To show why and how, without underestimating the popular perception of the word 'rheumatism', a medical approach to rheumatic diseases needs to consider the distinction between nosology (the study of diseases) and pathology [anatomopathology (the study of lesions) and physiopathology (the study of functional disturbances)].
Selected quotations reflecting the thought processes of two famous physicians whose clinical activity (orientated towards nosology) was firmly based on pathology (mainly physiopathology in the case of A. B. Garrod and mainly anatomopathology in the case of J.-M. Charcot) are discussed.
Starting from the physiopathological criterion of hyperuricaemia in gout, Garrod's thought processes led him to name and study rheumatoid arthritis. Alongside his neurological work, Charcot's thought processes led him to underline the common anatomical changes which could be observed in some nosologically distinct forms of chronic rheumatism.
Selected older texts of both authors provide good examples of a methodology which can still be useful for present-day rheumatologists, particularly during their training period. They could serve as a guide to clarify some semantic ambiguities concerning nosology and pathology and for a better understanding of some clinical and radiological overlaps between distinct nosological entities.