Hance, J.R., Rarity, J. & Ladyman, J. Could wavefunctions simultaneously represent knowledge and reality?. Quantum Stud.: Math. Found. (2022). DOI: https://doi.org/10.1007/s40509-022-00271-3
In discussion of the interpretation of quantum mechanics the terms ‘ontic’ and ‘epistemic’ are often used in the sense of pertaining to what exists, and pertaining to cognition or knowledge respectively. The terms are also often associated with the formal definitions given by Harrigan and Spekkens for the wavefunction in quantum mechanics to be ψψ-ontic or ψψ-epistemic in the context of the ontological models framework. The formal definitions are contradictories, so that the wavefunction can be either ψψ-epistemic or ψψ-ontic but not both. However, we argue, nothing about the informal ideas of epistemic and ontic interpretations rules out wavefunctions representing both reality and knowledge. The implications of the Pusey–Barrett–Rudolph theorem and many other issues may be rethought in the light of our analysis.