administer stimulants, examined the excretions, watched the changes in symptoms, noted the effects of treatment, observed every detail in diet and nursing, made yourselves acquainted with the affections which the fever leaves behind, witnessed the modes of death with patients who do not recover, examined the post-mortem changes in those who die from it, and, lastly (most important of all) have discovered the source whence the fever arose—if you have done all these things, your knowledge of the subject will be real, and you will have learned that, though books have their uses, they should in science and medicine be only used for the purpose of directing attention to what is to be looked for, and as a means of comparing the observations of others with your own. Thus far, then, books may be relied upon and no further. If this be so, the very essence and goodness of a scientific education is lost when a student endeavors to pass his examinations by learning from text-books what he should have taught himself by observation, and from pictures what he should have learned from realities. Those whose information is so gained have seized the shadow instead of the substance, and their work will for ever bear the marks of their indifferent education.
The results of the two modes of acquiring knowledge will be seen in the different classes of practitioners which they respectively ​produce. In the first order is the physician who intelligently studies physiology, who recognizes in pathology what I would, for the moment call an eccentric physiology; who says to himself when contemplating disease: "I here see such and such organs of the body out of order, such and such functions imperfectly performed; let me try to place these organs at rest, so that they may recover themselves (where recovery is possible) and perform, perhaps, in time their functions as heretofore"; who appreciates that in pneumonia the tendency is toward recovery when not interfered with, if the patient's strength is so supported that he can tide over the period during which the lung recovers itself; who sees in typhoid fever the same necessity for support, with the additional one of resting the intestine until the ulceration has time to heal; who, in the case of diseased kidneys, rests these organs by putting their work on to other organs, such as the skin and intestines, and allows no food which requires the special exercise of the kidneys for purposes of elimination. Similar management with other diseased organs. Here knowledge of physiology precedes knowledge of disease, and disease means to this physician disorded physiology. How different from the meddlesome apothecary of not long ago—never easy without he was pouring his medicines into his patient every few hours, having for every symptom a fresh drug which added to his patient's difficulties, and for every pain some outward application which increased his discomfort! Now, his modern counterpart is he who has learned chiefly from books and untrained observation what he knows of disease; for, please observe, that constantly seeing patients by no means implies that the faculty of accurately observing has been attained, and if this faculty is not acquired by a man early in life he will blunder on into old age. Such a one does much the same as his predecessor in a milder way when his first consideration takes the form of the inquiry, What is a good medicine for this, and what for that? He knows what will cure something or other, and so prescribes it. So well is what I am saying beginning to be understood that the very expression "cure," unless applied with a special meaning, as to an aneurism, a hernia, or the like, has become almost offensive, and will ere long be used only by the ignorant and pretentious. The physician does not pretend to cure his patients; he places them in the conditions most favorable to recovery, and is thus often the means of averting death and conducting them to health. You must not think that I am underrating the value of medicines; a large number of drugs we know well to be most useful and often necessaries in the treatment of disease, but the practice of ordering medicines to every patient who applies for relief is no longer the practice of physicians, although perhaps it may be followed by those who would on occasions be the last to resort to it, if they had the courage of their opinions. But pathology is better understood than it was a few years since, and with a more complete knowledge of morbid processes has ​come a corresponding knowledge of the frequent inability of drugs to control them; add to this that, with a fairly intelligent patient, the man who possesses an intimate acquaintance with the morbid change which produces the symptoms has the power of explaining his disease to him, and so successfully insisting upon the requisite conditions for treatment, irrespective sometimes of little, if any, assistance from drugs—such a knowledge can not be attained without a thorough scientific training, and I could multiply examples where this kind of education is as useful as it is to the physician.
At the risk of being tedious, I can not help repeating that the mental training which encourages the habit of careful observation, of accumulating facts, the reality and truth of which are tested by experiment, which sweeps away opinions based upon imperfect premises, which succeeds in leaving upon its pupil a profound regard for accuracy in all his work, must be a valuable addition to any course of education—an addition, for I should be sorry to urge that it was a complete substitute for any branch of knowledge except it be philosophy and metaphysics. How science has superseded philosophy was well told by George Henry Lewes when he wrote: "The method of verification, let us never forget, is the one grand characteristic distinguishing science from philosophy, modern inquiry from ancient inquiry. The proof is with us the great object of solicitude; we demand certainty, and, as the course of human evolution shows certainty to be attainable on no other method than the one followed by science, the condemnation of metaphysics is inevitable. Philosophy was the great initiator of science; it rescued the nobler part of man from the dominion of brutish apathy and helpless ignorance, nourished his mind with mighty impulses, exercised it in magnificent efforts, gave him the unslaked, unslakable thirst for knowledge which has dignified his life, and enabled him to multiply tenfold his existence and his happiness. Having done this, its part is played; our interest in it is purely historical."—Lancet.