Theobald Smith's presidential address to the 'Society of American Bacteriologists'

Fifth annual meeting of the Society of American Bacteriologists, Philadelphia, PA, 29-30 December, 1903
The address was published in ASM News, 47:231-235, 1981, reproduced herein with permission from ASM

Theobald Smith

The privilege of welcoming you and of presiding over our deliberations falls upon me during this year’s session.  In anticipating the pleasure of meeting you as presiding officer, I had endeavored to keep that function well in the background by not preparing a formal address, believing that this was the custom and that it would leave all the time for the program of announced papers.  I learnt too late that some of our most active members thought the custom of an annual introductory address was a desirable thing to be introduced and cultivated from year to year.  I quite share this view and earnestly advise my successor to begin to think early and seriously upon the matter.

To speak extempore or even after mature thought without carefully prepared manuscript upon topics of science today is impossible.  Science does not cling tenaciously to one aspect of a subject, take sides, and exhort and entreat its votaries to share its views, but its true essence consists in presenting as many aspects, as many conflicting theories which have any standing as possible.  Science can never sermonize, but it can and must raise doubts and lead to further searching enquiries.

The few thoughts I wish to express are more or less extempore.  They have not been as fully matured nor written down with that care which is demanded on occasions like this, and they are presented with some hesitation as the hurried efforts of the past few days.  I am not informed that there exists another bacteriological society of any standing like our one, either here or abroad, though bacteriological topics occupy much of the time of associations dealing with medicine and surgery, hygiene and pathology.  The reason for this is probably the fact that although in Europe specialization has gone much further in scientific pursuits than with us, the outlet of men’s thoughts and work is through fewer and much older associations where, by the creation of sections, specialization is allowed a certain scope.  With us, development has been freer.  Bacteriology has been growing in various directions and has broken away from its intimate association with medicine and hygiene.

To be successful, however, bacteriology must ally itself with some other branch of science.  Bacteria are not an end in themselves, but knowledge concerning them contributes to the solution of higher problems.  This is distinctly the tone pervading all scientific enquiry today.

Whatever may be said of the doctrine of the ideal university where nothing useful is to be taught, it has a hollow and sepulchral ring when it is sounded today.  Science is privileged to exist only in so far as it contributes to the advancement of the human race, material, intellectual, social.  But since every conceivable subject now taught and cultivated can easily present a plea, either true or specious, of its essential value to mankind in some near or remote degree, none need fear for an early withdrawal of its charter.

Turning to bacteriology we find it above all studies endeavoring to fulfill a practical mission.  It is being cultivated by all departments of curative and preventive medicine and it has exerted on them an overshadowing influence.  It has an important place in plant pathology, in various departments of agriculture, and the fermentation industries.

The development of bacteriology itself is dependent largely upon the various departments of chemistry, for what bacteria do in the aggregate is what all are clamoring to know, and their activity must be ultimately defined in the language of chemistry.  Upon all the branches of science with which it has been linked, bacteriology has exercised a most stimulating influence.  It has revealed a new world of intense vital activity whose behavior must be taken into account in many biological phenomena.

The growth of bacteriology is most concisely expressed in its teaching literature.  Late in 1883, when I began work in medical bacteriology, only a few small textbooks were on hand.  Later, a larger edition of Flügge’s textbook appeared.  After a considerable period the same textbook appeared in two large volumes in 1896, but no longer written by one man.  Today, the much larger work of Kolle and Wasserman, to consist of perhaps three very large volumes and written by many hands, marks the rapid growth of the subject.  In France, Duclaux in his large publications has made an effort to include branches of science other than those of medicine in which bacteriology has a prominent place.

The rapid accumulation of facts concerning the protozoa in their relation to diseases of tropical and subtropical climates is building up a branch of medicine to which bacteriologists have freely contributed.  Much in the life history and the pathogenic activities of protozoa runs parallel to those of the bacteria, and the two fields are at present best taken care of together.

When it comes to the teaching of bacteriology, the question of the formation of groups of related subjects under one head and the assimilation of bacteriology with some major study is a difficult one to approach.  At present, it is solved by local considerations and temporary expedients rather than according to a well-defined principle.  It seems to me that the study of parasites such as the bacteria and the protozoa must go with that of the hosts whom they attack.  Hence in human and animal pathology and preventive medicine, medical bacteriology finds its best guides.  In agriculture, the plant and the fermentation industries, the best interests of the subjects demand the subordination of bacteriology to them.

Though this arrangement leaves bacteriology apparently without an independent prop, I think it is nevertheless entitled to one.  There are many aspects of the study of bacteria which would not be dealt with in any subordinated position, and in our largest universities the study of bacteria as such should continue to be cultivated in order that the development of our knowledge of them may continue symmetrical and broad.  Such a position demands much self-denial, for the professor should attack not the striking, popular problems but the neglected ones, those which the medical, the sanitary, and the industrial bacteriologist frequently are compelled to pass by.  Turning to the dominant field in bacteriology, that cultivated by medical science from its broadest as well as most specialized points of view, we find the problems changing from year to year in accordance with a clearer insight into the activities of pathogenic species.

In the earlier years, the discovery of a bacterium as the cause of an infectious disease was quite an event.  Today, such announcement does not cause much stir, for we know the great gap which exists between the recognition of a microbe and an intimate knowledge of its relation to the disease processes with which it is associated.  The discovery of the microbe is but the first gun fired in a long and exhaustive warfare.

Again the study of those processes and agents which destroy bacteria -the study of disinfection- was from the first the most diligently cultivated branch of bacteriology.  But beyond the immediate object sought, it remained a barren study.  To kill microbes did not bring us any nearer to their mode of warfare.  To learn that many of them may carry on a peaceful existence in healthy individuals and so escape attention and attack, and from them spread disease among the highly susceptible, clearly showed that disinfection cannot accomplish everything and that bacteria must be approached in a more conciliatory manner and set at work upon living tissues.  As a result of such new lines of research, we today are inclined to seek the true ius morbi not precisely in the microbe nor in the host, but in that delicate equilibrium between the two which is maintained in various intricate ways.  Of these, the reciprocal production of antibodies is the most striking phenomenon of the hour.  In other words the pivotal point of bacteriological studies has moved away from the bacteria and the host to a point midway between them.  Whatever influences either host or microbe changes this delicate equilibrium, and it remains for medical science to determine more accurately the laws governing it.  At this point I cannot refrain from alluding to the great influence exerted by the study of infectious diseases of the lower animals upon bacteriology.  The earliest definite observation upon bacteria as disease producers was made upon anthrax in sheep.  Pasteur and Koch have done their best work upon infectious diseases of man, which are either easily communicated to animals or shared by them.  But even these illustrious examples have not been sufficient to relieve medical bacteriology of a certain rigidity imparted to it by the hosts of medical workers who have dealt only with human infections.

This delicate equilibrium between host and parasite which I touched upon a few moments ago is different in every host species.  Only be a comparative study of these differences can we hope to arrive at any satisfactory generalizations and rearrange and organize the overwhelming mass of data which has been rapidly accumulating.  As long as the stupid distinction between human and animal pathology is maintained, a distinction which has its roots buried in the ignorance of the past, progress will be slow.

We are indebted chiefly to bacteriology for having greatly reduced this barrier between human and animal pathology, a barrier of which no trace has existed for some time in physiology.  The physiologist has in fact fallen much lower than the pathologist.  He did not stop until he came to the frog.  The pathologist himself is even now getting options on the frog, and in the not distant future no animal from the anthropoid apes down will be sufficiently skilled in mimicking health to escape his searching methods.

Besides uniting human and animal pathology, bacteriology has been largely instrumental in awakening public interest in the doings of medical science and in uniting pathology and biology.  Pathology is after all merely a branch of biology, or the science of life, and the kinship is being recognized more and more.  Without some appreciation of pathological data, biology loses much of its savor, is in fact only a half-study.  The boundary between normal and abnormal states is vague and shifting, and no one can tell where one begins and the other ends.

It may be claimed that pathology can never be very popular as a branch of biology because the morbid sensitiveness of intellectual life is apt to shun thoughts of diseased states.  To this it may be answered that geology might as well refuse to consider volcanoes and earthquakes in its teaching, because these phenomena are destructive to man.

To bacteriology, I repeat, belongs the credit of having enlisted the interest of the world at large in the study of disease.  As long as pathology was absorbed chiefly in the postmortem room, there was little that was attractive, but the unfolding of the microbic causes of disease and the study of bacteria in different departments of science have brought pathology out of the dead house into the light and made of it a constructive, hopeful study.

If we attempt to analyze the movement of applied science and of applied biology more particularly at the present time, as it is molded and influenced by public opinion, we find the secret of much effort to be the desire to so understand the processes of nature that we may interrupt them at will and turn aside their energy to suit our purposes.  A cultivation of science for its own sake is not a marked characteristic of our age.  Its secrets are exploited chiefly for useful ends, either selfishly or unselfishly.  Leaving aside the moral character of the motive which prompts scientific investigation, we may be certain of one thing, that the secrets of nature will not be discovered by pseudoscientific, slovenly, or overhasty endeavor.  Sofar the dignity of our vocation will be preserved. Yet on all hands we are pressed for the solution of problems entering into the daily life of society and the state, for the successful attack of which we are far from ready.  They may be provisionally answered, but the machinery we thereby set in motion may do much damage.

The intimate relation between bacteria and the life and health of human beings makes the dictum of the bacteriologist of very great significance.  Extensive sanitary machinery follows in the wake of his investigations.  The savings of communities are spent in large public works approved and inaugurated by him.  The daily life of each individual molds itself to suit the opinions of sanitarians.  Our statute books are full of health laws growing out of his work.  How important therefore for him to move slowly, to avoid the temptations of gain, the acrimony and heat of the advocate.  How important to recognize the fact that certain sanitary improvements may be bought too dearly!  We have fastened upon our communities today the teeth of capital and labor trusts battening upon top-heavy plumbing regulations dating from the good, old sewer gas times.  Only a few years ago in Massachusetts entire carcasses of cattle in excellent condition for food were condemned by law and converted into fertilizers because of barely visible tubercles in a mediastinal lymph node!  Other illustrations might be cited of the dangers besetting science in being petrified by law makers.  What is needed above all things is deliberation in transmuting the results of research into the law of the land, since it is always better to leave the world as it is unless we are absolutely certain that our new ideas are going to improve it.

Looking at bacteriology from these and other points of view, we can hardly doubt the justification of a society of bacteriologists, even though its members represent a variety of different callings.  If the future should show a gradual weeding out of men engaged in all but one calling, if the representatives of different specialties should gradually lose their interest in the society and leave it either to the medical bacteriologists or to the sanitarians, or to the agriculturists alone, then I believe the time shall have come for its amalgamation with the larger organizations devoted to these subjects.  In the meantime we shall watch with much interest the career of this society and hope that the idea underlying its organization may prove a sound and fruitful one.

The first fifty-two presidents of the 'Society of American Bacteriologists' (later American Society for Microbiology)
Presidents Society of American Bacteriologists
From Directory and Constitution, Society of American Bacteriologists, 1952

Microbe Hunters, by Paul de Kruif