Incommensurability: its implications for the patient/physician relation.

Scientific authority and physician authority are both challenged by Thomas Kuhn's concept of incommensurability. If competing "paradigms" or "world views" cannot rationally be compared, we have no means to judge the truth of any particular view. However, the notion of local or partial incommensurability might provide a framework for understanding the implication of contemporary philosophy of science for medicine. We distinguish four steps in the process of translating medical science into clinical decisions: the doing of the science, the appropriation of the scientific findings by the clinician, the transfer of the findings from the clinician to the patient, and the choice of a treatment regimen. Incommensurability can play a role in each stage. There is at least some theory- and value-ladenness in science that is dependent on the world view of those who construct the scientific theories. Clinicians who must use the results of scientific research will inevitably interpret the research from the standpoint of their own world view. There may be further incommensurability when these data are communicated to the patient. Finally, clinician and patient values must come into play in any decision about choice of treatment. No stage of medical research or practice is value-free. This position does not imply relativism; some scientific accounts are better than others. However, the challenge of the incommensurabilists shows that further analysis is needed to establish how particular accounts are better or worse.