The Most Important Discovery in Medical Science History?

One revolutionary theory that is of special importance in medicine is the germ theory of disease: the (at the time) shocking realization or assertion that many diseases (most significantly, those that were responsible for the highest mortality globally) had a microbiological origin--to put it more bluntly, those that were caused by tiny organisms, many of which could not be seen with the naked eye. Before this theory came into the scientific arena, many other theories floated around regarding the origin of diseases. The most notable sources/origins included:

• God's wrath--i.e., there was a spiritual explanation for all infirmities;
• The influence of the known factors of climate and season: heat, cold, moisture & dryness;
• The allegedly mysterious epidemic constitution of that given year's atmospheric characteristics;
• A harmful influence on the constitution of the atmosphere of a particular locality due to organic decomposition;
• Contagion by case to case transfer.

Other sources included a mysterious miasma that abounded everywhere and some elusive and strange things, such as bad luck and witchcraft. People went as far as blaming Jews and witches for their medical misfortune.

It was only when people like Anton Van Leeuwenhoek saw bacteria through a microscope and Edward Jenner used vaccines to cure and treat smallpox that people began to entertain the fact that small living things were in fact responsible for much of the world's sickness. In fact, according to Joshua Lederberg, "It was the germ theory--which is credited to Pasteur (a chemist by training) and Koch (ultimately a German professor of public health)--that set a new course for studying and contending with infectious disease." In the last part of the 19th century, these men molded the germ theory of disease from the historical empirical evidence available at the time and their own trend-setting research.

Whereas the new theory, the germ theory of disease, was squarely resting on hard-core science--i.e., statistics, epidemiology, biology, chemistry, and the new science of microbiology--the old theories rested on old wives tales, on superstition, on religion, and on less solid points of view. This new theory not only brought new facts to the surface--it also changed the way disease was viewed--thus prompting a revolutionary change of perspective.

As to what was responsible for the development or advancement of this theory, for the fact that the germ theory of disease overcame, replaced or enhanced previous theories, a number of things may be alluded to. For one thing, the world was gaining new understanding. As Andrew Sayer explains: "the world can only be understood in terms of available conceptual resources, but the latter do not determine the structure of the world itself. And despite our entrapment within our conceptual systems, it is still possible to differentiate between more and less practically-adequate beliefs about the material world."

New realms of thought were coming into fruition through such eras as the Scientific Revolution and the Reformation. Ideas that were once not allowed or immediately challenged all of a sudden gained respect, acceptance or, in some cases, tolerance. The thing that most pushed through this new theory, though, was the hard-core evidence that was eventually presented. Bit by bit, by a number of scientists, a case was made for this new way of looking at disease etiology . . . Eventually, the new perspective was absorbed.

One of the key lessons to learn from this historical achievement, though, is that this happened neither easily nor as quickly as one might have expected. In fact, there was much opposition to the new theory. Rudolf Virchow, a German pathologist, for example, rejected the notion based on the fact that not everyone exposed to these germs became sick--a concept referred to as the phenomenon of differential resistance.

This new theory, it was feared, might also give more motivation for the government to get involved in healthcare. Ironically, public health had always been viewed as a potential intrusion into the very private art/business of medicine. In this arena, physicians were in charge and any intrusion by the government was seen as blatant potential interference. The idea that germs were responsible for contagious/infectious diseases, though, threatened to break that control almost solely in the hands of physicians (in the 1800s).

Many older physicians, who had vested interest (in terms of intellectual capital) in the old ways, saw the germ theory of disease as an infringement on their power and control; consequently, they fought tooth and nail to preserve the wisdom already in place. A famous textbook (Creighton's 2-volume History of Epidemics in Britain), for example, fearlessly proclaimed that epidemics arose from the "poisonous substances" in the soil as late as 1894.

As to how professionals and scholars reacted to the new theoretical shift at the time, some were very happy and some were not so happy. The "old guard" (those who wanted to hang on to tradition and the old ways) viewed the notion that germs were responsible for disease very skeptically. Obstetricians, for example, had a hard time believing that their not washing their hands between patients was responsible for the high rates of deaths for new mothers, and surgeons were equally recalcitrant to admit that germs were killing as many patients (if not more) than the very diseases that prompted the surgery.

Conclusion

Lest one think that these views were only prevalent in the old days, Randolph M. Nesse reminds us that "Many people, including some physicians and scientists, still believe the outdated theory that pathogens necessarily become benign after long association with hosts. Superficially, this makes sense. An organism that kills rapidly may never get to a new host, so natural selection would seem to favor lower virulence. Syphilis, for instance, was a highly virulent disease when it first arrived in Europe, but as the centuries passed it became steadily more mild. The virulence of a pathogen is, however, a life history trait that can increase as well as decrease, depending on which option is more advantageous to its genes."

Although the germ theory of disease was eventually accepted, it had to overcome many hurdles, including the silly obstinacy of so-called experts who just didn't want to admit that they had always espoused false or incorrect concepts. As we gaze at the other avenues of discovery that still await us, can we be as stubborn and narrow-minded as those people who for so long fought against the theory of disease, in spite of knowing it was accurate?

While we may be thankful for theories such as these, we must be equally thankful for the lessons we can learn from its being proposed and, eventually, accepted. What other discoveries or assertions are some people making out there which the medical establishment, out of sheer obstinacy or because of fear of losing some benefit derived from the present agenda, is presently refusing to accept, espouse or even investigate?

For example, are there alternative treatments for cancer which have been rejected for reasons other than good science? Are the people presently in charge of cancer treatment too obstinate to consider any other options--especially if such may not be as profitable as what they presently peddle?

What about vaccines? Are they really as safe and effective as the medical establishment absolutely believes? Or is it possible that the powers that be are as wrong about their assertion as all those doctors who for decades fought against the new wisdom of the germ theory of disease?

Finally, what about all those scientists and doctors who are on record as having testified for decades that there was no connection between cigarette smoke and cancer? The fact they were experts and sure about their views did not change the fact that they were ultimately "dead" wrong.

In science, maybe what we need is a little more humility. We need to keep our minds and our eyes open for new possibilities. We need to approach every assertion as if there is merit to be found. A lack of merit must be confirmed through legitimate, objective scientific enquiry. Otherwise, we run the risk of being as obstinate, ignorant and unjustified as all those scientists who questioned and fought against the germ theory of disease.

Clearly, it should not have taken so long for those people to be proven wrong. If only they had been more professional, more open-minded and more committed to scientific truth (rather than to profit, power and conceit), science would have moved much faster, thereby improving not only medicine, but quality of life for many people.

Copyright, 2015. Fred Fletcher. All rights reserved.

References

Johnson, S. Ryan. 1994. Food for Thought. Historical Methods, 27(3).

Lederberg, Joshua. 2000. Infectious History. Science, 288.

Nesse, Randolph M. 1998. Evolution and the origins of disease. Scientific American, 279(5).

Reverby, Anne. 1972. The history of contagious disease. American Journal of Public Health, 62(8).

Sayer, Andrew. 1992. Method in social science: a realistic approach. New York: Routledge.