Science, Reason, Ethics, and Modern Medicine Part 1: Tu Quoque and History

Several weeks ago I argued here that a physician’s primary ethical obligation is to science and truth. In retrospect I probably should have put it a slightly different way: a physician’s primary ethical obligation is the same as everyone else’s. It is to honesty and integrity. For physicians, however, that means being true to real medical knowledge, among other things, and real medical knowledge comes from science. That is what this and the next several posts will be about.*

First, a little Tu Quoque

After reading some of the comments that followed my posting of two weeks ago, I reluctantly thought to add a few words about the medical profession’s view of physicians selling drugs. It felt tiresome to have to address the issue, because it is beside the point. The series was about “naturopathic medicine,” not about modern medicine. If readers who understand the point will excuse the interruption, I’ll quickly attempt to explain why by posing two extreme possibilities: If MDs are entirely innocent of the relevant breach of ethics, what would that have to do with naturopaths selling drugs? But if MDs are entirely guilty, two wrongs don’t make a right—demonstrating the same irrelevancy.

That is why the “you should talk” sneer is known, in debate, as the tu quoque (“you too”) fallacy. It’s funny how parents seem to recognize it when faced with children who, in seeking permission to engage in dubious activities, invoke the parents’ own sordid histories or the equally irrelevant, alleged prerogatives of other people’s children. Yet the same parents appear to forget it in other contexts.

I was also weary and wary of those who would draw me into a strawman debate pitting the medical profession against any group of sectarian health advocates. I have only a small sense of “solidarity” with the group of people who have MD degrees, and even less so with organized medicine. My first allegiance, as I’ve explained elsewhere, is to science and reason. Those modes of inquiry, together with their obvious bearing on the integrity of all claims about nature, are the bases for my objections to naturopathy and to pseudoscience in general. The medical profession per se is related but not central to the issue. While thinking about these things, it dawned on me that a discussion of why that is might be useful.

Another tu quoque argument popular among advocates of implausible medical claims is that “medicine doesn’t know everything,” i.e., that there are still diseases left unsolved that people suffer and die from, which somehow impugns modern medicine and the basis for its best practices (science). That said, advocates want to invoke “alternative” medicine, which would be an obvious non-sequitur even if such impugning were justified, which it is not. It is the assertion that science-based medicine can’t deliver—demonstrating an extreme ahistoricity on the part of its advocates—that is the topic of this post. I’ll get to the issue of selling drugs another time.

An Essential, Very Short History of Science-Based Medicine

Economics aside, science and reason, including rational evaluations of empirical observations, have been the bases for every purposeful advance in our species’ age-old struggle with diseases, trauma, specific malnutritional states, anatomic and genetic anomalies, problems of aging, and every other problem that comes under the heading “medicine and public health.” Even before the advent of biology or medical science, empirical observations yielded occasional, useful discoveries, such as cinchona bark for marsh fever, innoculations of pus from cowpox blisters to prevent smallpox, limes for sailors to prevent or cure scurvy, food preservation and preparation by salting, cooking, smoking, cooling, or fermentation, and more. There were, undoubtedly, at least a few such advances in every place where humans lived for any length of time. The adjective “purposeful” is intended to exclude happy accidents of biology and the environment: reason did not create cinchona or vaccinia or salt or fermentation or water or fire, but it certainly led us to discover and use them.

Here are a few notions that have had no bearing, whatsoever, on advances in medicine and public health, and never will: vitalism, mysticism, demonology, voodoo, homeopathy and all other forms of sympathetic magic, qi, meridians, the five phases, the four humors, the five pranas, mysterious “energies,” astrology, psi, chiropractic “subluxations,” “craniosacral rhythms,” fanciful homunculi on the iris or the external ear or the sole of the foot, faith healing, other forms of magical thinking, and many more. To the extent that real advances may occasionally have occurred in contexts of pre-scientific practices, they were due to empirical observations, not to the “theories” themselves. More commonly, particularly in recent decades, such practices and beliefs have merely obstructed useful approaches.

Obviously we haven’t solved every medical problem yet. We’ve barely begun, in the greater scheme of things, yet we’re making progress at breakneck speed. Our species, homo sapiens sapiens, is about 200,000 years old. Our brain, the organ that allows us to reason and thus to solve medical problems, has been in its biologically modern state for at least 40,000 of those years (I remember reading somewhere), and possibly for the entire 200,000. Yet we have begun to solve medical problems in earnest only in the past 150.

A smattering of scientific bases for medicine, including systematic attempts to describe and catalog diseases, existed in antiquity. The investigations and habits that eventually culminated in science-based medicine, however, seem to have begun about 1000 years ago. Evidence for this is a rational treatise on testing medical substances, the first post-mortem dissections, by Ibn Zuhr, early investigations into physiology, and probably more. I am not a historian of medicine and I’ve not read the primary sources for the linked pages in Wikipedia; they strike me as exaggerated (how, hundreds of years before the invention of the microscope and the discovery of micro-organisms, could “bodily secretions…contaminated by ‘foul foreign earthly bodies’ ” be construed as “bacteriology and microbiology“?). Nevertheless, the assertions linked above appear to be justified by actual documents.

In the 16th century Vesalius published the first accurate human anatomy. Within a century William Harvey had described the circulation of blood, and shortly after that Antonie van Leeuwenhoek discovered micro-organisms. All the while, investigations of diseases became increasingly rigorous and reproducible because of post-mortem examinations (autopsies), so that “clinico-pathologic correlations” were possible. The contemporary scientific revolution, in particular the rise of empiricism, led to other discoveries that set the stage for investigations in the 19th century that heralded the arrival of modern, science-based medicine.

These included the discovery of oxidation and the demonstration that living organisms obtain their energy by that mechanism, in accord with the same thermodynamic obligations that apply to combustion and other chemical reactions, microscopic pathology, cell theory, biochemistry, experimental physiology and experimental medicine, including early insights into the existence and functions of hormones, water and electrolytes in tissues, the excretory role of the kidneys, the nervous system, digestion, respiration, including the oxygen transport function of hemoglobin, the heart’s pumping function, pharmacology, statistics, inhalational anesthesia, local and regional anesthesia, the germ theory, immunology, modern surgery, epidemiology and rational public health measures, X-rays, and more. Among other effects, these fields convincingly refuted such beliefs and practices as vitalism, spontaneous generation, miasmas, the humoral theory of disease, homeopathy and other forms of sympathetic magic, bloodletting, purging, scalding, and more.

Thus real science-based medicine has been around for less than two tenths of 1% of the time that our species has existed. In that short time it has solved most of the major plagues that had previously wreaked death and sorrow upon all humans since time immemorial, and that still do so in regions where, for political or economic reasons, science-based medicine has not become widely available. It has also solved many non-epidemic infectious diseases, all of the major nutritional deficiency states, has discovered almost all of the causes and most of the cures of anemia, has provided safe, effective, and painless surgical cures for common, previously deadly diseases such as acute appendicitis, infantile pyloric stenosis, acute cholecystitis, and acute diverticulitis, has solved the most common type of peptic ulcer disease, has drastically reduced the dangers of childbirth and infant and childhood mortality (previously the sources of the greatest sorrow and suffering that our species has endured), has devised marvelous treatments for severe trauma and burns that until very recently would have meant certain death or severe disability, has solved many of the congenital anomalies that also would have meant certain death or disability, has transformed the lives of patients with previously deadly diseases such as type I diabetes and AIDS, allowing them now to thrive for years, has made other common chronic diseases, such as gouty arthritis, rheumatoid arthritis, and inflammatory bowel disease much more bearable, has made significant advances in diseases such as coronary artery disease, strokes, and cancers, that have become more prevalent now that people live longer, and much, much more.

It’s astounding to consider the tiny sliver of time during which these changes have occurred. When I was a kid in the 1950s, there were plenty of people still living who could remember life before effective, rational medicine and public health. My great-grandfather had been born in 1853 into a family of 5 children, of whom 2 died in infancy. His mother died when he was 12. That was the norm for the mid-19th century in the United States. Widespread suffering, disability, and premature death have almost certainly been the norms for every population of humans throughout the entire history of our wretched existence, and are still the norms in parts of the world that remain too poor to have reaped the benefits of science-based medicine and public health.

Here is another way of considering how recently all of this has happened: if we assume that a generation of humans corresponds to about 20 years (probably too short here and now, but not for most of our existence), there have been about 10,000 generations so far. All of the breakthroughs mentioned above, and more, have occurred during the last 6-8. More recently, within the past 2-3 generations, the stage has been set for even more astonishing breakthroughs. Molecular biology and its applications to genetics, virology, immunology, and pharmacology, for example, inevitably lead to breakthroughs in the understanding and treatment of viral diseases, cancer, hemoglobinopathies such as sickle cell disease, and more.

An example of this is the history of our understanding of AIDS, which progressed from a new, terrible, rapidly terminal disease of unknown etiology, when it was first described in the early 1980s, to one explained in complex detail, with treatments so effective that the majority of patients receiving them could expect to feel well indefinitely, barely 15 years later. Come to think of it, within a period of a few years beginning in about 1980, at least 5 serious diseases—AIDS, Legionnaires disease, Toxic Shock Syndrome, Lyme disease, and peptic ulcer disease—were solved or mostly solved. The first three of those were entirely new and scary when they first presented themselves. Imagine what our ancestors would have thought. Imagine how they might have “treated” such diseases, merely a few generations ago.

And yet as recently as 10 years ago, AIDS was a favorite playground for quacks (still is, but now the same claims are mainly for “complementary” effects). Funny: that was also true for polio, cholera, yellow fever, and every other epidemic disease prior to its being solved by science-based medicine.†

Next week: more Bait and Switch.

†Young JH. American Health Quackery. Princeton: Princeton University Press, 1992


* The Science, Reason, Ethics, and Modern Medicine series:

Science, Reason, Ethics, and Modern Medicine Part 1: Tu Quoque and History

Science, Reason, Ethics, and Modern Medicine, Part 2: the Tortured Logic of David Katz

Science, Reason, Ethics, and Modern Medicine, Part 3: Implausible Claims and Formal Ethics Statements

Science, Reason, Ethics, and Modern Medicine, Part 4: is “CAM” the only Alternative? And: the Physician as Expert Consultant

Science, Reason, Ethics, and Modern Medicine, Part 5: Penultimate Words

Posted in: Medical Ethics, Science and Medicine

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