ABSTRACT
The idea of a conceptual scheme is elusive. It is notoriously difficult to define criteria for marking one conceptual scheme from another or to explain how it is possible to apprehend a conceptual scheme from within a particular and different one. Coexistence and interaction of the Catholic with the chemist are possible to the extent that there is much that they share in the face of the disagreement. Indeed, their shared conception of ordinary genetics and ordinary chemistry makes it possible for them to understand and express their disagreement, its nature and limits. The notion of a shared practice is elastic and inexact, and necessarily so. A determination of what is a shared standard used differently and what is a different standard can only be made case by case. The situation of the Catholic and the chemist is atypical among examples of so-called different "conceptual frameworks."
