How Doctors Think: Clinical Judgment and the Practice of Medicine

Kathryn Montgomery is a professor of medical humanities at Northwestern University in the United States and a literary scholar by training. Her thesis is that doctors (and patients) misrep-resent medicine as an invariant, replicable science, and that this misunderstanding causes harm. It harms patients because they have unrealistic expectations of outcomes, and it harms doctors who are deluded into thinking that they should be operating scientifically and so become either “unnecessarily impersonal” or “disheartened.” Montgomery believes that medicine is best described not as a science but as “practical reasoning” or, in her terminology, “phronesis” (ouch!).

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Kathryn Montgomery

Oxford University Press, £23.99/$39.50, pp 208 ISBN 0 19 518712 1

Rating: Rating: ★★⋆⋆

She is a sympathetic and sometimes incisive observer of the practice of clinical judgment. And she writes movingly about her own personal experience when her daughter was diagnosed as having breast cancer at 28. Her prose, when she avoids neologisms, is lucid and easy to read.

While overall I enjoyed her book, I felt, however, that Montgomery rather overstated her thesis. Doctors do not really think that medicine functions as a science with “invariable replicability and rule like precision.” The “atoms” of medicine are “diagnoses,” which most doctors view not as absolute truths but as pragmatic classifications that allow grouping of phenomena for study and treatment. A student first on the ward sees the diversity of human suffering and quickly learns that the “classic case of...”is classic only in the sense that a 1920 Bugatti is classic—meaning extremely rare. Medicine is usually a morass of detail with barely discernible patterns and all doctors know that. Either Montgomery is setting up a fictional doctor stereotype to argue against (a perfectly reasonable stratagem) or else they are an odd lot she comes across at Northwestern University.

The author starts by arguing that the old “medicine as an art or medicine as a science” debate is a bit passé. But she immediately replaces it with a (to me largely indistinguishable) dichotomy of, on the one hand, medicine as modelled by linear causation and physician deduction, and on the other, medicine as messy (but warm) patient narrative. Montgomery professes to believe that medicine requires a fusion of the two, but there is a hint that this dichotomy is manifest as cold rationalist doctors (who presumably have not attended her course) and nice sympathetic ones (who can quote Proust). She states that, rather than scientific deduction, “moral knowing is the essence of clinical method.” The trouble is that I have no idea what that means, which leaves me in an uncertain quandary as to whether the problem is mine—and I am just ignorant of certain key philosophical concepts (which is definitely possible)—or whether it is a great phrase but a bit meaningless.

The key problem for me is that I do not really recognise the author's description of science. I suspect that she creates it merely as a rhetorical device, but hers is a cartoon depiction of the mad logician—an exaggerated belief in the powers of axiomatic deduction that actually disappeared with the logical posivitists half a century ago. Certainly medicine would sit uncomfortably within that particular white tower. While the law of gravitation applies to everything, the clinician's generalised truths are more modest beasts, hedged in with uncertainty and littered with caveats waiting to trip up the unwary.

The author writes nicely about clinical judgment and rightly states that attempts to mimic the judgments of experienced clinicians algorithmically mostly fail. This difficulty of encapsulating clinical judgment by clear rules is illustrated by the quote from Feigenbaum (he of complexity theory) about physician reasoning: “At this point knowledge threatens to break down into ten thousand special cases.” It is like Leibniz's observation that a rule or theory has to be simpler than the data it explains or it is useless. “Laws” in medicine often teeter on that brink. Occam's razor works for falling bodies, but not in the over-80s. The complexity of medicine defies easy codification and that is the clinician's problem. The author draws out some of these interesting points but then blows it by saying that expert clinicians reason not by methodical inference but “holographicly.” What on earth does that mean?

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Montgomery argues as though medical science seeks to banish illness from the world by imposing simplistic models on human suffering. But this is a tabloid view of scientific medicine. The reason why scientific rationalism must stay at the centre of medicine, and the author's medical humanities course, while laudable, must stay on the periphery, is that scientific scepticism sets limits on error. The history of medicine is big on error and, if you pick up the Daily Mail, you'll find there's still a bit of it about.

The idea that clinicians apply contextless scientific models and thus miss what the patient is telling them is, I think, mostly wrong. That debate was had 20 years ago and the listening doctors won. Patients are telling you stories and if you cannot hear the stories you foul up the job. Even we hard nosed rationalists accept that. But medicine must not kid itself. It lies, and has to lie, within the walls of systematic scepticism and scientific rationalism because outside that citadel are not dragons, but charlatans. And they will have you on an anti-ageing cream before you can say “candida allergy.”