Newman's Grammar of Assent and the Diagnostic Process

NEWMAN'S GRAMMAR OF ASSENTED THE DIAGNOSTIC PROCESS WILLIAM BEAUTYMAN* Newman's Idea of a University [1] is frequently quoted in connection with medical education, but the relevance of his Grammar of Assent to diagnosis has had scant recognition [2-4]. Yet the making of a diagnosis is essentially a matter of giving assent to a proposition, for example, Mrs. Jones has subacute bacterial endocarditis; and in Newman's work, we have the most comprehensive and elegant treatment of the subject in the English language. Indeed, it adumbrates many of the more recent observations that have been made on the nature of science and diagnosis, and it brings together many aspects of human thought relevant to such matters that are elsewhere treated in isolation, if at all. Real and Notional Assent Newman divided assents into two classes, "real" and "notional," the former being assents to propositions concerning things, such as "the book is on the table"; the latter to ideas, notions, concepts, or abstractions , such as "too much money chasing too few goods causes inflation." Both kinds ofassent are involved in diagnosis, for example, real assent to a diagnosis of spiral fracture of the left tibia and notional assent to a diagnosis such as disseminated lupus erythematosus. Newman recognized that in medicine notional assent tends to predominate: "Pathology and medicine, in the interests of science, and as a protection to the practioner, veil the shocking realities of disease and physical suffering under a notional phraseology; under the abstract term¿ of debility, distress , irritability, paroxysm, and a host of Greek and Latin words. The arts of medicine and surgery are necessarily experimental, but for writA discussion ofJ. H. Newman, An Essay in Aid ofa Grammar ofAssent (1870; reprint ed., Carden City, N.Y.: Doubleday, 1955). *Professor of pathology, University of Massachusetts Medical School, Berkshire Medical Center, 725 North Street, Pittsfield, Massachusetts 01201.© 1982 by The University of Chicago. All rights reserved. 003 1 -5982/82/2503-0292$0 1.00 472 I William Beautyman ¦ Diagnostic Process ing and conversing on these subjects they require to be stripped of the association of the facts from which they are derived." The predominance of notional assent in diagnosis has been recently recognized by Campbell, Scadding, and Roberts [5] and Scadding [6] as important in the consideration of the definition of disease and of diagnosis . Their terms "realist" or "essentialist" can be roughly related to what Newman calls real assent, and their term "nominalist" can be roughly related to Newman's notional assent. They emphasize that in diagnosis the physician takes a predominantly nominalist stance, but they point out that the reification of the names of diseases frequently causes problems in medical discussion. Newman considered that assent was unconditional and took issue with Locke's view that, with rare exceptions, assent should be given only to probabilities. Newman, however, was concerned not with what should happen but with what actually does happen, and he maintained that, although assent may be given to a probability, unconditional assent is common. As far as diagnosis is concerned, Newman's view is certainly true. Physicians frequently give unconditional assent to such propositions as "Mr. Jones has a myocardial infarction" or "Mrs. Smith has carcinoma of the breast with metastases to bone," even though these diagnoses may be mistaken. It would require a special forced effort on the part of the physician to assign some probability to what has been accepted by his mind as quite certain. Diagnosis as Hypothetico-Deductive Diagnosis obviously involves the consideration of possibilities analogous to the consideration of hypotheses to account for scientific observations . By analogy with what was considered to be the scientific method, diagnosis has been considered to be a matter of gathering all the facts before "inducing" the diagnosis. It is now generally recognized that hypotheses are generated very early in both diagnostic and scientific practice when only a few facts have been gathered, and inferences from these hypotheses are tested by further observations (the so-called hypothetico-deductive approach). Throughout his work Newman is critical of the inductive method, and, while he discusses inference in depth, he considers that induction alone plays only a small role in assent. Most physicians have...