EVERY ONE A DEBTOR TO HIS PROFESSION. 81

PART III.

THE CLAIMS OP MEDICAL SCIENCE UPON MEDICAL MEN.

And, finally, the question occurs, what are the claims of our science upon us as medical men?

This question would be answered very differently by different members of our profession, since they cherish very different kinds of attachment to science, as is expressed by a German poet:

"To some she is a goddess great;
To some a milch cow of the field:
Their business still to calculate
The butter she will yield."

But our science has claims upon us all alike ; and I may indicate the manner in which we should respond to them, in the words of the author of the "Novum Organum :" "I hold every man a debtor to his profession; from the which, as men do seek and receive countenance and profit, so ought they of duty to endeavor themselves to be a help and an ornament thereto." It is often repeated that ours is a noble science ; then we can become an "ornament thereto" only so far as we are individually scientific and noble men. But we maybe a "help" to our science in two ways; 1, by our own labors, and 2 by encouraging the labors of others.

How improve our science by our own labors.

I. There are three principal methods of improving our science by our own labors : 1, by ascertaining and correcting existing errors ; 2, by collecting and arranging established facts in a scientific form, in monographs, treatises, etc.; and 3, by making new additions to it, or actual discoveries.

1. In order to ascertain and to correct existing errors, it is necessary to question and reexamine all ancient opinions. We have seen that men often continue " acquiescent in errors so baseless, that they vanish immediately they are challenged." We must then challenge old opinions. I do not inculcate skepticism ; that is usually the offspring of ignorance. I bespeak that rational and temperate doubt, which an acquaintance with the history and development of all science cannot fail to cherish. "He who seeks for truth," says Descartes, "must, once in his life, doubt of all he believes." I would encourage the habit of scrutinizing the doctrines and opinions of others; and, above all, of forming our own opinions, upon data which we possess in common with them ; in a word, of being "Nullius addictus jurare in verba magistri." The habit of thinking for ourselves may seem to imply that of observing for ourselves; for we have seen that in the formation of science, sense and reason—observation and deduction—have a mutual need of each other. But we are to remember the difficulty of observing correctly ; and that while "the knowledge of the senses is the best of know

INDEPENDENT THINKERS ARE RARE. 83

ledge, delusions of the senses are the worst of delusions." * Each, therefore, should ask himself if he has the qualifications for a good observer, and the leisure for making observations ; and, if not, he may rely on others for facts, and restrict himself to the interpretation of them, as we have seen was the case with Harvey and Newton. In respect to independence of opinions, it will, however, always be true of the vast majority of even educated minds, as in the time of the author of the "Praise of Knowledge." "They learn nothing at the universities but to believe. They are like a burdened ship, they never move, but by the wind of other men's breath, and have no oars of their own to steer withal!" We wonder at the poverty and servility of the human mind in the middle ages. But the number is comparatively very small in every age, of those who, thinking and reasoning independently, advance . their science, and compel the rest to follow, though with lagging and unequal steps. Without the independent thought of Vesalius, Caesalpinus, and Harvey, the circulation of the blood might have remained undiscovered to the present time. There are now many important subjects in the various departments of our science which require to *be investigated entirely de novo. Digestion is one of them, as we have seen. And none should be deterred by their obscurity, from the expression of their well-formed opinions. Every man is obscure in science till he makes himself otherwise; and young men have ever done more for science than those far advanced. Vesalius published his great work on anatomy when twentynine years of age ; Andral published his on Pathological Anatomy when but twenty-seven years of age; and Bichat had completed all his immense labor at the early age of thirty years.

2. After reexamination of the received facts and principles of our science, and the rejection of such as are found to be false or untenable, we may contribute much to its future advancement by others, or by ourselves, by collecting the established facts and principles, and arranging them in a systematic order in the form of a compendium, a monograph, or a treatise on the particular subject or department concerned. Thus the labor of acquiring that department, up to the present time, is vastly abridged ; and the student, and even the practitioner who has but little leisure, can gain that amount of knowledge which is indispensable, in no other way. The compendium, or treatise, however, affords only a panoramic view, as it were, of the particular department of science; the details must be subsequently sought in the monographs on the particular topics it includes.

3. To those who would advance our science by actual discoveries, whether of facts or principles, the following considerations are of importance.

Fint. Those who would become discoverers, should evidently commence their preparation by accurately acquiring all that is already known in the department they propose to advance. Many an individual who prides himself upon his talents for original investigation, has found, after arriving with much labor at

a particular result, that another had already done, and perhaps much better, precisely what he had accomplished. A vast amount of intellectual power is absolutely thrown away, from this kind of ignorance. When we have acquired all that others have achieved, or have learned where, why, and in what way, others have failed, then, and only then, may we exert our own powers with the best prospect of success.

Secondly. If we would make additions to our science, we should have a definite idea of the precise object we wish to accomplish. Thus alone can we propose a definite question to the mind ; which is the only way to achieve a definite result. For "rightly to state a problem, is no inconsiderable step towards its solution." .. str j

Discoveries are of two distinct classes.

Thirdly. The future discoverer in our science must remember at the outset, that in respect to the methods for achieving them, discoveries may be arranged in two classes: the observational and the rational. The first are discoveries of facts alone, and are made by the use of the senses merely—by observation; the second are discoveries of principles or laws, and are made by the use of the reason, by deduction, and are afterwards verified by facts. In the first, the discoverer merely sees; in the second, he foresees. The discovery of a continent, an island, a comet, a new chemical element or compound, of a muscle, or of any anatomical or histological element, are instances of the first class of discoveries ; those of