Scientism recognizes evidence only of the quantitative/general variety

RATIONALE, AIMS AND OBJECTIVES: McHugh and Walker introduced a model of knowledge to demonstrate that EBM is a form of scientism that ignores important sources of knowledge thereby impairing the practice of medicine. We study the development of this model and explore additional applications. METHODS: Review of the relevant literature and identification of possible areas for fruitful application. RESULTS: We show that the McHugh and Walker model is closely related to the model of evidence considered earlier by Upshur et al. We also indicate that the utility of this model is not limited to showing scientism distorts clinical practice. Several representative applications are identified, including psychotherapy, the Salk polio vaccine trial, and the placebo effect. CONCLUSIONS: Priority should be given to Upshur et al for the development of a model that has far-reaching application to medical epistemology. It is shown that all four of the types of evidence considered-qualitative/personal, qualitative/general, quantitative/general, and quantitative/personal-are required to adequately characterize epistemology in medical research and practice.