The epistemology of Ludwik Fleck and the thought community of Banff: reflections on the classification of the renal allograft pathology.

Ludwik Fleck was a polish physician and bacteriologist with major interest in epistemology. In 1935, he published, in German, a monograph entitled 'Genesis and development of a scientific fact'. His concepts of 'thought collective', 'thought style' and 'active and passive associations' have been materialized in Banff classification of renal allograft pathology. The dynamics and evolution of the classification of renal allograft pathology, generated within Banff community, reflect perfectly Fleck's conceptions. In this essay, the Banff community of thought is characterized as a thought collective, according to Fleck's epistemology. Since its inception, the classification has been evolving in a continuum of active and passive connections, preserving its initial thought style, based on morphology. Whether the emergence of nonmorphological, molecular techniques will result in the end of morphological thought style is a question the community is presently facing.