The doctrine of affinity deserves to be recognised by historians of chemistry as
the foundational basis of the discipline of chemistry as it was practiced in
Britain during the 18th century. It attained this status through its crucial
structural role in the pedagogy of the discipline. The importance of pedagogy
and training in the practice of science is currently being reassessed by a number
of historians, and my research contributes to this historiographical endeavour.
My analysis of the variety of theories sheltered under the umbrella term ‘affinity
theory’ has emphasised the role of pedagogy in influencing both the structure
and the content of knowledge. I have shown that there were wide ranging
discrepancies between many of the components of individual affinity theories.
Nevertheless, the scope of divergence was limited. This underlying organisation
resulted from the unifying hub of affinity theory, the logical common ground.
This was the essence of the doctrine of affinity, encompassing the law of affinity
and the conceptualisation of the table that brought together the relations
described in the law. The doctrine of affinity thus provided a disciplinary
common ground between chemists, providing a mediating level of
understanding and communication for all those who subscribed to the doctrine
of affinity, in spite of their detailed differences