This project examines the role of Niels Bohr’s notion of classical concepts in the use and interpretation of quantum theory, and explores its operational consequences. Prior work has shown that Bohr’s “classical concepts” are conceptually distinct from “classical mechanics”: whereas classical mechanics concerns dynamical laws, classical concepts concern the epistemic and linguistic preconditions required to describe experiments and communicate their results (see, for example, Faye’s reconstruction of Bohr).

In the first part of the project, I investigate how these epistemic and linguistic preconditions might be formalized. In particular, they involve (i) the capacity to describe experimental outcomes as definite occurrences in ordinary language, and (ii) the capacity to communicate such occurrences intersubjectively.

In the second part, I explore how this formalization can be applied to concrete physical scenarios, and what logical and conceptual consequences follow for the quantum–classical transition and for interpretations of quantum theory.