ABSTRACT
Thomas Kuhn and Helene Metzger might appear to belong to rather different eras: she anchored to the interwar period, he solidly belonging to side of the Second World War, and an enduring philosophical presence. Kuhn also included Metzger’s work among those histories of individual sciences that for him marked a new trend, in opposition to the previous attempts at general history of science, from Francis Bacon’s and Auguste Comte’s, to P. Tannery’s and George Sarton’s. Metzger traced the history of classification of the natural world, including the phases in which there was no clear distinction between minerals, vegetable and animal kingdoms. The lesson that Metzger learned from chemistry and in general the study of matter is that impurity is the motor of change and advancement. The impurity of chemistry also translated in an ‘impure’ view of historiography, epistemology and hermeneutics.
