Inductive & Deductive Paths
The Human Condition
Humans are the great dream weavers who, fiber by fiber and thread by thread, fashion the whole cloth of reality. We have named these realities “culture.” Cultures are persistent in part because we do not see ourselves as creators. We fail to note our true creative role because realities emerge across many generations, tend to be inherited by our children (thus, taken for granted by them), and protected from heretics by social control. Reality is hard to doubt.
Instead of taking creative credit, we weave Weavers (think of the thousands of gods the thousands of human cultures have created and believed in with all our hearts) and other mysterious and powerful explanations into the fabric of our realities. I call reality a practical illusion: what works for survival is practical; how existence and survival are understood, that is our illusion (and but one among the world’s many cultures).
How much in science is (potentially) practical; how much is illusion? The same two questions must be asked about the profession of medicine.
Survival of the Fictitious
Reality creation is communal inductive reasoning. It first became formalized as individual reasoning under the influences of Socrates and Plato. In the universities that developed some 1500 years later, this form of logic (the Dialectic) was incorporated in the Liberal Arts Trivium of Grammar, Rhetoric and Logic.
Medical knowledge spread from monastic schools to secular universities, became more complete as ancient texts were translated into Latin, and was increasingly systematized over the first several hundred years of the 11th century. Separate medical degrees began to be offered in the Little Art (“Articella”) of Medicine. Practical medical knowledge was taught (some accurate, some most definitely not) in medical curricula, of course. However, at the heart of medical education were the metaphysical humoral theory of disease and the logical reasoning of Socratic Platonism. The humoral theory was based on nothing factual; it remained dominant for over 900 years, until the 19th century, but persisted into the early 20th century. Socratic Platonism survives to the present as the dominant form of medical reasoning.
A New Game in Town
Scientific reasoning represents a rebellion against the inductive reasoning of common sense. The scientific process is the antithesis of medical logic. To attain the scientific perspective required centuries of turmoil, doubt, deconstructing old thought-ways and the building of a new reality. We distinguish this general timeframe with the names The Renaissance and The Enlightenment, thus spanning the fourteen hundreds through the seventeen hundreds. And of course, the sciences continue their revolutionary construction of new realities.
Many specific changes had to converge to forge science from extant traditional culture. For example:
(1) The natural realm had to be separated from the supernatural because science cannot explore, control, measure or predict supernatural conditions. Science must presume that things-cause-things (methodological atheism) without supernatural influence (e.g., God’s will).
(2) Scientific knowledge had to remove from itself any metaphysical assumptions (e.g., the ether, phlogiston theory, spontaneous generation, miasma and humoral theories of disease, animist notions of chemical bonding and gravity).
(3) Science had to realize that bias informs most of what we in everyday life take to be true.
(a) Each society’s culture prefers one set of beliefs over those of any other culture. There are many cultures, each populated by people believing they know Truth.
(b) Our language, which points back to our reality, adds its own syntactical and semantic biases as it helps us to form our thoughts.
(c) Our particular biographical experiences provide us with the biased perspective of a lifetime.
(4) Science also had to extricate itself from common sense and its underlying logic of reality creation. Natural philosophy devised new rules for evidence, the alternative of deductive logic, and experimental methods of observation. All of these innovations reduced or removed the opportunity for bias.
Science uses its theories, mathematical language, controlled observation, replication and publication to wash commonsense biases from its findings. The involved scientific process outlined in the preceding sentence is focused and constrained by the necessity to produce the ‘deductive moment’. That moment confirms or fails to confirm some hypothesis with a high degree of certainty. The scientific revolution was rethinking the nature of reality.
[Sir Francis Bacon, sometimes called The Father of Science, Novum Organum, 1620: Bacon created a still relevant catalog of four biases to our reasoning. These are now called “Bacon’s Idols”. They are the Idols of the Tribe, Cave, Marketplace and Theater. Above, (3) a-c represent the Idols of the Theater, Marketplace and Cave, respectively.]
The Doctor Has No Clothes
Consider this: Medicine has always been a treatment profession whose method of reasoning could not disprove humoral theory, nor challenge the inefficacy of treatments based on it. Medicine has a very old, non-scientific trait of wishing something were true and insisting on it. Certainly, change did come in the medical understanding of disease. Science applied itself to medicine and forced the demise of humoral theory and, one by one, its associated treatments. Medicine’s inductive, clinical reasoning remained unchanged.
Medicine remains a treatment profession and has not evolved into a science. As a treatment profession needing trust and authority to survive financially, medicine took on the vestments and props of science, acceded to germ theory, kept its esoteric vocabulary with borrowed scientific terms, and declared, without basis, that it was “scientific medicine.”
Nonetheless, medicine does not train is physicians to be scientists nor does it encourage statistical numeracy (the language of biomedical research). Physicians are not taught to think like scientists or to appraise professional or scientific publications.
Medicine does still train its physicians with thousands of hours of practice in an ancient inductive logic. The arduous training process depends on seeing-hearing-using the inductive frameworks of clinical appraisal with such massive repetition that it is mind-altering, internalized and habitual. Arriving at a definite conclusion by inductive reasoning is illusory; medical thinking contains no ‘deductive moment’ when high certainty is reached. Error, thus, is part of the normal practice of medicine.
As a culture, medicine is indifferent to careful observation and testing. Unlike science, medical practice contains no positive, self-corrective mechanisms or means for risk assessment. Even trial and error brings no necessary accounting of error. The promise of medicine is to cure disease and reduce human suffering related to states of ill-health. Yet we are a society plagued by chronic diseases from childhood to death — despite being the most prescription-medicated people on our planet.
The Illusion: Medicine is Not What It Seems
A question was asked at the beginning of this essay about the balance of the practical and the illusory within medicine. To answer that question, I leave you with this:
When many forms of iatrogenic death are brought together from scattered pieces of research, and extrapolated to the population, unnecessary medical intervention (a form of error or abuse) and “medical error” become the leading cause of death in the U.S.
Of about 2500 treatments researched for efficacy, an alarmingly small percent of medical protocols have been found to have a positive or possibly positive effect (36%); forty-six percent (46%) have not demonstrated benefit or harm, and about 18% are in a very ambiguous state of proof (a tradeoff between benefit and harm, as likely to be ineffective or harmful, or unlikely to be beneficial). The literature on medical treatment has settled on the shockingly low range of 20% to 25% effectiveness.
“We don’t have the evidence that treatments work, and we are not investing very much in getting the evidence.” –Dr. Stephen C. Schoenbaum, The Commonwealth Fund
“The big myth about medicine is that people know what works. In fact, they do things for which there is no evidence. There is a tendency for doctors to exaggerate the benefits of what they do because they want to help.
I think conveying uncertainty is important. We need to say when we just don’t know. ” –Luisa Dillner, editor, BMJ Best Treatments
“In many instances, we simply don’t know what we are doing.” –David Eddy, physician-mathematician, father of evidence based medicine
“…[T]he scientific base of medicine is weak and … it would be better for everybody if that fact were more widely recognized.” — Richard Smith, Editor, British Medical Journal (BMJ)
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Medscape, “More Americans Take Prescription Medication”, May 3, 2005,
http://www.medscape.com/viewarticle/500164 (accessed 5/9/2015).
Kaiser Family Foundation, “Prescription Drug Trends – May 2010 Update”, June 2010.
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Gary Null, et al. Death by Medicine, Axios Press, 2011. And cf. Institute of Medicine To Err is Human, National Academy Press, 2000.
BMJ http://clinicalevidence.com/ceweb/about/knowledge/jsp, accessed 5/6/2007, no longer accessible. See http://www.huffingtonpost.com/dana-ullman/how-scientific-is-modern_b_543158.html for cross citation.