What Doctors Don’t Know

To the Editors:

I was, of course, pleased that Richard Horton in his review of my book The Rise and Fall of Modern Medicine [NYR, November 2, 2000] should share my skepticism about the claims of the two main pillars of current medical research—the New Genetics and the Social Theory. But the reason why they have proved disappointing needs to be emphasized. Put simply, despite the prodigious advances of the last fifty years, there remains a vast lacuna of ignorance at the heart of the medical enterprise—we simply do not know the cause of most of the illnesses to be found in the medical textbook. There must be a biological explanation as to why the nerves in those with multiple sclerosis should lose their protective fatty sheath or why the joints of those with rheumatoid arthritis should become painful or inflamed or why characteristic types of brain cell loss give rise to the symptoms of Parkinson’s, but we simply do not know what it is. This profound ignorance of the biological cause of disease is, to change the metaphor, the brick wall or ceiling which current medical research seems to be unable to breach. The problem, of course, is that people demand explanations and doctors are perhaps too happy to provide them. Hence the public is regaled with a seemingly endless litany of pseudo causes that would attribute such illnesses to an “unhealthy lifestyle” (the Social Theory) or “faulty genes” (the New Genetics).

James Le Fanu
London, England

Richard Horton replies:

In the prologue to his assault on modern medicine, James Le Fanu points out that big discoveries in twentieth-century clinical science owed more to blind luck than rational inquiry. He goes on to challenge two of the most rational, but not necessarily sensible, enthusiasms of latter-day medical scientists—genetics and epidemiology. But in his letter to The New York Review, Le Fanu has turned his arguments inside out and back to front. Sensible, but not necessarily rational.

Le Fanu now claims that the only limitation to healthful nirvana is our “profound ignorance of the biological cause of disease.” Yet in his book, and using the same “brick wall” metaphor, he rejects efforts “to undermine the wall by illuminating the workings of the human organism at its most fundamental level with the promise that at some indefinable point in the future the brick wall would come tumbling down, leaving a long straight road to health and happiness for all.” Instead, he puts his faith in “knowledge based on practical experience.” These two positions—for and against efforts to discover underlying mechanisms of disease—are incommensurable.

Neither genetics nor epidemiology will provide definitive methods to solve questions about the origins, prevention, and treatment of disease. But at least they offer useful means to evaluate cause and risk, two concepts without which Western medicine would be paralyzed. True, the Social Theory and the New Genetics ultimately fail in their purpose. Neither is able to appreciate the integrity of human pathology. As the physician-philosopher Georges Canguilhem put it, disease is “an effort on the part of nature to effect a new equilibrium in man.” Disease has its own order.

Contrary to orthodox medical teaching, health is not some absolute state of perfect physical and mental well-being. It is—Canguilhem again—the “margin of tolerance for the inconsistencies of the environment.” Seen this way, solutions to the puzzles of disease will be found using methods we probably do not yet possess. Doctors will eventually stop chasing after diseases as things-in-themselves. They will devote more and more attention to the conditions that bring about disease. Medicine is not so much in free fall as it is on a plateau with an empty horizon.