Terminology matters in medical ethics: on the use of 'diagnosis' in philosophical analysis.

Bair's recent article (J Med Ethics, 2026) offers a thoughtful Wittgensteinian analysis of 'understanding' in informed consent which proposes that comprehension should be evaluated through demonstrated capacity rather than passive reception. However, the author's choice to frame this conceptual clarification as a 'Wittgensteinian diagnosis' introduces significant terminological confusion. In clinical medicine, a 'diagnosis' represents a rigorous, empirical and consequential judgement derived from systematic assessment and differential analysis, with consequences for subsequent management. Borrowing this clinical term as an unmarked metaphorical transfer of clinical terminology for philosophical conceptual analysis risks misleading clinician-readers into expecting a novel diagnostic instrument, psychological scale or psychiatric evaluation framework. In an interdisciplinary journal dedicated to medical ethics like the Journal of Medical Ethics, precision in terminology is essential. Humanistic inquiries intersecting with clinical medicine must respect the specific weight and established operational definitions of clinical vocabulary. This response argues that referring to a purely philosophical clarification as a 'diagnosis' undermines clear communication between philosophers and clinicians. Conceptual errors are best designated as conceptual errors-not medical conditions requiring 'diagnosis.'