By Takeo Saio

I trained as a psychiatrist in Japan at a moment when the field was still, in many ways, German. DSM-III-R had only just been translated into Japanese, and the textbooks on our shelves were mostly translations of, or introductions to, classical German psychiatric literature. We read Karl Jaspers and Kurt Schneider, closely, not as a historical curiosity but as the working grammar of descriptive psychopathology.

So when, decades later, I came across the title “Grammar of ‘understanding’ in informed consent: a Wittgensteinian diagnosis,” by Henry Bair, I did what I suspect most psychiatrists of my generation would have done. I stopped and read it immediately.

Wittgenstein? Diagnosing something?

By coincidence, I happened to be reading a Japanese introduction to Wittgenstein at the time, so seeing his name in the table of contents of a medical ethics journal felt almost like running into an old acquaintance in an unexpected place.

Bair’s paper turned out to be a careful and genuinely interesting piece of work. Drawing on Wittgenstein’s Philosophical Investigations, he argues that informed-consent practice mistakes “understanding” for something that happens inside a patient’s head when information is delivered, rather than a capacity the patient can demonstrate. Once I read past the title, I found the argument persuasive. The practical recommendation—to ask patients to restate information in their own words rather than simply asking “do you understand?”—is one I would happily adopt in my own practice.

But the title stayed with me.

In clinical medicine, “diagnosis” is not a decorative word. It is the outcome of a structured process, with direct consequences for what happens to a patient next. In Japan, there is a long-standing, largely unwritten professional understanding that diagnosis belongs primarily to the physician’s clinical judgement. Other professions may have their own forms of assessment, and terms like “nursing diagnosis” or “pharmacological diagnosis” are well established. But the word “diagnosis” carries a particular weight for physicians, and that weight does not necessarily travel with the word when it crosses disciplinary boundaries.

That is the ear with which I was reading Bair’s title.

Wittgenstein himself, of course, spoke of philosophy as a kind of therapy for conceptual confusion, so there is genuine precedent within his own writing for the medical vocabulary Bair borrows. My concern is therefore not with metaphor as such. It is with where the metaphor is placed.

A title appearing in a journal whose readership includes many practising clinicians, attached to a paper that turns out to be a philosophical argument rather than a clinical or empirical study, can easily be read in a clinical sense. That was almost how I read it myself: as an announcement of some new diagnostic instrument, method, or assessment protocol.

That expectation was understandable. It was also, as I discovered, wrong.

That brief hesitation stayed with me, and eventually led me to write a response to the paper for the Journal of Medical Ethics. My response was not a criticism of Bair’s philosophical argument, which I found persuasive, but a small terminological point about what happens when the word “diagnosis” crosses the boundary between philosophy and clinical medicine. Philosophy and clinical medicine both use the language of diagnosis, but the word does not necessarily perform the same function in the two disciplines. Interdisciplinary journals are precisely where such differences become important.

Perhaps the lesson is a modest one. When a word carries substantial professional meaning in one field and is borrowed by another, readers should not be expected to work out from context which sense is intended. Precision in terminology matters—not because disciplinary boundaries should be rigid, but because crossing those boundaries is most fruitful when we are clear about what we are carrying with us.

Paper title: Terminology Matters in Medical Ethics: On the Use of “Diagnosis” in Philosophical Analysis

Author: Takeo Saio

Affiliation: Fuji Toranomon Orthopedic Hospital, Department of Internal Medicine and Psychiatry

Competing interests: None declared