In defence of non-ontic accounts of quantum states

TL;DR

This paper defends non-ontic, epistemic interpretations of quantum states by analyzing objections and comparing different epistemic approaches, emphasizing their philosophical and interpretative advantages.

Contribution

It proposes a refined epistemic account combining ideas from Friederich and Healey, and critically examines objections against epistemic quantum state interpretations.

Findings

Addresses key objections to epistemic quantum states

Compares the proposed account with quantum Bayesian views

Highlights philosophical benefits of non-ontic interpretations

Abstract

The paper discusses objections against non-hidden variable versions of the epistemic conception of quantum states - the view that quantum states do not describe the properties of quantum systems but reflect, in some way to be specified, the epistemic conditions of agents assigning them. In the first half of the paper, the main motivation for the epistemic conception of quantum states is sketched, and a version of it is outlined, which combines ideas from an earlier study of it [Friederich 2011] with elements of Richard Healey's recent pragmatist interpretation of quantum theory [Healey 2012]. In the second half, various objections against epistemic accounts of quantum states are discussed in detail, which are based on criticisms found in the literature. Possible answers by the version outlined here are compared with answers from the quantum Bayesian point of view, which is at present the most discussed version of the epistemic conception of quantum states.